JUNCTION SOLUTION: TRAFFIC SIGNAL COORDINATION TO REDUCE AIR POLLUTION
Researchers from Lehigh University in Pennsylvania, USA, are working on coordinating traffic signals with an eye on reducing air pollution in cities. For instance, a traffic signal with a longer duration of red light would mean more vehicles accumulating at that junction, contributing to higher pollution levels.
It becomes a problem for everybody, especially those with asthma and other health conditions. The researchers are now developing a three-pronged method that could allow a more consistent traffic flow with fewer or shorter stops at signals to minimise polluting emissions.
They are developing a low-cost, mobile air quality sensing system to identify areas of high pollution. An area with a hospital, for example, might harbour large numbers of sensitive individuals. The researchers are using a reinforcement learning method to incorporate traffic signals around a city and simulate how traffic signal control helps improve air quality.
It is also the first project of its kind to incorporate a social component into a traffic control system. Researchers envision a traffic management system that would enable transportation officials to control signals in real time and a web-based system that will show city residents location-specific air quality levels so they can make informed decisions about activities.
The research extends to other modes of transportation like electric bikes and scooters. They are also working on making micro-mobility systems more efficient. These systems allow users to rent alternative vehicles for transportation, which would also reduce air pollution.
SOLAR MIMIC: WAY FOUND TO CONVERT INDOOR LIGHTING INTO ELECTRIC ENERGY
Scientists supported by multinational sources of funding are working on identifying photovoltaic systems that can convert indoor light into electrical energy to power smart home appliances better. The principle works in the same manner as converting sunlight into solar power, albeit much less power, but sufficient to run homes.
Indoor lighting differs from sunlight. Light bulbs are dimmer than the Sun. Sunlight comprises ultraviolet, infrared and visible light, while indoor lights shine from a narrower region of the spectrum. Although scientists have found ways to harness sunlight using PV solar panels, those panels are not optimised for converting indoor light into electrical energy.
Now, researchers have brought solar panel technology indoors to power smart devices. They show which photovoltaic (PV) systems work best under cool white light-emitting diodes (LEDs), a common type of indoor lighting these days. After comparing a range of different PV technologies under the same type of indoor lighting, they found that Gallium indium phosphide PV cells showed the greatest efficiency under indoor light, converting nearly 40% of the indoor light energy into electricity.
Gallium indium phosphide has not been used in commercially available PV cells yet, but this study points to its potential beyond solar power, according to the researchers. But there is a problem. The gallium-containing materials are expensive and may not serve as a viable mass product to power smart home systems as yet.
In contrast, perovskite mineral and organic film PV cells are less expensive and do not have stability issues under indoor lighting conditions. In all, researchers have at least put their fingers on PV systems that can convert indoor light into electrical energy. The way forward has been found, but means to popularise them need to be established.
