MFA 3

Question 1

what is the definition of MFA ?

Answer 1

il comprend un ensemble de flows, stock and process defined within a precise boundary : SPACE and TIME

Question 2

what are the type of boundaries of an evaluated MFA?

Answer 2

1)system boundary (space and time)
2)temporal boundary = time period which over the material balance is calculated
3)spatial boundary geographical area

Question 3

what is the definition of a process ?

Answer 3

any kind of transformation, transport or storage of a material that is characterized with input or output flows

Question 4

in the system you have the materials, what are the 2 components ? + give their definition

Answer 4

a material is composed of goods and substances. a substance chemical element (carbon) or compound (carbon dioxide = composition) of unit element.
a good is actually a substance but with monetary value (economic value that can be positive or negative)

Question 5

give (4 out of 7) example of processes

Answer 5

-waste incineration process
-wastewater treatment plant
-energy production process
-recycling process
-human physiological process
-landfill
-gas lank farm (??)

Question 6

what is the definition of a stock ? name the 2 different type of stocks

Answer 6

material réservoir or material quantité whitin a process (can be constant/increase/decrease size)
accumulation / depletion of stocks: nommé pr dire que ça se remplit pou ça se vide
1)geogenic stocks : nature
2)anthropogenic stocks : lié a l’humain

Question 7

what is a flow?

Answer 7

une fleche qui relie un process a un autre ! un process c est que qui transforme la matière, qui se déplace en stock, et la matière est faite de substance et de gonds
=ratio mass per time

Question 8

fluxes def?

Answer 8

flow per cross section (maison privée)

Question 9

what are input output flows?

Answer 9

intering / exiting a process (mais tjr dans le systèmes),
=>relatif a un process

Question 10

what are import / exports?

Answer 10

flow across system boundaries
=>relatif a un système

Question 12

time / flows : what is a steady state?

Answer 12

constant flows and stocks
(la dérivée de la quitté de stock est nulle => c’est une constante lol)

Question 13

what is quasi stationary state?

Answer 13

constant flow and linear (de)growth of stock (la derived est eagle a une cste)

Question 14

what is time dependent ?

Answer 14

external parameters of the model are function of time

Question 15

dynamic state ?

Answer 15

system state that is at t is the function of the state tl1 (chaque état depend du precedent, corrélé)