By Raida Kifait Reza
It was a like a fantasy land these last months, without power failures haunting us. And the load shedding starts fuelling up, the search for power continues. The primary sources of power are found to be the new stench of corruption, digital power, financial troubles, fights…but let's not get into that. This week, we find out how other sources of power can salvage us…or just the idea of salvaging us…
In the study, Di Zhang and colleagues note that scientists are searching for new materials to improve light harvesting in so-called dye-sensitized solar cells, also known as Grätzel cells (lets call it X) after the inventor Michael Grätzel. These cells have the highest light-conversion efficiencies among all solar cells as high as 10 percent!
The researchers turned to the microscopic solar scales on butterfly wings in their search for improvements. Using natural butterfly wings as a mold or template, they made copies of the solar collectors and transferred those light-harvesting structures to X. Laboratory tests showed that the butterfly wing solar collector absorbed light more efficiently than conventional dye-sensitized cells. The fabrication process is simpler and faster than other methods, and could be used to manufacture other commercially valuable devices, the researchers say.
It turns out they both can, it just depends on the nature of the task or message. Interestingly, the brain has a strange power of receiving different colours! The study, which could have major implications for advertising and interior design, finds that red is the most effective at enhancing our attention to detail, while blue is best at boosting our ability to think creatively. Hint hint! Wear red to catch his or her eye!
"Previous research linked blue and red to enhanced cognitive performance, but disagreed on which provides the greatest boost," says Juliet Zhu of UBC's Sauder School of Business, author of the study which appeared in the Feb. 5 issue of Science.
Between 2007 and 2008, the researchers tracked more than 600 participants' performance on six cognitive tasks; most experiments were conducted on computers, with a screen that was red, blue or white. Red boosted performance on detail-oriented tasks such as memory retrieval and proofreading by as much as 31 per cent compared to blue. Conversely, for creative tasks such as brainstorming, blue environmental cues prompted participants to produce twice as many creative outputs as when under the red colour condition.
Conversely, blue encourages us to think outside the box and be creative, says Zhu, noting that the majority of participants believed incorrectly that blue would enhance their performance on all cognitive tasks.
"Through associations with the sky, the ocean and water, most people associate blue with openness, peace and tranquility," says Zhu, who conducted the research with UBC PhD candidate Ravi Mehta.
Experts estimate that each year people dump more than 200 million gallons of used oil into sewers, streams, and backyards, resulting in polluted wastewater that is difficult to treat. Although there are many different sorbent materials for removing used oil, such as activated carbon, they are often costly and inefficient. Hydrophobic silica aerogels are highly porous and absorbent material, and seemed like an excellent oil sponge.
The scientists packed a batch of tiny aerogel beads into a vertical column and exposed them to flowing water containing soybean oil to simulate the filtration process at a wastewater treatment plant. They showed that the aerogel beads absorbed up to 7 times their weight and removed oil from the wastewater at high efficiency, better than many conventional sorbent materials!
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