MIT engineers unveil emissions-free cement
Electrochemical methods such as this could someday dramatically reduce greenhouse gas emissions around the planet.
- Cement production accounts for 8 percent of total carbon dioxide emissions worldwide.
- The new method uses renewable electricity to generate heat for the mixing process, while an electrochemical technique allows for carbon dioxide to be captured and stored.
- This method isn't likely to be implemented at scale anytime soon, but it's an "important first step," the researchers said.
MIT engineers have developed a new method of making concrete without emitting carbon dioxide into the atmosphere.
Cement production is the largest source of greenhouse gas emissions in industry, accounting for 8 percent of total emissions worldwide. That's why some have called on architects and builders to abandon cement.
"If we invented concrete today, nobody would think it was a good idea," said architectural engineer Michael Ramage at the Architecture of Emergency climate summit in London in September. "We've got this liquid and you need special trucks, and it takes two weeks to get hard. And it doesn't even work if you don't put steel in it."
But it seems unlikely that cement will disappear from industry, given its cheap price and reliability as a building material. So, instead of creating a new material, a group of MIT engineers decided to work toward more sustainable cement.
The new method uses an electrochemical approach that both eliminates the burning of fossil fuels and captures inevitable emissions before they seep into the atmosphere.
Preventing and capturing emissions
In a paper published in the journal PNAS on September 16, the researchers explain how CO2 is emitted at two main steps during the cement production process. The first occurs when coal is burned to cook limestone with sand and clay, the ingredients of the widely used Portland cement variety. In the new method, these materials would be heated using electricity generated from renewable sources.
"In many geographies renewable electricity is the lowest-cost electricity we have today, and its cost is still dropping," Yet-Ming Chiang, lead researcher and the Kyocera Professor of Materials Science and Engineering at MIT, told MIT News.
Emissions also occur during the chemical reactions of these materials. That's why the new approach depends on an electrolyzer, a device which uses electrodes to split water into hydrogen and oxygen. At one electrode, pulverized limestone is dissolved in acid, releasing a stream of highly pure carbon dioxide, which can be captured, stored, and potentially used for other manufacturing purposes.
Scheme for a low-emission, electrochemically based cement plant. An electrochemical decarbonation reactor powered by renewable electricity converts CaCO3 to Ca(OH)2 for use in cement synthesis
Chiang et al.
An 'important first step'
Still, there's no guarantee that the method can be scaled in a cost-effective manner. For Chiang and his team, the main goal was to spur people in the electrochemical sector to "start thinking" about ways to clean up the cement production process — to come up some innovative solutions.
"It's an important first step, but not yet a fully developed solution," Chiang told MIT News.
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Whether or not women think beards are sexy has to do with "moral disgust"
- A new study found that women perceive men with facial hair to be more attractive as well as physically and socially dominant.
- Women tend to associate more masculine faces with physical strength, social assertiveness, and formidability.
- Women who display higher levels of "moral disgust," or feelings of repugnance toward taboo behaviors, are more likely to prefer hairy faces.
