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Sean Nash

Common plastics could passively cool and heat buildings with the seasons | ScienceDaily - 0 views

  • Researchers at Princeton and UCLA have developed a passive mechanism to cool buildings in the summer and warm them in the winter.
  • coatings engineered from common materials can achieve energy savings and thermal comfort that goes beyond what traditional building envelopes can achieve
  • "With the increase in global temperatures, maintaining habitable buildings has become a global challenge,"
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  • "In recent years there has been massive interest in cool roof coatings that reflect sunlight. But cooling walls and windows is a much more subtle and complex challenge."
  • "By coating walls and windows with materials that only radiate or absorb heat in the atmospheric window, we can reduce broadband heat gain from the ground in the summer, and loss in the winter, while maintaining the cooling effect of the sky. We believe that this idea is unprecedented, and beyond what traditional roof and wall envelopes can achieve."
  • The findings' impact is significant for two important reasons. First, the researchers show in the article that many common and low-cost building materials radiate heat in the narrowband and block broadband heat. Material such as polyvinyl fluoride, already used as siding material, could be adapted for the purpose, as could even more common plastics.
    • Sean Nash
       
      Smells like feasibility....
  • "We were really excited when we found that materials like Polypropylene, which we sourced from household plastics, selectively radiate or absorb heat in the atmospheric window." Raman noted. "These materials border on the mundane, but the same scalability that makes them common also means that we could see them thermoregulating buildings in the near future."
  • The second reason for optimism is that the potential energy impacts at the building scale are substantial. The researchers noted that seasonal energy savings with their mechanism are comparable to the benefits of painting dark roofs white. This could be useful as air conditioning cost and heat related casualties continue to soar worldwide. Mandal and Raman plan to continue this research further.
  • "The mechanism we proposed is completely passive, which makes it a sustainable way to cool and heat buildings with the seasons and yield untapped energy savings."
  • Journal Reference: Jyotirmoy Mandal, Jyothis Anand, Sagar Mandal, John Brewer, Arvind Ramachandran, Aaswath P. Raman. Radiative cooling and thermoregulation in the earth’s glow. Cell Reports Physical Science, 2024; 102065 DOI: 10.1016/j.xcrp.2024.102065
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    Don't know if you're following changes in climate, but... this might be an area for some engineering. What are the other problems involved with this field of study? Interesting to anyone?
Sean Nash

New fabric makes urban heat islands more bearable | ScienceDaily - 0 views

  • This year has already seen massive heatwaves around the globe, with cities in Mexico, India, Pakistan and Oman hitting temperatures near or past 50 degrees Celsius (122 degrees Fahrenheit).
  • In tests under the Arizona sun, the material kept 2.3 degrees Celsius (4.1 degrees Fahrenheit) cooler than the broadband emitter fabric used for outdoor endurance sports and 8.9 degrees Celsius (16 degrees Fahrenheit) cooler than the commercialized silk commonly used for shirts, dresses and other summer clothing.
  • "You can save a lot of cooling, electricity and energy costs because this is a passive process," Sui said.
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  • Spectrally engineered textile for radiative cooling against urban heat islands. Science, 2024; 384 (6701): 1203 DOI: 10.1126/science.adl0653
    • Sean Nash
       
      I'm not yet convinced of the feasibility of this one, but this might provide a spark for someone. Some types of materials engineering like this is done on a nanoscale, which may not be the best for what we can do... but I believe there is space here for exploring composite materials with different properties to engineer better outcomes than what we're currently dealing with.
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    "With applications in clothing, construction and food storage, the new textile reduces heat from both the sun and thermal radiation from nearby buildings"
Sean Nash

New fabric cools people in sweltering cities - 0 views

  • researchers have designed a new wearable fabric to help people beat the heat in urban settings. The material, reported in the journal Science, could find use in clothing, cooling facades for buildings and cars, and for food storage and transport.
  • Existing cooling fabrics reflect sunlight and also wick away sweat to cool a person via evaporation. More recently, researchers have designed cooling fabrics that rely on the principle of radiative cooling: the natural phenomenon in which objects radiate heat through the atmosphere straight into outer space.
  • But radiative cooling fabrics made so far are designed to work when laid horizontally as opposed to vertically, as they would be when worn.
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  • researchers at the University of Chicago made a new three-layer fabric. Its wool bottom layer wicks heat from the skin to the middle layer, which is made of silver nanowires that block heat from coming in. The top layer selectively emits heat into the atmosphere.
  • In tests conducted in the urban heat island of Chicago and under blistering Arizona sun, the material stayed 2.3°C cooler than sports cooling fabrics and 8.9°C cooler than commercial silk used for summer clothing.
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    Materials science is certainly a nifty bit of engineering. This is the second time I've seen this study mentioned. Look interesting enough to dig into various materials and how they might be combined to serve a key purpose?
Kylie John

The Role of Reactive Oxygen Species in Plant Response to Radiation - PMC - 0 views

  • ROS (Reactive oxygen species) are reactive oxidants in plant cells, including hydrogen peroxide (H2O2), superoxide anions (O2•−) and hydroxide anion radicals (·OH), which may stimulate the antioxidant system of plants and act as signaling molecules to regulate downstream reactions.
Sean Nash

Uncovering the role of solar radiation and water stress factors in constraini... - 0 views

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    This is an interesting possibility for working with large (already-existing) datasets to map out and correlate data about the spring reset for plants. What factors are most important in when the spring "greenup" starts? Could also be combined with some local data collected to compare the datasets with what we are seeing on the ground. Could also be a cool opportunity to use ArcGIS tools for spatially mapping information geographically over time!
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