**4.3 FEMM simulation**

FEMM can be simulated with some software. In general, all simulation procedures in some software are almost the same, such as FEMM and Ansoft Maxwell. The simulation process starts by making a design that will be simulated in a twodimensional sketch. However, to perform a FEMM simulation, in general, the design to be simulated is made in two dimensions. Next is the material selection stage, coil configuration, meshing, and simulating as described below:


**5.7 Maintenance of cultures**

The media should be replaced weekly; it is not necessary if massive media (100 L) is used. Approximately 30 Daphnias per culture should be selected every week; to retrieve them a glass or plastic Pasteur pipette must be used. This activity is suggested to do at the same time when the medium is changed, this system will avoid cross-linking (American Public Health Association, 2002).

### **5.8 Selection of organisms for test**

The examination should initiate with the second or third offspring, selecting neonates with ≤ 24 birth hours. Before the initiation any test, 30 to 40 young Daphnias should be isolated on a 400 mL beaker with 300 mL of algae mix (*Ankistrodesmus falcatus, Selenastrun capricornutum,* and *Clorella*). Do not use ephippiums for Daphnia cultures, because its presence is an indicator of unfavorable conditions (American Public Health Association, 2002).