## 3 Results and Discussion  
A series of experiments were performed to find the effect of magnetism on heat conduction in the lanthanum nickel bed. In these experiments, magnet 1 was placed at the bottom of the reactor and temperature was measured at thermocouples 1 and 5, which are at the center of the reactor and on its wall, respectively (Table 2). In these experiments, in order to estimate the improved thermal conductivity of the bed, no hydrogenation was performed. The improvement in thermal conductivity is calculated using the formula derived from [PERSON]'s law of heat conduction under steady state conditions [42]:  
\[\frac{k_{\mathit{with\ magnet}}}{k_{\mathit{without\ magnet}}}=\frac{(T_{5}-T_{1})_{ \mathit{without\ magnet}}}{(T_{5}-T_{1})_{\mathit{with\ magnet}}}\]  
where \(T_{1}\) and \(T_{5}\) are the temperatures of thermocouples at the center of the reactor and at the wall, respectively, and the temperature values were used once steady state is reached. When magnet 1 is used, the results showed around 8-9% improvement in the thermal conductivity of bed. The error margin of the thermocouples used in this work is 1-2.5% for temperatures below 973 K. Temperatures at the center of the reactor and its wall with and without magnet 1 are depicted in Figure 5. It can be observed that the steady state was reached quickly when the magnet was used, indicating a faster heat transfer rate. It can also be observed from the figure that the maximum temperature is lower inside the  
Figure 4: Hydrogen storage setup and its schematic diagram showing the components. metal hydride tank (\(T_{1}\)) and on the reactor wall (\(T_{5}\)) when the magnetic field is applied. This shows that using the magnetic field can enhance the heat transfer in metal hydride beds. Considering that experimental results supported heat transfer enhancement in the LaNi\({}_{5}\) bed under magnetism, a set of experiments were run to check the hydrogen absorption properties of lanthanum nickel under magnetism. In these experiments, magnets 1 and 2 are used to provide magnetic fields inside the reactor. Initially, experiments were done to check the amount of hydrogen absorption in the bed without any magnetic fields, and then two series of experiments with magnets 1 and 2 were performed. Temperature distributions of two sample experiments during the hydriding process inside the reactor and on its wall are illustrated in Figure 6.  
Figure 5: Temperature measurements of the reactor (Top) and wall (Bottom) with and without magnet in LaNi\({}_{5}\) bed during heat conduction experiments. Steady state is reached faster when magnet is present. Few conclusions can be drawn from Figure 6. From the temperature measurement inside the metal hydride reactor, it is seen that the maximum temperature is recorded as soon as hydrogenation initiated. Also, the temperature peak increases with increased magnetic flux. Considering that the heat source in these experiments is the released heat through exothermic hydrogen absorption reaction, it is concluded that the higher magnetic intensity enhances the rate at which the reaction takes place. Figure 6: Temperature measurement inside reactor (**Top**) and on its wall (**Bottom**) during hydrogenation. In other words, the reaction kinetics are enhanced under the effect of the magnetic fields. Though the difference in temperatures under three cases is not significant before the reaction initiates, the difference in temperatures is more prominent during and after the reaction. This is due to the high energy released during the reaction and the dissipation of heat at different thermal conductivities in all the three cases. Measured pressures in the reactor and reservoir are presented in Figure 7. From the final pressures in the reactor as shown in Figure 7, at the end of data recording time the equilibrium pressure of reaction experiences a slight increase.