trunk/models/atoms.a4l

REQUIRE "system.a4l";   (* => system.a4l, basemodel.a4l *)
REQUIRE "measures.a4l"; (* => measures.a4l *)
PROVIDE "atoms.a4l";

(*  ASCEND modelling environment
 *  Copyright (C) 1994-2006 Carnegie Mellon University
 *
 *  The ASCEND Modeling Library is free software; you can redistribute
 *  it and/or modify it under the terms of the GNU General Public
 *  License as published by the Free Software Foundation; either
 *  version 2 of the License, or (at your option) any later version.
 *
 *  The ASCEND Modeling Library is distributed in hope that it
 *  will be useful, but WITHOUT ANY WARRANTY; without even the implied
 *  warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
 *  See the GNU General Public License for more details.
 *
 *  You should have received a copy of the GNU General Public License
 *  along with the program; if not, write to the Free Software
 *  Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139 USA.
 *)

(*============================================================================*

    A  T  O  M  S  .  A  4  L
    -------------------------

    AUTHOR:      Joseph J. Zaher

    DATES:       07/91 - Original code.
                 02/92 - Eliminated "display_units" assignments, added
                         commonly used UNIVERSAL constants and transport
                         quantities.
                 04/92 - Added electro-magnetic quantities.
                 06/92 - Converted by Ben Allan to be compatible with ASCEND3C
		 08/92 - Additional monetary atoms added by Bob Huss
		 02/96 - Brought proper constants into the library. Ben Allan.
                 07/96 - Incorporated Ken Tyner's substitution atoms. BAA.
		 07/96 - Switched to REQUIRE syntax.
		 08/96 - Switched to REQUIRE ivpsystem.a4l.
		 08/97 - Switched to REQUIRE/PROVIDE syntax.

    CONTENTS:    ASCEND atom definitions for engineering variable types.
                 Many of the anticipated dimensional variables which occur
                 in engineering design calculations are given to provide a
                 means of standardization.  Chosen defaults, nominal, and
                 lower and upper bound values should be re-specified if
                 necessary to enhance the convergence properties of
                 specific models.  Units to be displayed are to be controlled
                 using the UNITS tool kit of the environment.

    REQUIRES:   see top of file.

    This file by Joseph J. Zaher, Benjamin A. Allan, Robert S. Huss, John Pye
    Last in CVS: $Date: 1998/08/17 13:07:11 $ $Revision: 1.11 $

 *===========================================================================*)

(*  G E N E R I C    C O N S T A N T S      ( C H E M .  E .   B I A S )
    --------------------------------------------------------------------  *)

    CONSTANT constant
    (* any sloppiness about what is a constant will yield a wild real *)
    REFINES real_constant;

    (* dimensionless *)

    CONSTANT critical_compressibility REFINES real_constant DIMENSIONLESS;

    CONSTANT acentric_factor REFINES real_constant DIMENSIONLESS;

    CONSTANT UNIFAC_size REFINES real_constant DIMENSIONLESS;

    CONSTANT Wilson_constant REFINES real_constant DIMENSIONLESS;

    CONSTANT vapor_pressure_constant REFINES real_constant;

    CONSTANT factor_constant REFINES real_constant DIMENSIONLESS;

    (* molecular weight *)
    CONSTANT molar_weight_constant
    REFINES real_constant DIMENSION M/Q;

    (* atomic mass *)
    CONSTANT atomic_mass_constant
    REFINES real_constant DIMENSION M;

    (* temperatures *)
    CONSTANT temperature_constant
    REFINES real_constant DIMENSION TMP;

    CONSTANT boiling_temperature
    REFINES temperature_constant;

    CONSTANT critical_temperature
    REFINES temperature_constant;

    CONSTANT reference_temperature
    REFINES temperature_constant;

    CONSTANT UNIFAC_a
    REFINES temperature_constant;

    (* pressures *)
    CONSTANT pressure_constant
    REFINES real_constant DIMENSION M/L/T^2;

    CONSTANT critical_pressure
    REFINES pressure_constant;

    CONSTANT reference_pressure
    REFINES pressure_constant;

    (* molar volumes *)
    CONSTANT molar_volume_constant
    REFINES real_constant DIMENSION L^3/Q;

    CONSTANT critical_volume
    REFINES molar_volume_constant;

    CONSTANT reference_molar_volume
    REFINES molar_volume_constant;

    (* mass densities *)
    CONSTANT reference_mass_density
    REFINES real_constant DIMENSION M/L^3;

    (* molar energies *)
    CONSTANT molar_energy_constant
    REFINES real_constant DIMENSION M*L^2/T^2/Q;

    CONSTANT reference_molar_energy
    REFINES molar_energy_constant;

    CONSTANT enthalpy_of_formation_constant
    REFINES molar_energy_constant;

    CONSTANT free_energy_of_formation_constant
    REFINES molar_energy_constant;