Beards and perceptions of masculinity<img type="lazy-image" data-runner-src="https://assets.rebelmouse.io/eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJpbWFnZSI6Imh0dHBzOi8vYXNzZXRzLnJibC5tcy8yMjU5OTg0MC9vcmlnaW4uanBnIiwiZXhwaXJlc19hdCI6MTY0NzkxMjM3N30.cH-GqNwP5GVqvstgJWAhBPn1B_lYpVEAI0I7iax7EQw/img.jpg?width=1245&coordinates=0%2C1900%2C0%2C849&height=700" id="caae6" class="rm-shortcode" data-rm-shortcode-id="cb0a355a4e8e1899789bc45f3f7aef56" data-rm-shortcode-name="rebelmouse-image" />
Photo Credit: Wikimedia<p>The study used 919 American (mostly white) women ages 18-70 who rated 30 pictures of men they were shown with various stages of facial hair growth. The photographs depicted men with faces that had been digitally altered to look more feminine or more masculine, with a beard and without a beard. The women rated the men according to perceived attractiveness for long-term and short-term relationships. The study found that the more facial hair the men had, the higher the men were rated on their attractiveness, particularly for their suitability for a long-term relationship.</p><p>Part of this might be attributed to facial masculinity — i.e. protruding brow ridge, wide cheekbones, thick jawline, and deeply set narrow eyes — which conveys information to a woman about a man's underlying health and formidability. Women tend to associate more masculine faces with physical strength and social assertiveness. It can also indicate a man with a superior immune response. The researchers suggested that their findings favoring bearded men could be due to the fact that facial hair enhances the masculine facial features on a man's face, like creating the illusion of a thicker jaw line. This could communicate direct benefits to women like resources and protection that would enhance survival among mothers and their infants. In other words, while a beard doesn't mean superior genetics in and of itself, it might be a primitive, ornamental way of saying, "Hey girl, I'm a testosterone-fueled lean, mean, pathogen fighting machine." <br></p><p>It could also be that a beard becomes its own destiny. The researchers in this study cite prior research that found that by growing a beard, men felt more masculine and had higher levels of serum testosterone, which was linked to a higher level of social dominance. They also tended to subscribe to more old-school beliefs about gender roles in their relationships with women as compared to men with clean-shaven faces.<span></span><br></p>
What does disgust have to do with beard preference?<p>Obviously, not all women dig beards. The researchers were particularly interested in what traits make a women prefer bearded men over clean-shaven faces. They looked into several factors including a woman's disgust levels on various concepts, her desire to become pregnant, and her exposure to facial hair in her personal life. </p><p>According to the study, women who were not into facial hair were turned-off by potential parasites or other critters they imagined could be in the hair or skin. Women ranking high on this "ectoparasite disgust" scale might have viewed beards as a sign of poor grooming habits. However, women who ranked higher in levels of "pathogen" did find the bearded men to be desirable, possibly because they perceived beards as a signal of good health and immune function. An intriguing discovery in the study was links to morality. Women who displayed higher levels of "moral disgust," or feelings of repugnance toward taboo behaviors, were more likely to prefer hairy faces. The authors opined that this could reflect a link between beardedness, politically conservative outlooks, and traditional views regarding performances of masculinity in heterosexual relationships.</p>
Additional findings<img type="lazy-image" data-runner-src="https://assets.rebelmouse.io/eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJpbWFnZSI6Imh0dHBzOi8vYXNzZXRzLnJibC5tcy8yMjU5OTg1My9vcmlnaW4uZ2lmIiwiZXhwaXJlc19hdCI6MTYyNDI1NjUyOX0.P9B8WbmJR0q4nfzYZKbuNSA-2SAigVWJgrQE-_Gxlds/img.gif?width=980" id="49143" class="rm-shortcode" data-rm-shortcode-id="2ed3b1d6f20fc170bf2974646e565e8d" data-rm-shortcode-name="rebelmouse-image" />Giphy<p>The correlations that existed between married and single women's rating on the attractiveness of beards were not particularly clear, although the researchers noted that single and married women who wanted children tended to find beards more attractive than the women who didn't want children. They also found that women with bearded husbands found beards to be more attractive, which might indicate that social exposure to beards influences how desirable they are perceived of as being. Or it could be that men with wives who like beards grow beards.</p><p>It's important to note that culture plays a huge role in how attractive women perceive certain male characteristics as being. This study looked at a small, culturally specific group of American women, so no big, universal claims should be made about masculinity, facial hair, and male desirability to women. However, research like this is important in highlighting how human grooming decisions are driven by much more than fashion trends. Sociobiological, economic, and ecological factors all play a part in the way we choose to present ourselves.</p>
Dominique Crenn, the only female chef in America with three Michelin stars, joins Big Think Live.
Having been exposed to mavericks in the French culinary world at a young age, three-star Michelin chef Dominique Crenn made it her mission to cook in a way that is not only delicious and elegant, but also expressive, memorable, and true to her experience.
New experiments find weird quantum activity in supercold gas.
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Researchers say that moral self-licensing occurs "because good deeds make people feel secure in their moral self-regard."
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