# Team:Cambridge/Tools/Lighting

(Difference between revisions)
 Revision as of 16:02, 26 October 2010 (view source)Theos (Talk | contribs) (→Putting it into practice)← Older edit Revision as of 16:44, 26 October 2010 (view source)Willh (Talk | contribs) Newer edit → Line 3: Line 3: We had a number of workshops considering the potential broader societal implications of our work.  Given the energy crisis facing our planet, lighting, which accounts for 8% of our use of electricity, seemed an interesting application of our work. We had a number of workshops considering the potential broader societal implications of our work.  Given the energy crisis facing our planet, lighting, which accounts for 8% of our use of electricity, seemed an interesting application of our work. =Bioluminescent street lamps= =Bioluminescent street lamps= - {{:Team:Cambridge/Templates/RightImage|image=Cambridge-City.jpg|caption=We created a 3D model to try to visualise a city lit by bioluminescent trees}} + {{:Team:Cambridge/Templates/RightImage|image=Cambridge-City.jpg|caption=''We created a 3D model to try to visualise a city lit by bioluminescent trees''}} In order to provide any solution to the problem, a biological solution must tap into a currently unused energy resource.  For this reason we decided to consider the use of '''bioluminescent trees''' to replace conventional street lamps. In order to provide any solution to the problem, a biological solution must tap into a currently unused energy resource.  For this reason we decided to consider the use of '''bioluminescent trees''' to replace conventional street lamps. Line 11: Line 11: =Putting it into practice= =Putting it into practice= - {{:Team:Cambridge/Templates/RightImage|image=Jungle_book.jpg|caption=Ben proving it is possible to read by bioluminescent light}} + {{:Team:Cambridge/Templates/RightImage|image=Jungle_book.jpg|caption=''Ben proving it is possible to read by bioluminescent light''}} We wanted to provide some proof of concept of these ideas.  We built the [http://www.youtube.com/watch?v=tUFscEVK5Ks bacterial bubble lamp] to investigate this, and also read the Jungle Book using a flask containing E. coli expressing our bacterial luciferase. We wanted to provide some proof of concept of these ideas.  We built the [http://www.youtube.com/watch?v=tUFscEVK5Ks bacterial bubble lamp] to investigate this, and also read the Jungle Book using a flask containing E. coli expressing our bacterial luciferase. - - We had thought about bacteria being used for emergency lighting, and our advisor Fernan printed a fire exit sign, which was placed over a plate containing one of our strains of E. coli.  In a real system we would imagine using anhydrobiosis to create bacteria 'in hibernation' which could be activated when needed. - -
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Our LuxBrick with an overlay to give a meaningful message
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- =Modelling= =Modelling= Line 26: Line 18: {{:Team:Cambridge/Templates/RightImage|image=Fischerispectrum.jpg|caption=''Figure 2: The emission spectrum of V. Fischeri (shown in black)''}} {{:Team:Cambridge/Templates/RightImage|image=Fischerispectrum.jpg|caption=''Figure 2: The emission spectrum of V. Fischeri (shown in black)''}} {{:Team:Cambridge/Templates/RightImage|image=photopicscotopic.png|caption=''Figure 3: Photopic (black) and scotopic (green) luminosity functions.''}} {{:Team:Cambridge/Templates/RightImage|image=photopicscotopic.png|caption=''Figure 3: Photopic (black) and scotopic (green) luminosity functions.''}} + {{:Team:Cambridge/Templates/RightImage|image=Luminosityfunction.png|caption=''Figure 4: The formula for calculating luminance. (F:Luminous Flux, y:Luminosity Function,J:Spectral Power Distribution,λ:Wavelength''}} + + + To show that it may one day indeed be possible to have bioluminescent trees replacing street lamps we considered how efficicient the plants would have to be in order to match a low-intensity street lamp. + Figure 1 shows the radiation spectrum recieved from the sun at sea level. In total this gives about 1,321 – 1,413 W/m2 of radiant energy for regions in North America. (Data supplied by[http://www.wmo.int/pages/prog/www/IMOP/publications/CIMO-Guide/CIMO%20Guide%207th%20Edition,%202008/Part%20I/Chapter%208.pdf. American Society for Testing and Materials (ASTM) Terrestrial Reference Spectra], a common standard used in photovoltaics). This is a lot of energy, but of course most of it is not accessible to plants. They can only absorb in the visible region (corresponding to roughy 45% of total solar energy), radiation known as PAR (photosynthetically active radiation). In addition, there are other constraints, such as reflectivity of leaves and the absorption spectrum of chlorophyll. The net result is that in general plants are only able to take between 3 and 6% of total solar radiation, corresponding to roughly 60 W/m2 (Figures from Hall, D.O. and House, J.I., Biomass and Bioenergy, 6,11-30 (1994).) - :$F=683.002\ \mathrm{lm/W}\cdot \int^\infin_0 \overline{y}(\lambda) J(\lambda) d\lambda$ - where - :$F\,$ is the luminous flux in [[lumen (unit)|lumen]]s, - :$J(\lambda)\,$ is the [[spectral power distribution]] of the radiation (power per unit wavelength), in watts per metre. - :$\overline{y}(\lambda)$ (also known as $V(\lambda)\,$) is the standard luminosity function (which is dimensionless). - :$\lambda\,$ is wavelength in metres.