    CONSTANT heat_of_vaporization_constant
    REFINES molar_energy_constant;

    CONSTANT Wilson_energy_constant
    REFINES molar_energy_constant;

    (* molar entropies *)
    CONSTANT molar_entropy_constant
    REFINES real_constant DIMENSION M*L^2/T^2/Q/TMP;

    CONSTANT reference_molar_entropy
    REFINES molar_entropy_constant;

    (* other strange correlation coefficients *)
    CONSTANT heat_capacity_constant
    REFINES real_constant;

    CONSTANT heat_capacity_a_constant
    REFINES heat_capacity_constant DIMENSION M*L^2/T^2/Q/TMP;

    CONSTANT heat_capacity_b_constant
    REFINES heat_capacity_constant DIMENSION M*L^2/T^2/Q/TMP^2;

    CONSTANT heat_capacity_c_constant
    REFINES heat_capacity_constant DIMENSION M*L^2/T^2/Q/TMP^3;

    CONSTANT heat_capacity_d_constant
    REFINES heat_capacity_constant DIMENSION M*L^2/T^2/Q/TMP^4;

(*
    CONSTANT
    REFINES real_constant DIMENSION;
*)

(*  U N I V E R S A L    C O N S T A N T S
    --------------------------------------  *)

    UNIVERSAL CONSTANT gas_constant
    (* DIMENSION M*L^2/T^2/Q/TMP *)
    REFINES real_constant :== 1{GAS_C};

    UNIVERSAL CONSTANT gravity_constant
    (* DIMENSION L/T^2 *)
    REFINES real_constant :== 1{EARTH_G};

    UNIVERSAL CONSTANT circle_constant
    REFINES real_constant :== 1{PI};

    UNIVERSAL CONSTANT speed_of_light
    REFINES real_constant :== 1{LIGHT_C};

    UNIVERSAL CONSTANT planck_constant
    (* DIMENSION M*L^2/T *)
    REFINES real_constant :== 1{PLANCK_C};

    UNIVERSAL CONSTANT avogadro_constant
    REFINES real_constant :== 1{AVOGADRO_C};

    UNIVERSAL CONSTANT permittivity_constant
    (* DIMENSION E^2*T^4/M/L^3 *)
    REFINES real_constant :== 1{EPSILON0};

    UNIVERSAL CONSTANT permeability_constant
    REFINES real_constant :== 1{MU0};

    UNIVERSAL CONSTANT electron_charge
    REFINES real_constant :== 1{eCHARGE};

    UNIVERSAL CONSTANT electron_mass
    REFINES real_constant :== 1{eMASS};

    UNIVERSAL CONSTANT proton_mass
    REFINES real_constant :== 1{pMASS};

   (* B O O L E A N S   *)

(* use these booleans *)
ATOM boolean_start_true REFINES boolean
    DEFAULT  TRUE;
END boolean_start_true;

ATOM boolean_start_false REFINES boolean
    DEFAULT  FALSE;
END boolean_start_false;

(* for backward compatibility *)
ATOM start_true REFINES boolean
    DEFAULT  TRUE;
END start_true;

ATOM start_false REFINES boolean
    DEFAULT  FALSE;
END start_false;


   (* P A R A M E T E R S *)

UNIVERSAL ATOM bound_width REFINES real
    (* not really a constant but a parameter to tell us how wide to
     * put bounds from the current point, in relative terms.
     * e.g. a.upper_bound := a + a.nominal * bound_width_instance;
     *)
    DIMENSIONLESS
    DEFAULT 1.0e8;
END bound_width;

UNIVERSAL ATOM scaling_constant REFINES real
    (* not really a constant but a parameter. which
     * needs problem dependent information to be useful.
     *)
    DIMENSIONLESS
    DEFAULT 1.0;
END scaling_constant;

UNIVERSAL ATOM ode_counter REFINES integer
    DIMENSIONLESS
    DEFAULT 1;
END ode_counter;

UNIVERSAL ATOM obs_counter REFINES integer
    DIMENSIONLESS
    DEFAULT 1;
END obs_counter;

ATOM real_parameter REFINES real;
END real_parameter;

ATOM length_parameter REFINES real_parameter
    DIMENSION  L
    DEFAULT 1.0 {m};
END length_parameter;


(*  D I M E N S I O N L E S S  Q U A N T I T I E S
    ----------------------------------------------  *)

    ATOM positive_variable REFINES solver_var
    (* one for the gams folks *)
        DIMENSIONLESS
        DEFAULT 1.0;
        lower_bound := 0.0;
        upper_bound := 1e20;
        nominal := 1.0;
    END positive_variable;

    ATOM factor REFINES solver_var
        DIMENSIONLESS
        DEFAULT 1.0;
        lower_bound := -1e50;
        upper_bound := 1e50;
        nominal := 1.0;
    END factor;

