This model illustrates predator prey interactions using real-life data of bison and wolf populations at Yellowstone National Park.
Yellowstone Bison & Wolf Model
HarperCollins - Supply Chain Group Verweij,
This model prototypes the working of an Smart Grid with Electric Vehicles
The objective is testing the theoretical advantages of batteries (also batteries in Electric Vehicles) in combination with renewable energies. The model considers two houses, that store energy both in Electric Vehicles (Vehicle to Grid), and in a communal battery.
Except when specified otherwise, the units of all variables are expressed in W/h.
Press "Story" in the lower bar for a guided tour over the model. Better seen at 50% zoom.
by Carlos Varela (cvarela@gmx.at)
Clone of Vehicle to Smart Grid - Prototype
Simple model to illustrate Steele's equation for primary production of phytoplankton.
The equation is:
Ppot = Pmax I/Iopt exp(1-I/Iopt)
Where:
Ppot: Potential production (e.g. d-1, or mg C m-2 d-1)
Pmax: Maximum production (same units as Ppot)
I: Light energy at depth of interest (e.g. uE m-2 s-1)
Iopt: Light energy at which Pmax occurs (same units as I)
The model contains no state variables, just illustrates the rate of production, by making the value of I equal to the timestep (in days). Move the slider to the left for more pronounced photoinhibition, to the right for photosaturation.
Clone of Phyto 1 - PI curve for phytoplankton
Simple model to illustrate Steele's equation for primary production of phytoplankton.
The equation is:
Ppot = Pmax I/Iopt exp(1-I/Iopt)
Where:
Ppot: Potential production (e.g. d-1, or mg C m-2 d-1)
Pmax: Maximum production (same units as Ppot)
I: Light energy at depth of interest (e.g. uE m-2 s-1)
Iopt: Light energy at which Pmax occurs (same units as I)
The model contains no state variables, just illustrates the rate of production, by making the value of I equal to the timestep (in days). Move the slider to the left for more pronounced photoinhibition, to the right for photosaturation.
Clone of Clone of Phyto 1 - PI curve for phytoplankton
Simple model to illustrate Michaelis-Menten equation for nutrient uptake by phytoplankton.
The equation is:
P = Ppot S / (Ks + S)
Where:
P: Nutrient-limited production (e.g. d-1, or mg C m-2 d-1)
Ppot: Potential production (same units as P)
S: Nutrient concentation (e.g. umol N L-1)
Ks: Half saturation constant for nutrient (same units as S)
The model contains no state variables, just illustrates the rate of production, by making the value of S equal to the timestep (in days). Move the slider to the left for more pronounced hyperbolic response, to the right for linear response.
Clone of Phyto 2 - Michaelis-Menten curve for phytoplankton
Simple modern carbon cycle model for use in virtual education modules.
Carbon Cycle
Units don't really work, not sure what to do regarding flow units (can't divide units and the conversion part doesn't make any sense)
Revenue Model from Savings
Solution of Recycling Problem in Vancouver
This model is a classic simulation of the production cycle in the ocean, including the effects of the thermocline in switching off advection of dissolved nutrients and detritus to the surface layer.
It illustrates a number of interesting features including the coupling of three state variables in a closed cycle, the use of time to control the duration of advection, and the modulus function for cycling annual temperature data over multiple years.
The model state variables are expressed in nitrogen units (mg N m-3), and the calibration is based on:
Baliño, B.M. 1996. Eutrophication of the North Sea, 1980-1990: An evaluation of anthropogenic nutrient inputs using a 2D phytoplankton production model. Dr. scient. thesis, University of Bergen.
Fransz, H.G. & Verhagen, J.H.G. 1985. Modelling Research on the Production Cycle of Phytoplankton in the Southern Bight of the Northn Sea in Relation to Riverborne Nutrient Loads. Netherlands Journal of Sea Research 19 (3/4): 241-250.
This model was first implemented in PowerSim some years ago by one of my M.Sc. students, who then went on to become a Buddhist monk. Although this is a very Zen model, as far as I'm aware, the two facts are unrelated.
Clone of NPD model (Nutrients, Phytoplankton, Detritus)
for more information, contact Dr. Ann Stapleton at: stapletona@uncw.edu
Description:
A simple model for breeding plants from generation to generation, with one "yield" variable (e.g. height) and 4 combinations of plants from the parents. Simulation tracks the frequencies of each combination in each generation as well as the overall average height by generation.
