Member 591
5 entries

Contributor to project:
What happened to nature?
Denis Lirette (M)
Toronto, CA
Immortal since Dec 12, 2007
Uplinks: 0, Generation 2

About Me
  • Affiliated
  •  /  
  • Invited
  •  /  
  • Descended
  • denis’ favorites
    From N8
    They Can "See" Your Dreams?
    From Andy Gilmore
    From aaron kinney
    New X Prize Aims For The...
    Recently commented on
    From denis
    New kind of adhesive from...
    denis’ project
    What happened to nature?
    How to stay in touch with our biological origins in a world devoid of nature? The majestic nature that once inspired poets, painters and...
    Now playing SpaceCollective
    Where forward thinking terrestrials share ideas and information about the state of the species, their planet and the universe, living the lives of science fiction. Introduction
    Featuring Powers of Ten by Charles and Ray Eames, based on an idea by Kees Boeke.

    After years of saying habitable exoplanets are just around the corner, planet hunters have finally found one. Gliese 581g is the first planet found to lie squarely in its star’s habitable zone, where the conditions are right for liquid water.

    Read More: 
    Thu, Sep 30, 2010  Permanent link
    Categories: Earth, Planet
      RSS for this post
      Promote (1)
      Add to favorites
    Create synapse
    A radical new method of producing electricity from the Earth's inner heat has been devised by a power plant designer from Texas.

    Doyle Brewington of ESOR Consulting Engineers in Houston has designed a long, self-contained turbine shaft called a Power Tube that could tap subterranean heat without relying on geysers and steam vents.

    "I spent 25 years building power plants and I saw the damage they were causing," Brewington said. "The noxious gas being emitted by a lot of these steam turbines were causing a lot of acid rain around the world."

    Brewington's Power Tube is a sealed tube, four-foot wide and 185-feet long, containing a vapor-driven generator. The idea is to bury the Power Tube deep enough to touch hot rock.
    The tip of the Power Tube contains a pair of hydrocarbons, isopentane and isobutene, that turn to vapor when in contact with rock that's at least 220 degrees Fahrenheit (104 C). The vapor rises to drive a generator above. The vapor is then cooled back into a liquid by helium that is compressed and expanded using sound waves. The liquefied hydrocarbons are then pumped back to the tip to restart the cycle in an unbroken loop. Magnetic suspension, rather than lubrication, eliminates friction in the turbine.

    Brewington has designed a half-size prototype that is just over two-feet in diameter and 85 feet long. It is expected to produce a megawatt of electricity, enough to power 750 homes. The first Power Tubes to go into operation will be in Hawaii and Costa Rica, Brewington said. He is still talking to authorities, and didn't say when it would go into the ground.

    Brewington said full-size Power Tubes will produce 10 MW, enough to light up a small residential town. Unlike old-fashioned geothermal sites, which consume up to 10 acres of land, Power Tubes will have only a small maintenance shed on top. And because Power Tubes run silently, homes and offices could be built over them.

    Working Power Tubes will be easy to assemble on site: Long ones will be transported in sections, Brewington said. And on-site maintenance of a Power Tube would be swifter than that for traditional power plants because the entire shaft can be removed and replaced in hours. The defective tube could then be retrofitted back at the plant.

    If Brewington is correct, much of the energy needed for expanding industrialization could be provided without releasing greenhouse gases associated with burning fossil fuel or the risks associated with nuclear energy.

    Many of the fastest growing economies sit on the Earth's "Ring of Fire," a circuit of volcanoes, earthquakes, and other manifestations of tectonic tension. Brewington claims that 48 countries in the Ring of Fire alone could be powered entirely by Power Tubes, a great stride over other geothermal systems.

    "Anything that's got magma underneath it is great," he said.

    But leading researchers are watching with a wary eye, and some have expressed strong reservations about Brewington's plans. They don't see how he's going to pull off his power plans without water.

    In geothermal plants, water plays the vital role of a heat conductor. Designs for extracting electricity from hot, dry rocks have hit a very basic and frustrating wall — the rocks cool down too fast, noted John Lund, director of the Geo-Heat Center at the Oregon Institute of Technology.
    "The process is feasible in the short term. There's no question about that," said Lund. But "rock is very poor at transferring heat. You're pulling heat out to turn the turbine, so the surrounding rock cools down and new heat is very, very slow to replenish.

    "If not (in) a month, maybe after a year, and he'll be out of heat. I don't think the process he has in mind is going to work very well."

    Lund said there are already geothermal power plants using a process called binary cycles that use hydrocarbon vapors in much the same way as Brewington's Power Tubes. The critical difference is that when these plants are situated in a dry area, they pump water down at high pressure to exploit fissures in the rock so that water can then conduct heat from a wider area.
    A plant built for sustained operations needs to draw upon a heat well hundreds, if not thousands, of feet deep, Lund said. Considering the geology of the United States, Lund said nothing east of the Mississippi could meet a Power Tube's needs at the shallow depths proposed by Brewington. "So the economics defeats him and the heat transfer of rock defeats him," Lund concluded.

    Ted Clutter, executive director of the Geothermal Resources Council, an industry advocacy group, would only say that Power Tubes are "not something we're interested in."

