The following is a list of program that I wrote for a class that was taken during the Spring of 1999.  The programs were designed to function as tools in modeling physical situations.  These programs were written using Delphi 4, a compiler that uses object Pascal.  The links below will allow direct download of the files.  The programs are stand alone exe's that run with Windows.  (I have no idea about other OS's.)  In writing these programs, I made every attempt to prevent human error from crashing the program (i.e. dividing by zero, graphing infinity, etc...).  However, I didn't have that much time to spend on any one project.  So if you get really bored, have some fun trying to overload the programs.  The source code is available upon request by e-mailing me at tivaldes@davidson.edu.

 File Description Universal Gravitational Force Calculates the gravitational force between two objects.  Preset buttons contain planetary data. Integration using Simpson's Rule Numerical integrator that uses Simpson's Rule as the algorithm (yeah, that's not too much of a help). First and Second Derivatives Calculates the first and second derivative of a function at a certain point. Random Walker Classic problem with a random number generator whose parameters can be changed by the user. (Not the greatest thing in the world, some stuff just doesn't work.  I really ought to fix it sometime.) Coupled Differential Equations Graphically solves two coupled differential equations.  As an application, has scenario options for an arms race between the hypothetical countries of Ytterbium and Zirconium. Electronic Oscillations in an L,R,C circuit Models the charge as a function of time, or current versus charge, in an electrical circuit consisting of an inductor, a capacitor, and a resistor.  Effects such as damping and resonance are observed.  Driving the system with an outside force is also possible. Population of Electrons due to Thermal Phonons at Low Temperatures Models the electron population in a two energy level system as affected by thermal phonons carrying off heat, and therefore energy.  Based on a random number generator.  First of two final project for the course.  Don't forget to play "Capture the Particle." Upconversion Population of electrons in a three energy level system.  Models the effect on the system when excited by a laser and the relaxation of the system after the laser has been turned off.  Based on a set of three coupled differential equations.  Second of two final projects for the course.  I used this program in research conducted at the University of Georgia during the summer of 1999.  Don't forget to play "Capture the Particle."