H.E.L.P. Heart Empowers Lifelong Pacemaker
EXPERIMENT 1---The effect of NaCl and Glucose Concentration on the efficiency of the cell I. Introduction Experiment on different concentrations of standard glucose solution (ranged from 0.125 M to 1.000 M) and standard sodium chloride solution (ranged from 0.250 M to 4.000 M) were done. We investigated the full concentration effect, which included both concentration of glucose solution and sodium chloride solution on the fuel cell’s output voltage, current and power. II. Procedures 1. Add 25.0 cm3 of Glucose solution of the tested concentration to the beaker representing the anode, and add 25.0 cm3 of distilled water to the beaker representing the cathode. 2. Add 50.0 cm3 of 0.250 M NaCl (aq) to both beakers representatively. 3. Fold a piece of filter paper and soak in fully into NaCl (aq) at cathode. 4. Clean and place the silver wires into the beakers representatively, and connect the air pump to the cathode. 5. Connect the cell to two multi-meters, each acting as a voltmeter and an ammeter respectively 6. Take the readings of multi-meters after 30 seconds. 7. Repeat steps 1 to 6 twice for the second and third reading of the cell. 8. Take average value among three values as the final reading of the cell. 9. Repeat steps 1 to 8 by replacing the NaCl (aq) with concentrations of 0.000 M, 0.500 M, 1.000 M, 2.000 M and 4.000 M, and the standard glucose solution with concentrations of 0.000 M, 0.125 M, 0.250 M, 0.500 M, 0.750 M and 1.000 M. III. Result of Experiment 1 When glucose concentration is increased from 0.000 M to 0.250 M, the output power increases, it is found that power generated is maximized at glucose concentrations between 0.125 M and 0.250 M. However, with further increase in glucose concentration from 0.250 M to 1.000 M, the power generated decreases. This shows that high concentration of glucose inhibits the generation of electricity, while higher concentration of sodium chloride solution can increase the output. EXPERIMENT 2---The effect of temperature on the efficiency of the cell I. Introduction In this experiment, the second effect - temperature on the fuel cell’s output voltage, current and power was investigated. In order to get a significant result, the effect of temperature on these measures with fixed 0.250 M glucose solution and sodium chloride solution concentrations varied from 0.500 M to 4.000 M had been investigated. II. Procedures 1. Add 25.0 cm3 of Glucose solution of the tested concentration (0.25 M) to the beaker representing the anode, and add 25.0 cm3 of distilled water to the beaker representing the cathode. 2. Add 50.0 cm3 of 0.500 M NaCl (aq) to both beakers representatively. 3. Fold a piece of filter paper and soak in fully into NaCl (aq) at cathode. 4. Clean and place the silver wires into the beakers respectively, and connect the air pump to the cathode. 5. Connect the cell to two multi-meters, each acting as a voltmeter and an ammeter respectively 6. Take the readings of multi-meters after 30 seconds. 7. Repeat steps 1 to 6 twice for the second and third reading of the cell. 8. Take average value among three values as the final reading of the cell. 9. Repeat steps 1 to 8 by varying the temperature from 42℃ to 32℃. 10. Repeat steps 1 to 9 by replacing the NaCl solution of 0.000 M, 1.000 M, 2.000 M, and 4.000 M respectively. III. Result of Experiment 2 The results showed a consistent trend and relationship of the effect of temperature on the output current, voltage and power of the fuel cell for 4 different concentrations of sodium chloride solution with fixed 0.25 M glucose solution. Generally, the results showed that the output power increases with temperature. EXPERIMENT 3---The effect of dialysis tubing and Nafion 117 on the efficiency of the cell I. Introduction Semi-permeable membrane separating glucose and oxygen, ensure the glucose oxidation only occurs at the anode, and preventing glucose oxidation occurs at the cathode, responds to maximize power output. Experimental study on two kinds of membranes, dialysis membranes and Nafion 117 films were done, by studying their fuel cell output voltage, current and power effects. Previous experiments showed that the optimal output of the battery is at 0.250 M glucose solution, Therefore, experimental conditions for glucose concentration is fixed on 0.250 M and sodium chloride solution concentration varies from 0.500 to 4.000 M. II. Procedures The Effect of Dialysis Tubing on voltage and current of the fuel cell 1. Pour 50 cm3 1.000 M NaCl (aq) to each compartment of the beaker separated by dialysis tubing. 