    ATOM variable REFINES solver_var
	DIMENSIONLESS;
    END variable;


    ATOM fraction REFINES solver_var
        DIMENSIONLESS
        DEFAULT 0.5;
        nominal := 1.0;
        lower_bound := 0.0;
        upper_bound := 1.0;
    END fraction;

    ATOM positive_factor REFINES factor;
        lower_bound := 0.0;
    END positive_factor;

    ATOM small_factor REFINES factor;
        lower_bound := -10.0;
        upper_bound := 10.0;
    END small_factor;

    ATOM small_positive_factor REFINES factor;
        lower_bound := 0.0;
        upper_bound := 10.0;
    END small_positive_factor;

    ATOM reduced_pressure REFINES factor;
    END reduced_pressure;

(*  S U B S T I T U T I O N  V A R I A B L E S
    ------------------------------------------  *)
    ATOM exp_sub REFINES factor ;
        lower_bound := -1e50;
        upper_bound := 100;
        nominal := 1.0;
    END exp_sub;

    ATOM power_sub REFINES factor;
        lower_bound := -25;
        upper_bound := 25;
        nominal := 1.0;
    END power_sub;

(*  T E M P E R A T U R E
    ---------------------  *)

    ATOM temperature REFINES solver_var
        DIMENSION TMP
        DEFAULT 298.0{K};
        lower_bound := 1.0e-6{K};
        upper_bound := 10000{K};
        nominal := 298.0{K};
    END temperature;

    ATOM inverse_temperature REFINES solver_var
        DIMENSION 1/TMP
        DEFAULT 0.00366099{1/K};
        lower_bound := 0.0{1/K};
        upper_bound := 1e50{1/K};
        nominal := 0.00366099{1/K};
    END inverse_temperature;

    ATOM delta_temperature REFINES solver_var
        DIMENSION TMP
        DEFAULT 0.1{K};
        lower_bound := -1000{K};
        upper_bound := +1000{K};
        nominal := 5{K};
    END delta_temperature;

(* forces *)
    ATOM force REFINES solver_var
		DIMENSION M*L/T^2
		DEFAULT 1.0{N};
		lower_bound := -1e20{N};
		upper_bound := 1e20{N};
		nominal := 1.0{kN};
    END force;

	ATOM force_per_length REFINES solver_var
			DIMENSION M/T^2 
			DEFAULT 1.0{N/m};
		lower_bound := -1e20{N/m};
		upper_bound := 1e20{N/m};
		nominal := 1.0{N/m};
	END force_per_length;

	ATOM force_per_volume REFINES solver_var
			DIMENSION M/T^2/L^2
			DEFAULT 1.0{N/m^3};
		lower_bound := -1e20{N/m^3};
		upper_bound := 1e20{N/m^3};
		nominal := 1.0{N/m^3};
	END force_per_volume;

	ATOM surface_tension REFINES solver_var
			DIMENSION M/T^2 
			DEFAULT 1.0{N/m};
		lower_bound := 0{N/m};
		upper_bound := 1e20{N/m};
		nominal := 1.0{N/m};
	END surface_tension;

(*  P R E S S U R E
    ---------------  *)

    ATOM pressure REFINES solver_var
        DIMENSION M/L/T^2
        DEFAULT 1.0{atm};
        lower_bound := 0.001{Pa};
        upper_bound := 5000{atm};
        nominal := 1.0{atm};
    END pressure;
    
    ATOM delta_pressure REFINES solver_var
        DIMENSION M/L/T^2
        DEFAULT 1.0{atm};
		lower_bound := -1000{atm};
        upper_bound := 1000{atm};
        nominal := 1.0{atm};
    END delta_pressure;

    ATOM vapor_pressure REFINES pressure
        DIMENSION M/L/T^2
        DEFAULT 1.0{atm};
        lower_bound := 0.001{Pa};
        upper_bound := 5000{atm};
        nominal := 0.5{atm};
    END vapor_pressure;

    ATOM k_constant REFINES solver_var
    (* what IS this ? ? ? (it rings a bell...) *)
        DIMENSION T^2/L^5
        DEFAULT 1.0 {s^2/ft^5};
        lower_bound := 0.001 {s^2/ft^5};
        upper_bound := 5000 {s^2/ft^5};
        nominal := 1.0 {s^2/ft^5};
    END k_constant;

  	ATOM youngs_modulus REFINES solver_var
  		(* the measure of the physical stiffness of a material *)
  		DIMENSION M/L/T^2
  		DEFAULT 200 {GPa};
  		lower_bound := 0 {Pa};
  		upper_bound := 1500 {GPa};
  		nominal := 40 {GPa};
  	END youngs_modulus;

    ATOM pressure_per_length REFINES solver_var
        DIMENSION M/L^2/T^2
        DEFAULT 50 {Pa/m};
        lower_bound := -1e20{bar/m};
        upper_bound := +1e20{bar/m};
        nominal := 50 {Pa/m};
    END pressure_per_length;
  

