Aurel Lazar Spring Valley High School

1. Evaluating the water-collecting properties of various substrates in a low cost dew condenser for plant growth in simulated arid climate conditions Aurel Lazar Spring Valley High School

2. Deserts and Desertification • Natural process that creates deserts • Expansion of desert biomes • Deserts: • Receive small amounts of precipitation • Typically dry • Extreme diurnal temperature variation • Desertification only recently identified as worldwide phenomenon caused by the exponential increase in population

3. What is desertification? • The sporadic and completely random spread of a desert • A land degradation process that involves a continuum of change, from slight to very severe degradation of the plant and soil resource, and is due to man's activities (Dregne, 1986) • Mistakenly assumed to be an instant change to a sandy wasteland

4. Image taken by Serge Duchemin

5. Image from Public Domain, taken by Mike Chapman

6. Causes of Desertification • Usually natural, but recently, all major desertification is caused by humans (Dregne, 1986) • Global Warming • Land abuse after droughts (Watson) • Overgrazing • Salinization of land after irrigation • Cultivation of Marginal Land (Collins) • Removal of Vegetative Cover • Burning of Rainforests

7. Effects • 12 Million Hectares of land rendered deserts each year (Collins) • Degradation of Topsoils • Water run-off • Severe Floods in starting regions • Livestock death • Encroaching Sand Dunes • Dust Storms

8. Image Image produced by UNESCO

9. Vegetable Cover • Roots strengthen soil • Leaves soften fall of rain, reducing splash erosion • Less water run-off • Inhibits Salinization • Sustains water moisture • Necessary tool in countering desertification

10. Obtaining Water • Most people are unaware of the vast quantity of water available in airborne atmospheric rivers (Nelson, 2003) • Fog Fences – Must be on mountains • Desalinization Plants – Produce pollution (Alekseev et al., 1998) • Zibold Airwell – Large and bulky pile of rocks (Kogan et al., 2003) • Dew Collectors (Musseli et al., 2002)

11. Purpose • To create a low cost system for collecting water that can be used by all farmers to produce water in arid climates

12. Wire Condensate • Arid deserts have extremely high temperature ranges • 50°c in day • 0°c at night • Radiative Cooling of objects at night • Formation of dew (temperature difference must be extreme) • Creation of Wire Farms

13. Conceptual Wire Farm

14. Hypotheses • As the specific heat and density of the materials increases, the water yield will also increase • Non-metallic objects will work significantly better than metallic ones

15. Materials Aluminum Wire Steel Wire Plastic Wire Copper Wire Glass Wiring Environmental Chamber Pipettes Test Tubes Steel Tubing Glass Tubing Plastic Tubing Rubber Tubing Droppers Cork Stoppers Pliers

16. Wiring • Wires selected to take advantage of radiative cooling at night, allowing extreme temperature differences to produce condensation • Wiring would allow for mass extension, but thin lengths • Difficult for extension of brittle objects, such as glass

17. Wiring: Methodology Obtainment of Materials and Environmental Chamber Set-up of wiring Chamber set to run 3 full days with temperature variances from 40ºC to -5ºC Test tubes analyzed for water yields

18. Wiring: Experimental Design Diagram IV: Wire Material Copper Aluminum Plastic Steel Glass 6 Trials 6 Trials 6 Trials 6 Trials 6 Trials DV: Water Yield (mL) C: Humidity Regulated Temperature Testing Area Wire Volume (0.25 cm diameter x 0.5m length)

19. Wiring: Results and Discussion • No water yield collected for any of the groups • Condensate formed, but not enough to constitute a drop • Thickness of wires excessively small, allowing heating too quickly

20. Tubing • Due to the malfunctioning of wiring, an attempt to increase the specific heat of the substrates was needed • To do this, water was used as coolant in a series of pipes or tubes to keep the substrates cooler for longer periods of time • Whenever the outside of the tube began to heat up, the cold water would absorb the heat energy on the outside of the tube

21. Tubing: Methodology Filling of tubes with coolant (water) Sealing of tubes Chamber set to run for 24 hours Water quantified

22. Tubing: Experimental Design Diagram IV: Tubing Material Rubber Plastic Steel Glass 6 Trials 6 Trials 6 Trials 6 Trials DV: Water Yield (mL) C: Humidity Regulated Temperature Testing Area Tube Volume

23. Tubing: Results Water Yields of Various Materials Rubber Plastic Steel Glass 3.3 1.4 1.3 3.5 2.1 2.1 1.7 3.1 2.4 0.9 0.8 3.4 1.9 1.7 0.9 3.5 2.1 1.2 1.2 2.9 2.6 1.6 0.8 4.0

24. Tubing: Results

25. Tubing: ANOVA Test SS df MS F p-value Critical Value Between 18.763 3 6.2544 35.7737 3.13E-8 3.098 Within 3.496 20 0.1748 Total 22.259 23 H0: μrubber = μglass = μplastic = μsteel α = 0.05 F(3, 20) = 35.7737 > 3.098

26. Tubing: Tukey Test • μrubber≠ μglass • μrubber≠ μsteel • μrubber≠ μplastic • μglass≠ μplastic • μglass≠ μsteel • μsteel = μplastic

27. Tubing: Correlation Test

28. Tubing: Correlation Test Rubber Plastic Steel Glass N 6 6 6 6 Mean 2.400 1.483 1.117 3.400 StDev 0.506 0.417 0.354 0.379 S. H. (J/g°K) 1.6 1.12 0.438 0.84 H0: There is no correlation H1: There is a correlation between specific heat and mean water yield Critical r: 0.878Calculated r: 0.301 Because r < critical, H0 is accepted

29. Conclusions • Water can in fact be generated by such systems, albeit in small quantities. • Specific heat is not only determinant of water yield, disproving hypothesis • Glass and Rubber produced the most water in normalized settings

30. Realistic Applications • Energy inputs from sun to store electricity • Holed plastic tube with resistor running inside to generate temperature difference at night • Entire wire farms • Vibration system • Use of Fiberglass

32. Future Research • Heat sink of night sky in actual outdoor application • Actual desert environment • More optimized materials • Energy storing systems • Better coolants than water

33. Acknowledgements • Dr. Tammi Richardson at USC for aiding in the obtainment of an environmental chamber • My parents and teachers for their continuous support and encouragement

34. Literature Cited • Alekseev, V.V. and Berezkin, M.J. (1998). Fresh water from atmospheric vapour for arid regions. Renewable Energy Bulletin, 3, pp. 36–38 • Collins, J (2001, February 12). Desertification. Retrieved from VWC Enviro Facts Web site: http://www.botany.uwc.ac.za/Envfacts/facts/desertification.htm • Dregne, H. E. (1986). Desertification of arid lands. In Physics of desertification, ed. F. El-Baz and M. H. A. Hassan. Dordrecht, The Netherlands: Martinus, Nijhoff. • Kogan, B. et al. (2003). The moisture from the air as water resource in arid region: hopes, doubts and facts. Journal of Arid Environments, 53, pp. 231–240. • Muselli et al. (2002). Dew water collector for potable water in Ajaccio (Corsica Island, France). Atmospheric Research, 64, pp. 297–312 • Nelson, Robert A. (2003). Air wells: Methods for recovery of atmospheric humidity. Retrieved from Rex Research Web site: http://www.rexresearch.com/airwells/airwells.htm • Watson, K (1997). Desertification. Retrieved from Deserts: Geology and Resources Web site: http://pubs.usgs.gov/gip/deserts/

35. Evaluating the water-collecting properties of various substrates in a low cost dew condenser for plant growth in simulated arid climate conditions Aurel Lazar Spring Valley High School