Adjust all sliders before beginning simulation. Make sure the A1A2 parameters are equal to the A2A1 parameters.
Plant Breeding Simulation
In Chile,
60% of its population are exposed to levels of Particulate Matter (PM) above international standards. Air Pollution is causing
4,000 premature deaths per year, including health costs over US$8 billion.
The System Dynamics Causal Loop Diagram developed herein shows an initial study of the dynamics among the variables that influences the accumulation of PM in the air, in particular the case of Temuco, in the South of Chile. In Temuco, 97% of the PM inventories comes from the combustion of low quality firewood, which in turns is being burned due to its low price and cultural habits/tradition.
Clone of Clone of Air Pollution Dynamics - Firewood Combustion
Simple model to illustrate oyster growth based on primary production of Phytoplankton as a state variable, forced by light and nutrients, running for a yearly period.
Phytoplankton growth based on on Steele's and Michaelis-Menten equations), where:
Primary Production=(([Pmax]*[I]/[Iopt]*exp(1-[I]/[Iopt])*[S])/([Ks]+[S]))
Pmax: Maximum production (d-1)
I: Light energy at depth of interest (uE m-2 s-1)
Iopt: Light energy at which Pmax occurs (uE m-2 s-1)
S: Nutrient concentration (umol N L-1)
Ks: Half saturation constant for nutrient (umol N L-1).
Further developments:
- Nutrients as state variable in cycle with detritus from phytoplankton and oyster biomass.
- Light limited by the concentration of phytoplankton.
- Temperature effect on phytoplankton and Oyster growth.
Clone of Clone of micro algae , biogas , bioelectrcidades
Carbon Model for sustainability
In Chile,
60% of its population are exposed to levels of Particulate Matter (PM) above international standards. Air Pollution is causing
4,000 premature deaths per year, including health costs over US$8 billion.
The System Dynamics Causal Loop Diagram developed herein shows an initial study of the dynamics among the variables that influences the accumulation of PM in the air, in particular the case of Temuco, in the South of Chile. In Temuco, 97% of the PM inventories comes from the combustion of low quality firewood, which in turns is being burned due to its low price and cultural habits/tradition.
Clone of Air Pollution Dynamics - Firewood Combustion
In Chile,
60% of its population are exposed to levels of Particulate Matter (PM) above international standards. Air Pollution is causing
4,000 premature deaths per year, including health costs over US$8 billion.
The System Dynamics Causal Loop Diagram developed herein shows an initial study of the dynamics among the variables that influences the accumulation of PM in the air, in particular the case of Temuco, in the South of Chile. In Temuco, 97% of the PM inventories comes from the combustion of low quality firewood, which in turns is being burned due to its low price and cultural habits/tradition.
Clone of Clone of Clone of Air Pollution Dynamics - Firewood Combustion
all pictures sourced from google images
Tundra Food Web
This is to support a discussion on money flows and growth. Money as a lubricant for the flow of embodied energy in human systems.
See also A Prosperous Way Down website
Odum Money and Energy Flows
A storytelling of the nitrogen cycle.
Met Nederlandse teksten
Nitrogen Cycle - Nederlands
In Chile,
60% of its population are exposed to levels of Particulate Matter (PM) above international standards. Air Pollution is causing
4,000 premature deaths per year, including health costs over US$8 billion.
The System Dynamics Causal Loop Diagram developed herein shows an initial study of the dynamics among the variables that influences the accumulation of PM in the air, in particular the case of Temuco, in the South of Chile. In Temuco, 97% of the PM inventories comes from the combustion of low quality firewood, which in turns is being burned due to its low price and cultural habits/tradition.
Clone of Air Pollution Dynamics - Firewood Combustion
This model adresses the primary production for phytoplankton growth, based on Steele’s light intensity equation and Michaelis-Menten equation for nutrient limitation.
Primary production of phytoplankton (SIMA2018_G1)
The Grate Barrier Reef Food Chain
Primitives for Watershed modeling project. Click Clone Insight at the top right to make a copy that you can edit.
The converter in this file contains precipitation for Phoenix only.
Primitives for Rainwater Harvesting -Phoenix ENVS 270 F21
HANDY Model of Societal Collapse from Ecological Economics
Paper see also D Cunha's model at IM-15085 (Spanish)
Human and Nature Dynamics of Societal Inequality