(*  M A S S / M O L E  Q U A N T I T I E S
    --------------------------------------  *)

    ATOM molar_mass REFINES solver_var
        DIMENSION M/Q
        DEFAULT 100.0{g/g_mole};
        lower_bound := 0.0{g/g_mole};
        upper_bound := 1e9{g/g_mole};
        nominal := 100.0{g/g_mole};
    END molar_mass;

    ATOM mass REFINES solver_var
        DIMENSION M
        DEFAULT 10.0{kg};
        lower_bound := 0.0{kg};
        upper_bound := 1e50{kg};
        nominal := 10.0{kg};
    END mass;

    ATOM mole_scale REFINES real DIMENSION Q DEFAULT 1 {mole};
    END mole_scale;

    ATOM mole REFINES solver_var
        DIMENSION Q
        DEFAULT 10.0{lb_mole};
        lower_bound := 0.0{lb_mole};
        upper_bound := 1e50{lb_mole};
        nominal := 10.0{lb_mole};
    END mole;

    ATOM mass_rate REFINES solver_var
        DIMENSION M/T
        DEFAULT 50{g/s};
        lower_bound := 0.0{g/s};
        upper_bound := 1e50{g/s};
        nominal := 100.0{g/s};
    END mass_rate;

	ATOM mass_flux REFINES solver_var
        DIMENSION M/T/L^2
        DEFAULT 10{kg/s/m^2};
        lower_bound := -1e12{kg/s/m^2};
        upper_bound := 1e12{kg/s/m^2};
        nominal := 10.0{kg/s/m^2};
    END mass_flux;


    ATOM mass_rate_rate REFINES solver_var
        DIMENSION M/T^2
        DEFAULT 10{g/s/s};
        lower_bound := -1e50{g/s/s};
        upper_bound := 1e50{g/s/s};
        nominal := 10.0{g/s/s};
    END mass_rate_rate;

    ATOM mass_rate_per_length REFINES solver_var
        DIMENSION M/T/L
        DEFAULT 0.1 {kg/s/m};
        lower_bound := -1e50 {kg/s/m};
        upper_bound := 1e50 {kg/s/m};
        nominal := 1.0 {kg/s/m};
    END mass_rate_per_length;
	

    ATOM molar_rate_scale REFINES real DIMENSION Q/T DEFAULT 1 {mole/second};
    END molar_rate_scale;

    ATOM molar_rate REFINES solver_var
        DIMENSION Q/T
        DEFAULT 100.0{lb_mole/hour};
        lower_bound := 0.0{lb_mole/hour};
        upper_bound := 1e50{lb_mole/hour};
        nominal := 100.0{lb_mole/hour};
    END molar_rate;

    ATOM conc_rate REFINES solver_var
	DIMENSION Q/L^3/T
	DEFAULT 100.0{lb_mole/ft^3/hour};
	lower_bound := 0.0{lb_mole/ft^3/hour};
	upper_bound := 1e50{lb_mole/ft^3/hour};
	nominal := 100.0{lb_mole/ft^3/hour};
    END conc_rate;


    ATOM mole_fraction REFINES fraction
        DIMENSIONLESS
        DEFAULT 0.5;
        lower_bound := 0.0;
        nominal := 0.3;
        upper_bound := 1.0;
    END mole_fraction;

    ATOM mass_fraction REFINES fraction
        DIMENSIONLESS
        DEFAULT 0.5;
        lower_bound := 0.0;
        nominal := 0.3;
        upper_bound := 1.0;
    END mass_fraction;


(*  V O L U M E  Q U A N T I T I E S
    --------------------------------  *)

    ATOM molar_volume REFINES solver_var
        DIMENSION L^3/Q
        DEFAULT 1000.0{cm^3/g_mole};
        lower_bound := 0.0{cm^3/g_mole};
        upper_bound := 1e50{cm^3/g_mole};
        nominal := 1000.0{cm^3/g_mole};
    END molar_volume;

    ATOM volume_scale REFINES real DIMENSION L^3 DEFAULT 1.0 {m^3};
    END volume_scale;

    ATOM volume REFINES solver_var
        DIMENSION L^3
        DEFAULT 100.0{ft^3};
        lower_bound := 0.0{ft^3};
        upper_bound := 1e50{ft^3};
        nominal := 100.0{ft^3};
    END volume;

    ATOM volume_rate_scale REFINES real DIMENSION L^3/T DEFAULT 1{m^3/s};
    END volume_rate_scale;

    ATOM volume_rate REFINES solver_var
        DIMENSION L^3/T
        DEFAULT 100.0{gpm};
        lower_bound := 0.0{gpm};
        upper_bound := 1e50{gpm};
        nominal := 100.0{gpm};
    END volume_rate;

