strengths - many people can be tested quickly. It is easy to generate quantitative data and easy to analyse.
weakness - people may not tell the truth, especially on sensitive issues, for example, sexual behaviour.

strengths - detailed information can be obtained and avoids oversimplifying complex issues.
weakness - difficult to analyse if unstructured and qualitative in nature

survey (ii) - https://www.surveymonkey.com/r/7WWKZ8Y

- https://www.cdc.gov/safewater/solardisinfection.html

- https://www.osborneindustries.com/news/the-difference-between-thermoplastic-and-thermosetting-plastic/

- https://www.nobelprize.org/educational/chemistry/plastics/readmore.html

- http://time.com/4229503/plastic-in-microwave-is-it-safe/

- https://www.sswm.info/sswm-university-course/module-6-disaster-situations-planning-and-preparedness/further-resources-0/sodis

- https://www.goodnet.org/articles/1000

- https://water.org/about-us/our-work/

- http://water.columbia.edu

- https://waterislife.com

- http://www.puremadi.org/PureMadi/Welcome.html

- https://www.charitywater.org

- http://www.miya-water.com/en/

- https://www.threeavocados.org

- https://www.goodnet.org/articles/5-amazing-inventions-that-deliver-clean-water-videos

 

The solar disinfection tool will contain transparent water bottles made out of Polyethylene terephthalate

such as the plastic bottles in which soft drink beverages are soldthat are filled with water from any contaminated sources. The bottles will be placed on a stand that will be created accordingly to its exposure to the sun as that is how the solar energy will be used to purify the water. The treatment efficiency will be better if the plastic bottles are placed on sunlight reflecting surfaces, such as corrugated aluminum or zinc roofs. This can increase the water temperature by about 5°C and allow the purification process to happen a lot faster.

If the water bottles are not exposed to sunlight for the proper length of time, the water may not be safe to drink and could cause illness. After treatment, the water can be consumed. Apart from the practicality, the product will also be aesthetically pleasing and appealing to the consumers as it will incorporate minimalist features and a mix of colours that go together. The materials used would be plastic for sure and in addition to that, either wood or bamboo could be used for the stand of the product. My designed devices may need human intervention such as regular maintenance. If specific designs need human intervention, I will make sure to make the product user friendly and if the use of the product is complex, I will also design and create a manual for the solution to ensure it being used correctly. While they will accompany many design features, I will make sure to minimise the production cost that will be spent while manufacturing of the device. I will try to limit the production cost to about Rs. 500 and if it exceeds, I will explain and justify cheaper alternatives that will be able to replace the existing mechanism which I used and reduce the total fixed cost of the product.Furthermore, there has been some concern over the question whether plastic drinking containers can release chemicals or toxic components into water, a process possibly accelerated by heat. Although, recent research studies have examined different types of plastic in the water during solar exposure. The levels of concentrations found in the water after a solar exposure of 17 hours in 60°C water were far below the guidelines for drinking water and in the same magnitude as the concentrations of phthalate and adipate generally found in high quality tap water. Hence, the plastic bottles and materials are safe to be used.

 

In conclusion, the product is a part of sustaining the environment against a man- made calamity; hence it is also important that the product promotes, campaigns or advertises water conservation and environmental sustainment.