24:I[63208,["8920","static/chunks/8920-efbff8517d590b7e.js","9097","static/chunks/9097-7e60ff382fede0de.js","5914","static/chunks/5914-356082358a498a0b.js","9903","static/chunks/9903-11222066602aad8e.js","5438","static/chunks/5438-cfc6cd3ec63ed58c.js","3851","static/chunks/3851-d9d99b9df58ccefb.js","4621","static/chunks/4621-60797c2425663d2a.js","6871","static/chunks/6871-85cb03c97585f46a.js","6736","static/chunks/6736-932312a004c99faf.js","4550","static/chunks/4550-0bf059e3050c08b3.js","688","static/chunks/688-a6a2ac7bff269cd3.js","3984","static/chunks/3984-063c0b62f32133c7.js","7038","static/chunks/7038-4f87670d4e55ef18.js","9039","static/chunks/9039-75366c62dc7d0d0e.js","4563","static/chunks/4563-ad980d1babbf7b0b.js","6761","static/chunks/6761-0c10d1446de7ae1c.js","744","static/chunks/744-1e76229abb9e297b.js","7342","static/chunks/7342-1586df78600bf911.js","3617","static/chunks/3617-1f62a097637f4747.js","5895","static/chunks/5895-caa6c774914eb108.js","7481","static/chunks/7481-3b84c503a2ebfb3f.js","3668","static/chunks/3668-7dab69e4121c33af.js","39","static/chunks/39-e93a27d0920e6d92.js","2881","static/chunks/2881-445cc2384af2c6f9.js","2364","static/chunks/2364-e83d52fb21729d99.js","3208","static/chunks/3208-e65462d166bd3688.js","7582","static/chunks/app/toc/%5Btla%5D/%5Bvolume%5D/%5Bissue%5D/page-694a0e465c2c1334.js"],"default"] 25:T464,

A novel concept of using an expander to harvest atmospheric water is explored. The main advantages of this concept are its compactness and simplicity. Mathematical models were developed in this project to study the concept. The benchmark system had a crank and piston radii of 5 cm, rod length of 20 cm, operational speed of 60 rev/min, atmospheric temperature of 30°C and relative humidity of 80%. The expander was designed to expand the air to 0.7 bar and 0°C at the end of the expansion process. Because of the expansion, around 11.5 g of water was condensed for every 1 kg of air expanded. Most of the expander power was consumed during expansion to overcome the pressure difference across the two sides of the piston. The average power per cycle was 3.374 W. Therefore, the ratio of energy consumed and condensed water volume produced is 117 kWh/m³.

The parametric study found that the ratio of energy and water volume was unaffected by the operational speed, increased linearly as the ambient air was hotter, decreased with ambient relative humidity and was unaffected by the expander size.

26:T448,

Saiwa Swamp National Park in west-northern Kenya presents a typical wetland, and is habitat to the rare sitatunga antelope (Tragelaphus spekei). The swamp is surrounded by farms making it an ecological island, thus threatening the very existence of this wetland. Agrochemicals released from these farms are channelled into the swamp and thus affecting its physico-chemical status. This study compared the chemistry of water and soil sediments at specific sites along the swamp gradient during the rainy season. pH of surface waters was nearly neutral (mean of 7.0) during the entire study period while that of the soil sediments was acidic (4.6 to 5.0). Elements Ca, Mg and Fe recorded higher concentrations in dry season compared to the wet season. Other elements including Cu, Mn and Zn were not detected in surface water during the dry season. There was an increase in concentrations of Cu and Mn in the swamp waters during the wet season. The findings of the study showed a large percentage of the nutrients removed from the subsurface water in filtering contaminants.

27:T61b,