    ATOM volume_rate_square REFINES solver_var
        DIMENSION L^6/T^2
        DEFAULT 100.0{ft^6/s^2};
        lower_bound := 0.0{ft^6/s^2};
        upper_bound := 1e50{ft^6/s^2};
        nominal := 100 {ft^6/s^2};
    END volume_rate_square;

    ATOM volume_expansivity REFINES solver_var
        DIMENSION 1/TMP
        DEFAULT 0.001{1/K};
        lower_bound := 0.0{1/K};
        upper_bound := 1e50{1/K};
        nominal := 0.001{1/K};
    END volume_expansivity;


(*  D E N S I T Y  Q U A N T I T I E S
    ----------------------------------  *)

    ATOM molar_density REFINES solver_var
        DIMENSION Q/L^3
        DEFAULT 0.1{mole/m^3};
        lower_bound := 0.0{mole/m^3};
        upper_bound := 1e50{mole/m^3};
        nominal := 0.1{mole/m^3};
    END molar_density;

    ATOM mass_density REFINES solver_var
        DIMENSION M/L^3
        DEFAULT 1.0{g/cm^3};
        lower_bound := 0.0{g/cm^3};
        upper_bound := 1e50{g/cm^3};
        nominal := 1.0{g/cm^3};
    END mass_density;


(*  E N E R G Y  Q U A N T I T I E S
    ------------------------------------  *)

    ATOM molar_energy REFINES solver_var
        DIMENSION M*L^2/T^2/Q
        DEFAULT 10000.0{BTU/lb_mole};
        lower_bound := -1e50{BTU/lb_mole};
        upper_bound := 1e50{BTU/lb_mole};
        nominal := 10000.0{BTU/lb_mole};
    END molar_energy;

    ATOM energy_scale REFINES real DIMENSION M*L^2/T^2 DEFAULT 1{joule};
    END energy_scale;

    ATOM energy REFINES solver_var
        DIMENSION M*L^2/T^2
        DEFAULT 100000.0{BTU};
        lower_bound := -1e50{BTU};
        upper_bound := 1e50{BTU};
        nominal := 100000.0{BTU};
    END energy;

    ATOM energy_rate_scale REFINES real DIMENSION M*L^2/T^3 DEFAULT 1{watt};
    END energy_rate_scale;

    ATOM energy_rate REFINES solver_var
        DIMENSION M*L^2/T^3
        DEFAULT 100000.0{BTU/hour};
        lower_bound := -1e50{BTU/hour};
        upper_bound := 1e50{BTU/hour};
        nominal := 100000.0{BTU/hour};
    END energy_rate;

	ATOM power_per_length REFINES solver_var
        DIMENSION M*L/T^3
        DEFAULT 1.0{kW/m};
        lower_bound := -1e50{kW/m};
        upper_bound := 1e50{kW/m};
        nominal := 1.0{kW/m};
    END power_per_length;

	ATOM irradiance REFINES solver_var
		DIMENSION M/T^3
		DEFAULT 1000{W/m^2};
		lower_bound := 0{W/m^2};
		upper_bound := 1.5{MW/m^2}; (* a bit more that the max possible from sunlight *)
		nominal := 300{W/m^2};
	END irradiance;

	ATOM irradiation REFINES solver_var
		DIMENSION M/T^2
		DEFAULT 1000{J/m^2};
		lower_bound := 0{J/m^2};
		upper_bound := 1e50{J/m^2}; (* a bit more that the max possible from sunlight *)
		nominal := 300{J/m^2};
	END irradiation;


    ATOM molar_heat_capacity REFINES solver_var
        DIMENSION M*L^2/T^2/Q/TMP
        DEFAULT 1.00e5{J/mole/K};
        lower_bound := 0.0{J/mole/K};
        upper_bound := 1e60{J/mole/K};
        nominal := 1.00e5{J/mole/K};
    END molar_heat_capacity;

    ATOM molar_energy_rate REFINES solver_var
        DIMENSION M*L^2/T^3/Q
        DEFAULT 0 {BTU/lb_mole/h};
        lower_bound := -1e50 {BTU/lb_mole/h};
        upper_bound := 1e50 {BTU/lb_mole/h};
        nominal := 10000.0 {BTU/lb_mole/h};
    END molar_energy_rate;

(*  E N T R O P Y  Q U A N T I T I E S
    ----------------------------------  *)

    ATOM molar_entropy REFINES solver_var
        DIMENSION M*L^2/T^2/Q/TMP
        DEFAULT 100.0{BTU/lb_mole/R};
        lower_bound := -1e50{BTU/lb_mole/R};
        upper_bound := 1e50{BTU/lb_mole/R};
        nominal := 100.0{BTU/lb_mole/R};
    END molar_entropy;

    ATOM entropy REFINES solver_var
        DIMENSION M*L^2/T^2/TMP
        DEFAULT 1000.0{BTU/R};
        lower_bound := -1e50{BTU/R};
        upper_bound := 1e50{BTU/R};
        nominal := 1000.0{BTU/R};
    END entropy;

