what's the number of times the letter "d" appears in:
about 880 million people don’t have access to clean potable water. a head-stander beetle’s carapace could produce relief. scientists are taking him as an example for water harvesting in extremely arid areas.
the world water report of unesco paints a sinister picture of drinking water. climate change, strong growth of the population and the resulting increasing demand of food and energy make the vital element run scarce in many regions of the world. today already, one eighth of the world’s population suffers from lack of drinking water. even local agriculture lacks necessary water supply in many places. . a global problem tackled by engineers thomas stegmeier and jamal sarsour from denkendorf’s institute for textile and fibre research (itv). in cooperation with geo-scientists of tübingen university, the researchers developed a three-dimensional fog catcher, which is supposed to supply even extremely arid areas with water. a little head-stander beetle served as an example to the bionic experts’ invention. the scientists of itv took advantage of its principle: they developed a three-dimensional spacer fabric with loop stitches resembling the structure of the carapace. this spacer fabric can collect aerosols from the air and drains them.
in cooperation with claim for dignity, melanchthon high school bretten, denkendorf institute for textile and fibre research and schools in poor districts water is collected from fog and dew in prototypes and then analysed. basic principles for alternative technologies for watering plants and drinking water abstraction are worked out.
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The text includes fifty-one "d"s in total.
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