Warka tower
(* Warka Water Tower, Mathematica by Oliver Knill, for multivariable exam *)
(* http://www.math.harvard.edu/~knill/teaching/summer2014/final/final.pdf *)
g1[t_] := 1.8 + Sin[t]; g[x_] := 0.4 g1[x];
S1 = ParametricPlot3D[{g[t] Cos[s + t/1.4], g[t] Sin[s + t/1.4], 2 t},
{t, 0.3, 2 Pi}, {s, 0, 2 Pi}, Mesh -> 20,
MeshStyle -> Brown, PlotStyle -> Opacity[0.0]];
S2 = ParametricPlot3D[{g[t] Cos[s - t/1.4], g[t] Sin[s - t/1.4], 2 t},
{t, 0.3, 2 Pi}, {s, 0, 2 Pi}, Mesh -> 20,
MeshStyle -> Brown, PlotStyle -> Opacity[0.0]];
S3 = ParametricPlot3D[ g[0.3] t {Cos[s], Sin[s], 0.3}, {s, 0, 2 Pi}, {t, 0, 1},
PlotStyle ->RGBColor[0.3,0.3,0], Mesh -> False];
h1[t_] := 1.1 + Sin[t - 0.6]/1.3; h[x_] := 0.4 h1[x];
S4 = ParametricPlot3D[{h[t] Cos[s], h[t] Sin[s], 0.5 + 1.5 t}, {t,
0.6, 2 Pi - 0.8}, {s, 0, 2 Pi}, Mesh -> False, PlotPoints -> 3,
PlotStyle -> {Specularity[White, 10], Yellow}];
S5 = VectorPlot3D[ {-y, x, 1}/2, {x, -1.5, 1.5}, {y, -1.5, 1.5}, {z, 1, 9},
VectorStyle -> "Arrow3D", VectorPoints -> 4,
VectorColorFunction -> "TemperatureMap",
VectorScale -> {0.2, Scaled[0.2]}];
Show[{S1, S2, S3, S4, S5},
PlotRange -> {{-2, 2}, {-2, 2}, {0, 10}}, Boxed -> False,
Axes -> False, AspectRatio -> 1]
From the article:
The invention from Arturo Vittori, an industrial designer, and his
colleague Andreas Vogler doesn't involve complicated gadgetry or feats
of engineering, but instead relies on basic elements like shape and
material and the ways in which they work together.
At first glance, the 30-foot-tall, vase-shaped towers, named after
a fig tree native to Ethiopia, have the look and feel of a showy art
installation. But every detail, from carefully-placed curves to unique
materials, has a functional purpose.
The rigid outer housing of each tower is comprised of lightweight and
elastic juncus stalks, woven in a pattern that offers stability in the
face of strong wind gusts while still allowing air to flow through. A
mesh net made of nylon or polypropylene, which calls to mind a large
Chinese lantern, hangs inside, collecting droplets of dew that form
along the surface. As cold air condenses, the droplets roll down into
a container at the bottom of the tower. The water in the container then
passes through a tube that functions as a faucet, carrying the water to
those waiting on the ground.
Using mesh to facilitate clean drinking water isn't an entirely new
concept. A few years back, an MIT student designed a fog-harvesting
device with the material. But Vittori's invention yields more water,
at a lower cost, than some other concepts that came before it.
"In Ethiopia, public infrastructures do not exist and building
[something like] a well is not easy," Vittori says of the country. "To
find water, you need to drill in the ground very deep, often as much
as 1,600 feet. So it's technically difficult and expensive. Moreover,
pumps need electricity to run as well as access to spare parts in case
the pump breaks down."
So how would Warka Water's low-tech design hold up in remote sub-Saharan
villages? Internal field tests have shown that one Warka Water tower
can supply more than 25 gallons of water throughout the course of a day,
Vittori claims. He says because the most important factor in collecting
condensation is the difference in temperature between nightfall and
daybreak, the towers are proving successful even in the desert, where
temperatures, in that time, can differ as much as 50 degrees Fahrenheit.
The structures, made from biodegradable materials, are easy to clean
and can be erected without mechanical tools in less than a week. Plus,
he says, "once locals have the necessary know-how, they will be able to
teach other villages and communities to build the Warka."
In all, it costs about 500 Dollars to set up a tower-less than a quarter of
the cost of something like the Gates toilet, which costs about ,200 to
install and more to maintain. If the tower is mass produced, the price
would be even lower, Vittori says. His team hopes to install two Warka
Towers in Ethiopia by next year and is currently searching for investors
who may be interested in scaling the water harvesting technology across
the region.
"It's not just illnesses that we're trying to address. Many Ethiopian
children from rural villages spend several hours every day to fetch water,
time they could invest for more productive activities and education," he
says. "If we can give people something that lets them be more independent,
they can free themselves from this cycle."
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