    ATOM entropy_rate REFINES solver_var
        DIMENSION M*L^2/T^3/TMP
        DEFAULT 1000.0{BTU/hour/R};
        lower_bound := -1e50{BTU/hour/R};
        upper_bound := 1e50{BTU/hour/R};
        nominal := 1000.0{BTU/hour/R};
    END entropy_rate;


(*  E Q U I L I B R I U M  Q U A N T I T I E S
    ------------------------------------------  *)

    ATOM partition_coefficient REFINES factor (* new *)
        DEFAULT 1.0;
        lower_bound := 1.0e-10;
        upper_bound := 30.0;
        nominal := 1.0;
    END partition_coefficient;

    ATOM relative_volatility REFINES partition_coefficient; (* new *)
    END relative_volatility;


(*  M O N E T A R Y  Q U A N T I T I E S
    ------------------------------------  *)

    ATOM monetary_unit REFINES solver_var
        DIMENSION C
        DEFAULT 100.0{USD};
        lower_bound := -1e50{USD};
        upper_bound := 1e50{USD};
        nominal := 100.0{USD};
    END monetary_unit;

	ATOM cost_per_volume REFINES solver_var
        DIMENSION C/L^3
        DEFAULT 1.0{USD/gallon};
        lower_bound := 0.0{USD/gallon};
        upper_bound := 1e50{USD/gallon};
        nominal := 1.0{USD/gallon};
	END cost_per_volume;

	ATOM cost_per_mass REFINES solver_var
        DIMENSION C/M
        DEFAULT 1.0{USD/lbm};
        lower_bound := 0.0{USD/lbm};
        upper_bound := 1e50{USD/lbm};
        nominal := 1.0{USD/lbm};
	END cost_per_mass;

	ATOM cost_per_mole REFINES solver_var
        DIMENSION C/Q
        DEFAULT 1.0{USD/lb_mole};
        lower_bound := 0.0{USD/lb_mole};
        upper_bound := 1e50{USD/lb_mole};
        nominal := 1.0{USD/lb_mole};
	END cost_per_mole;

	ATOM cost_per_time REFINES solver_var
        DIMENSION C/T
        DEFAULT 1.0{USD/min};
        lower_bound := 0.0{USD/min};
        upper_bound := 1e50{USD/min};
        nominal := 1.0{USD/min};
	END cost_per_time;

	ATOM cost_per_energy REFINES solver_var
        DIMENSION C*T^2/M/L^2
        DEFAULT 1.0{USD/BTU};
        lower_bound := 0.0{USD/BTU};
        upper_bound := 1e50{USD/BTU};
        nominal := 1.0{USD/BTU};
	END cost_per_energy;


(*  S U R V E Y I N G   Q U A N T I T I E S
    ---------------------------------------  *)

    ATOM distance REFINES solver_var
        DIMENSION L
        DEFAULT 10.0{ft};
        lower_bound := 0.0{ft};
        upper_bound := 1e50{ft};
        nominal := 10.0{ft};
    END distance;

    ATOM area REFINES solver_var
        DIMENSION L^2
        DEFAULT 10.0{ft^2};
        lower_bound := 0.0{ft^2};
        upper_bound := 1e50{ft^2};
        nominal := 10.0{ft^2};
    END area;

    ATOM inverse_area REFINES solver_var
        DIMENSION L^-2
        DEFAULT 1{1/ft^2};
        lower_bound := 0.0{1/ft^2};
        upper_bound := 1e50{1/ft^2};
        nominal := 1.0{1/ft^2};
    END inverse_area;

    ATOM angle REFINES solver_var
        DIMENSION P
        DEFAULT 1 {rad};
        lower_bound := -1e50 {rad};
        upper_bound := 1e50 {rad};
        nominal := 1 {rad};
    END angle;

    ATOM solid_angle REFINES solver_var
        DIMENSION S
        DEFAULT 1 {srad};
        lower_bound := -1e50 {srad};
        upper_bound := 1e50 {srad};
        nominal := 1 {srad};
    END solid_angle;

(*  M O T I O N   Q U A N T I T I E S
    ---------------------------------  *)

    ATOM time REFINES solver_var
        DIMENSION T
        DEFAULT 60.0{s};
        lower_bound := -1e50{s};
        upper_bound := 1e50{s};
        nominal := 60.0{s};
    END time;

    ATOM speed REFINES solver_var
        DIMENSION L/T
        DEFAULT 3.0{ft/s};
        lower_bound := -1e50{m/s};
        upper_bound := 1e50{m/s};
        nominal := 1.0{m/s};
    END speed;

    ATOM acceleration REFINES solver_var
        DIMENSION L/T^2
        DEFAULT 9.8{m/s^2};
        lower_bound := -1e50{m/s^2};
        upper_bound := 1e50{m/s^2};
        nominal := 9.8{m/s^2};
    END acceleration;

