## 3 Results and Discussion  
Solar irradiance is directly related to the ambient temperature of the environment. Solar irradiance is affected by wind speed and the values will be recorded with a lower value than the corresponding ambient temperature. The solar irradiance values were recorded on day 1 (with a 0.5 cm-thick banana stem) from 585 W/m\({}^{2}\) at 10:00 a.m. to 89 W/m\({}^{2}\) in the evening at 17:00 p.m. with a peak value at 12:00 p.m. as 800 W/m\({}^{2}\). On day 2 (with a 1.0 cm-thick banana stem), the values ranged from 570 W/m\({}^{2}\) at 10:00 a.m. to 60 W/m\({}^{2}\) at 17:00 p.m., and at noon, the peak value of the day was achieved as 785 W/m\({}^{2}\). On day 3 (with a 1.5 cm-thick banana stem), the values were recorded as 516 W/m\({}^{2}\) at 10:00 a.m., 754 W/m\({}^{2}\) at 12:00 p.m., and 110 W/m\({}^{2}\) at 17:00 p.m. Similarly, the ambient temperature was 22-25 \({}^{\circ}\)C at 9:00 a.m. and reached a high of 30-33 \({}^{\circ}\)C around mid-day for all three days. On all of the days, the solar irradiance showed little variation, which concludes that all of the days had the same solar intensity conditions with minimal variation which was just negligible. The solar irradiance and ambient temperature variation for all three days are depicted in Figure 3.  
Using three distinct thermocouples, the temperatures of the water (T\({}_{\rm w}\)), glass (T\({}_{\rm g}\)), and basin (T\({}_{\rm b}\)) were monitored and are graphically depicted in Figure 4a-c. For the modified still, the maximum water temperatures were obtained at 61 \({}^{\circ}\)C, 58 \({}^{\circ}\)C, and 59 \({}^{\circ}\)C for the 0.5 cm-, 1.0 cm-, and 1.5 cm-thick banana stems, respectively. For the conventional still, the highest water temperatures were 56 \({}^{\circ}\)C, 54 \({}^{\circ}\)C, and 55 \({}^{\circ}\)C for all three consecutive days, respectively. Due to the presence of camphor-soothed banana stems, the temperatures of the water readings between the CSS and the MSS deviate from one another. More solar energy is absorbed by the banana stems in the solar basin, which leads to heat localization and transfers a significant amount of the energy flux from the sun to the water available on the surface of the banana stems. For the modified still with the 0.5 cm-, 1.0 cm-, and 1.5 cm-thick banana stems, the highest basin temperatures were 60 \({}^{\circ}\)C, 59 \({}^{\circ}\)C, and 57 \({}^{\circ}\)C, respectively, while for the conventional still, they were 57 \({}^{\circ}\)C, 58 \({}^{\circ}\)C, and 56 \({}^{\circ}\)C, respectively. This is owing to the energy interactions that occurred between the basin of the solar stills and the camphor-soothed banana stems. A maximum distillate yield was achieved by the improved evaporation rates, which were aided by the aforementioned water and basin temperatures. For the modified still, the highest glass interior temperatures were 54 \({}^{\circ}\)C for the 0.5 cm-, 55 \({}^{\circ}\)C for the 1.0 cm-, and 56 \({}^{\circ}\)C for the 1.5 cm-thick banana stems. The maximum glass interior temperatures for the conventional still were 52 \({}^{\circ}\)C, 54 \({}^{\circ}\)C, and 53 \({}^{\circ}\)C, respectively. Moreover, the evaporation of rate of saline water depends on the difference in temperature (T\({}_{\rm w-g}\)) between the water (T\({}_{\rm w}\)) and the glass (T\({}_{\rm g}\)). As this difference in temperature increases, the evaporation rate will also increase. This difference in the case of 0.5 cm and 1.0 cm was about 7 \({}^{\circ}\)C and 3 \({}^{\circ}\)C, respectively, in the MSS at the peak time. For the present study, the camphor-soothed stems absorbed the incoming solar energy and transferred it to the water surrounding them. As a result, the water temperatures are higher when compared to the basin temperatures in the MSS, whereas in the CSS, the basin temperatures are more in contrast to the water temperatures. For all three consecutive days,