    A Department of Energy spokesman said the agency's experts weren't familiar enough with Brewington's plans to offer an evaluation.

    Read More 
    Wed, Oct 27, 2010  Permanent link
    Categories: Earth, Planet, Core, Electricity
      RSS for this post
      Promote (3)
      Add to favorites
    Create synapse

    After a 22-hour ride through the 3.7-billion-year-old, lava-gorged Taurus-Littrow Valley, astronauts Eugene Cernan and Harrison "Jack" Schmitt parked their rover near the Apollo 17 Lunar module, mounted the steps, secured the door, and headed back home to Earth. They were the last humans to leave footprints on the moon.

    Now some 26 years later, we are beginning to think about a return trip to Earth's sole natural satellite. What draws us back to the pockmarked lunar surface?

    As the century wanes, interest in lunar travel comes not so much from NASA as from the private sector. The passion of the 1960s and '70s for discovery and dominance in space has given way to the possibility of extraterrestrial profit-from mining the moon's surface to building an out-of-this-world resort. These opportunities have become more realistic since Lunar Prospector's 1998 discovery of water ice on the moon. Water is not only necessary for human survival but its hydrogen and oxygen molecules also make terrific rocket fuel.

    "Primarily, the existence of water opens people's minds about going to the moon," said Alan Binder, Prospector's chief scientist, in an interview with Discover magazine. "It doesn't seem like such a foreign place. It's like finding gold. California could have been settled without the gold rush, but it sure helped."

    The shift in focus from exploration of the lunar surface to exploitation of lunar resources raises new ethical challenges for us. Who will profit from these resources, or, as some have phrased it, "Who owns the moon?"

    One way to answer these questions is through the eyes of stewardship. Stewardship envisions humans not as owners of the moon but as responsible managers of its resources. We are held accountable for a prudent use of those resources. Such responsibility may support revived lunar exploration but at the same time challenge unreflective exploitation.

    As we contemplate colonizing the moon, we should remember that we have not always done enough to protect our home environment. Our disposal of chemicals into waterways has brought us fish and water unfit for human consumption; our marriage to the car has brought us watery eyes and "Spare the Air" days. What have we learned from our treatment of the earth and the air about the protection of the moon and the stars? What will we leave besides footprints in the lunar dust?

    Strikingly, humans are the only earthly species with a capacity to have impact not only on the moon but also on the entire solar system. This gives us a special responsibility to recognize that, despite the depths of the universe, there might not be so much space out there that it can meet every demand we place on it or suffer mistreatment lightly. Allow me to propose three guidelines for thinking about this final frontier:

    1) Space preservation insists that we value space for its own sake, whether or not it benefits humanity in terms of knowledge, leisure time, or Wall Street profits.

    2) Space conservation asks that we take care of the universe's resources for the sake of others and avoid exploitation to benefit the few.

    3) Space stewardship demands that humans be held accountable for the management of planetary resources. Each person is responsible for the stewardship of his or her life and the environment in which it is lived. Such an attitude promotes the common good by requiring us to consider how our actions affect others, our vast surroundings, and the future. Individual dignity and well-being are strengthened and supported by preserving a universe in which we can thrive under and with the moon and the stars.

    Article by Margaret McLean
    Thu, Jan 17, 2008  Permanent link

      RSS for this post
      Promote (1)
      Add to favorites
    Create synapse
    Biomimicry is a relatively new science that studies models, systems and processes from nature and attempts to imitate or take creative inspiration from them to solve human problems sustainably.

    Researchers at the Max Plack Institute for Metals Research in Stuttgart, joining forces with Gottlieb Binder GmbH in Holzgerlingen, are developing new kinds of adhesive material modeled on the soles on insects' feet.

    Mushroom-shaped microhairs are the secret of a new adhesive material which scientists at the Max Planck Institure for Metals Research in Stuttgart have developed. Inspired by soles of beetles' feet, and therefor biomometic, the special surface structure of material allows it to stick to smooth walls without any adhesives. Potential applications range from reusable adhesive tape to shoe soles for climbing robots and are therefore of considerable relevance to technology.

    Journal of the Royal Society Interface, 17 October 2006
    Wed, Dec 12, 2007  Permanent link

    Sent to project: What happened to nature?
      RSS for this post
      Promote (5)
      Add to favorites
    Synapses (1)

    No one owns the North Pole, but every country with a border on the Arctic Ocean claims some of its waters. Because the North Pole is covered by an ice shelf and isn't actually land, it is governed by the Law of the Sea, a 1982 U.N. treaty signed by more than 150 countries. The agreement gives each nation control of the area up to 200 nautical miles (230 miles) off its coast, so everyone with so much as a shoreline in the Arctic gets some Arctic waters and whatever natural resources might lie beneath them.

    This seemingly straightforward rule is complicated by another regulation that allows countries to extend their waters to up to 350 nautical miles (403 miles) if they can prove their underwater continental shelf extends beyond the normal 200-mile boundary. In other words, we don't fully know who owns the Arctic until we know the shape of the underlying seabed.

    Original article by Lee Hudson Teslik

    Wed, Dec 12, 2007  Permanent link
    Categories: Arctic, Earth, Planet
      RSS for this post
      Promote (4)
      Add to favorites
    Create synapse