• Skip to primary navigation
  • Skip to main content
  • Skip to primary sidebar

Earth Wise

A look at our changing environment.

  • Home
  • About Earth Wise
  • Where to Listen
  • Articles
  • Show Search
Hide Search
You are here: Home / Archives for microparticles

microparticles

A See-Through Heat Shield

January 8, 2019 By EarthWise Leave a Comment

It is estimated that air conditioners use about 6% of all the electricity produced in the United States for an annual cost of $29 billion.  With rising temperatures, this expense is only going to get larger.

A significant part of the heat load in buildings arises from heat coming through windows.  It turns out that for every square meter of window, about 500 watts of heat energy can be brought in by sunlight, equivalent to 5 old-fashioned light bulbs.

Researchers at MIT and the University of Hong Kong have developed a heat-rejecting film that can applied to a building’s windows that will reflect 70% of the sun’s incoming heat.  The film is similar to transparent plastic wrap. It remains highly transparent at temperatures below 89 degrees Fahrenheit.  Above that temperature, tiny microparticles embedded in the film shrink and the film becomes more translucent or frosted, still letting in a good amount of light, but rejecting a lot of heat.

There are already so-called smart windows on the market, similar to the electrochromic mirrors in cars that darken to prevent trailing headlights from blinding drivers.  But that technology is not very effective in rejecting heat and it requires power to operate, which means you would have to pay to turn windows opaque.

Tests of the new film demonstrated its ability to reject heat and lower temperatures.  The researchers estimate that if every exterior-facing window in a building were covered in the heat-rejecting film, the building’s air conditioning and energy costs could drop by 10%.  Saving ten percent of tens of billions of dollars is no minor matter.

**********

Web Links

See-through film rejects 70 percent of incoming solar heat

Photo courtesy of MIT researchers/MIT. 

Earth Wise is a production of WAMC Northeast Public Radio.

Australian Plastic Bag Ban

December 31, 2018 By EarthWise Leave a Comment

Last summer, the two largest supermarket chains in Australia – Coles and Woolworth’s – decided to stop offering single-use disposable plastic bags to customers.  The initial public reaction was decidedly negative.   However, within just three months after the radical change, the country’s National Retail Association reported an 80% drop in the consumption of plastic bags nationwide.

In that three-month period, it is estimated that 1.5 billion bags have been prevented from use.   Some retailers are reporting reduction rates as high as 90% in the use of the bags.  The move by the big supermarkets has paved the way for smaller businesses to follow suit. The smaller businesses typically can’t afford to risk the wrath of their customers with a major change like this. Customers have to learn to bring their own bags or buy reusable bags at the store.

In much of Australia, the phase-out of plastic bags has been legislated, but the state of New South Wales, home to Sydney, the country’s largest city, has not enacted such legislation. So, supermarkets themselves are doing the work of getting rid of the bags.

The change has not been without hiccups.  For the first couple of months after the plastic bag ban was put in place, Woolworth’s saw poor sales in its stores.  However, customers eventually got used to the new way of doing things and sales levels returned.

Disposable plastic bags often find their way into the oceans where they break down into microparticles. Studies have shown that these plastic bits are ingested by a wide variety of marine life.  For example, a UK study found that 100% of sea turtles in the Pacific and Atlantic oceans as well as the Mediterranean Sea had plastic in their digestive systems.

**********

Web Links

Australia-wide ban leads to ’80 per cent drop’ in plastic bag consumption

Photo, posted September 18, 2018, courtesy of Matthew Paul Argall via Flickr.  

Earth Wise is a production of WAMC Northeast Public Radio.

Primary Sidebar

Categories

  • Agriculture
  • Air and Water
  • Climate Change
  • Economy and Policy
  • Energy
  • Health
  • Invasive Species
  • Our Environment
  • Sustainable Living
  • Technology
  • Wildlife and Habitat

Archives

WAMC Northeast Public Radio

WAMC/Northeast Public Radio is a regional public radio network serving parts of seven northeastern states (more...)

Copyright © 2021 ·

  • Home
  • About Earth Wise
  • Where to Listen
  • Articles