    ATOM frequency REFINES solver_var
        DIMENSION 1/T
        DEFAULT 60.0{1/s};
        lower_bound := 0.0{1/s};
        upper_bound := 1e50{1/s};
        nominal := 60.0{1/s};
    END frequency;

    ATOM stiffness REFINES solver_var
		DIMENSION M/T^2
		DEFAULT 1 {N/m};
		lower_bound := 0 {N/m};
		upper_bound := 1e12 {N/m};
		nominal := 1 {N/m};
	END stiffness;

		
(*  T R A N S P O R T   Q U A N T I T I E S
    ---------------------------------------  *)

    ATOM viscosity REFINES solver_var
        DIMENSION M/L/T
        DEFAULT 1.0{cP};
        lower_bound := 0.0{cP};
        upper_bound := 1e50{cP};
        nominal := 1.0{cP};
    END viscosity;

    ATOM thermal_conductivity REFINES solver_var
        DIMENSION M*L/T^3/TMP
        DEFAULT 0.1{BTU/hour/ft/R};
        lower_bound := 0.0{BTU/hour/ft/R};
        upper_bound := 1e50{BTU/hour/ft/R};
        nominal := 0.1{BTU/hour/ft/R};
    END thermal_conductivity;

    ATOM diffusivity REFINES solver_var
        DIMENSION L^2/T
        DEFAULT 1.0{cm^2/s};
        lower_bound := 0.0{cm^2/s};
        upper_bound := 1e50{cm^2/s};
        nominal := 1.0{cm^2/s};
    END diffusivity;


(*  E L E C T R O - M A G N E T I C  Q U A N T I T I E S
    ----------------------------------------------------  *)

    ATOM voltage REFINES solver_var
        DIMENSION M*L^2/(T^3*E)
        DEFAULT 10.0{volt};
        lower_bound := -1e50{volt};
        upper_bound := 1e50{volt};
        nominal := 10.0{volt};
    END voltage;

    ATOM resistance REFINES solver_var
        DIMENSION M*L^2/(E^2*T^3)
        DEFAULT 10.0{ohm};
        lower_bound := -1e50{ohm};
        upper_bound := 1e50{ohm};
        nominal := 10.0{ohm};
    END resistance;

    ATOM current REFINES solver_var
        DIMENSION E
        DEFAULT 1.0{amp};
        lower_bound := -1e50{amp};
        upper_bound := 1e50{amp};
        nominal := 1.0{amp};
    END current;

    ATOM capacitance REFINES solver_var
        DIMENSION E^2*T^4/M/L^2
        DEFAULT 1.0{coulomb/volt};
        lower_bound := -1e50{coulomb/volt};
        upper_bound := 1e50{coulomb/volt};
        nominal := 1.0{coulomb/volt};
    END capacitance;

    ATOM inductance REFINES solver_var
        DIMENSION M*L^2/E^2/T^2
        DEFAULT 1.0{volt*s/amp};
        lower_bound := -1e50{volt*s/amp};
        upper_bound := 1e50{volt*s/amp};
        nominal := 1.0{volt*s/amp};
    END inductance;

    ATOM magnetic_field REFINES solver_var
        DIMENSION E/L
        DEFAULT 1.0{amp/m};
        lower_bound := -1e50{amp/m};
        upper_bound := 1e50{amp/m};
        nominal := 1.0{amp/m};
    END magnetic_field;

    ATOM electric_field REFINES solver_var
        DIMENSION M*L/E/T^3
        DEFAULT 1.0{volt/m};
        lower_bound := -1e50{volt/m};
        upper_bound := 1e50{volt/m};
        nominal := 1.0{volt/m};
    END electric_field;

(*  D I F F E R E N T I A L  Q U A N T I T I E S
    -------------------------------------------  *)

    ATOM delta_distance REFINES solver_var
        DIMENSION L
        DEFAULT 10.0{ft};
        lower_bound := -1e50{ft};
        upper_bound := 1e50{ft};
        nominal := 10.0{ft};
    END delta_distance;

    ATOM temperature_rate REFINES solver_var
        DIMENSION TMP/T
        DEFAULT 0{K/s};
        lower_bound := -100{K/s};
        upper_bound := 100{K/s};
        nominal := 298.0{K/s};
    END temperature_rate;

    ATOM delta_mass REFINES solver_var
        DIMENSION M
        DEFAULT 0.0{kg};
        lower_bound := -1e50{kg};
        upper_bound := 1e50{kg};
        nominal := 10.0{kg};
    END delta_mass;

    ATOM delta_mole REFINES solver_var
        DIMENSION Q
        DEFAULT 0{lb_mole};
        lower_bound := -1e50{lb_mole};
        upper_bound := 1e50{lb_mole};
        nominal := 10.0{lb_mole};
    END delta_mole;