2. Pour 0.250 M Glucose Solution into the compartment representing anode. 3. Connect the cell to two multimeters, which act as a voltmeter and ammeter respectively 4. Take the reading of the multimeters after 30 seconds 5. Repeat steps 1 to 4 twice for the second and third reading of the cell. 6. Take average value among three values as the final reading of the cell. 7. Repeat steps 1 to 6 with NaCl (aq) with concentration of 0.000 M, 0.250 M, 0.500 M, 2.000 M and 4.000 M to obtain the remaining data. The Effect of Nafion 117 on voltage and current of the fuel cell 1. Add 50 cm3 1.000 M NaCl (aq) and 50 cm3 of 0.250 M of glucose solution to the beaker. 2. Add 1.000 M NaCl (aq) to the Nafion 117 membrane pouch, and silver plate was put inside to become the anode. 3. Connect the cell to two multimeters, which act as a voltmeter and ammeter respectively 4. Take the reading of the multimeters after 30 seconds 5. Repeat steps 1 to 4 twice for the second and third reading of the cell. 6. Take average value among three values as the final reading of the cell. 7. Repeat steps 1 to 6 with NaCl (aq) with concentration of 0.000 M, 0.250 M, 0.500 M, 2.000 M and 4.000 M to obtain the remaining data. III. Result of Experiment 3 The result had shown that when the solution does not contain glucose (i.e. Glucose concentration equals to 0.000 M), Nafion 117 Membrane Cells have similar power outputs compared to the dialysis tubing cells. However, in 0.250 M glucose solution, the output of Nafion 117 membrane cell is about 1 to 5 times more compared to that of dialysis tubing cell. According to the experiment results, it was found out that the power output was maximized when the concentration of glucose solution and NaCl (aq) are 0.250 M and 4.000 M respectively. Under this concentration, the out of Nafion 117 membrane cell was 1336.68 nW which was 5 times higher than that of dialysis tubing cell. Hence, adopting Nafion 117 as the selectively membrane can greatly enhance the output of cell. It is believed that the special structure of Nafion 117 has limited the movement of glucose molecules, and prevented their oxidation at cathode. This has enhanced the oxidation of glucose at anode, and thus increased the power output of the cell.
Findings of new oscillations in BR reaction
The Briggs Rauscher reaction, i. e., BR reaction, which is one of the oscillation reactions, produces iodide ion and iodine repeatedly. Continual color changes of the solution from colorless to deep blue, and vice versa, are observed during the reaction due to the so-called “iodine test” reaction. In this work, we studied the effects of the presence of the redox active indicators on the oscillation behavior of the BR reaction. To the reaction mixture of KIO3, H2SO4, H2O2, C3H4O4, MnSO4, and starch, which are used for the general BR reaction as added a redox active reagent (indicator). Then, the changes in color and voltage of the reaction solution were recorded by a photosensor of the LEGO MINDSTORMS and a voltmeter using Pt electrodes. Under general reaction conditions, the oscillation reaction continued for ca. 5 minutes, including 18 times of oscillations. When an indicator, such as BTB, was added instead of starch to the reaction solution, splits of the voltage wave were observed, which should be a kind of new oscillation. Moreover, we found that the addition of K3[Fe(CN)6], which exhibits high redox activity, in the reaction solution instead of starch made the life-time and the numbers of the oscillation in the reaction greater by 3 times (14 min.) in time and more than 4 times (81 times) in the frequency. It’s also a kind of new oscillation. These results suggested that the oxidation-reduction reactions by the addition of ferricyanate ion effectively promotes the redox process of iodine and iodide ion. The experiments we wrote above were conducted without starch. Thus, as a reference, we conducted the same experiments under the presence of starch and got interesting results. We also studied the effects of K4[Fe(CN)6], suggeting that not only redox reaction between ferricyanide and ferrocyanide ion, but also the redox reaction with BR solution should occur in these reactions.