    ATOM delta_mass_rate REFINES solver_var
        DIMENSION M/T
        DEFAULT 0{g/s};
        lower_bound := -1e50{g/s};
        upper_bound := 1e50{g/s};
        nominal := 100.0{g/s};
    END delta_mass_rate;

    ATOM delta_molar_rate REFINES solver_var
        DIMENSION Q/T
        DEFAULT 0.0{lb_mole/hour};
        lower_bound := -1e50{lb_mole/hour};
        upper_bound := 1e50{lb_mole/hour};
        nominal := 100.0{lb_mole/hour};
    END delta_molar_rate;

    ATOM delta_volume_rate REFINES solver_var
        DIMENSION L^3/T
        DEFAULT 0.0{gpm};
        lower_bound := -1e50{gpm};
        upper_bound := 1e50{gpm};
        nominal := 100.0{gpm};
    END delta_volume_rate;

    ATOM density_rate REFINES solver_var
        DIMENSION M/L^3/T
        DEFAULT 0.0 {kg/m^3/s};
        lower_bound := -1e50 {kg/m^3/s};
        upper_bound := 1e50 {kg/m^3/s};
        nominal := 0.1 {kg/m^3/s};
    END density_rate;

    ATOM delta_energy_rate REFINES solver_var
        DIMENSION M*L^2/T^3
        DEFAULT 0.0{BTU/hour};
        lower_bound := -1e50{BTU/hour};
        upper_bound := 1e50{BTU/hour};
        nominal := 100000.0{BTU/hour};
    END delta_energy_rate;

    ATOM delta_molar_energy_rate REFINES solver_var
        DIMENSION M*L^2/T^3/Q
        DEFAULT 0 {BTU/lb_mole/h};
        lower_bound := -1e50 {BTU/lb_mole/h};
        upper_bound := 1e50 {BTU/lb_mole/h};
        nominal := 10000.0 {BTU/lb_mole/h};
    END delta_molar_energy_rate;

    ATOM delta_entropy_rate REFINES solver_var
        DIMENSION M*L^2/T^3/TMP
        DEFAULT 0.0{BTU/hour/R};
        lower_bound := -1e50{BTU/hour/R};
        upper_bound := 1e50{BTU/hour/R};
        nominal := 1000.0{BTU/hour/R};
    END delta_entropy_rate;

	
(*  C O N T R O L L E R  Q U A N T I T I E S
    ----------------------------------------  *)

    ATOM mass_sec REFINES solver_var
        DIMENSION M*T
        DEFAULT 0.0{kg*s};
        lower_bound := -1e50{kg*s};
        upper_bound := 1e50{kg*s};
        nominal := 10.0{kg*s};
    END mass_sec;

    ATOM mole_sec REFINES solver_var
        DIMENSION Q*T
        DEFAULT 0.0{lb_mole*s};
        lower_bound := -1e50{lb_mole*s};
        upper_bound := 1e50{lb_mole*s};
        nominal := 10.0{lb_mole*s};
    END mole_sec;

(*  D I F F E R E N T I A L S *)

	ATOM rate REFINES solver_var
		DIMENSION T^-1
		DEFAULT 0{s^-1};
		lower_bound := -1e50{s^-1};
		upper_bound := 1e50{s^-1};
		nominal := 1{s^-1};
	END rate;

(*  M E C H A N I C AL   P R O P E R T I E S
	---------------------------------------- *)
	
    ATOM deflection REFINES solver_var
        DIMENSION L
        DEFAULT 1 {mm};
        lower_bound := -10{m};
        upper_bound := 10{m};
        nominal := 5{mm};
    END deflection;

  	ATOM second_moment_of_area REFINES solver_var
  		DIMENSION L^4
  		DEFAULT 6.67e5 {mm^4}; (* for 150UB14 Universal Beam, AISC (Australia) *)
  		lower_bound := 0 {mm^4};
  		upper_bound := 10000e6 {mm^4};
  		nominal := 1e6 {mm^4}; (* this may be too high still *)
  	END second_moment_of_area;

    CONSTANT second_moment_of_area_constant
    REFINES real_constant DIMENSION L^4;
    
    CONSTANT length_constant
    REFINES real_constant DIMENSION L;

    CONSTANT area_constant
    REFINES real_constant DIMENSION L^2;
    
    ATOM moment REFINES solver_var
    	DIMENSION M*L^2/T^2
    	DEFAULT 1 {kN*m};
    	lower_bound := -1e5 {kN*m};
    	upper_bound := 1e5 {kN*m};
    	nominal := 1 {kN*m};
    END moment;
	
    ATOM stress REFINES solver_var
        DIMENSION M/L/T^2
        DEFAULT 1.0 {MPa};
        lower_bound := -5000 {MPa};
        upper_bound := 5000 {MPa};
        nominal := 1.0 {MPa};
    END stress;

	