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More With Manny - Science Kit

More With Manny (Frishberg)
  • Make A Wind Powered 'Thermometer'
  • How Much Oxygen Is In the Air?
  • A Question of Science: Green Mammals?
  • What Do You Mean, 'Nano?'
  • Adult Stem Cells Get to the Heart of the Matter
  • Back to Manny Frishberg Page One
  • Back to Science Online Table of Contents

    Make A Wind Powered "Thermometer"


    Using the power of the wind is one of the tricks people learned centuries ago. Windmills famously decorate the grassy Dutch hillsides, their narrow, X-shaped sails spinning giant grinding stones. On 19th century ranches and farms throughout the American west, wind turbines were used to pump precious water to the surface from deep wells. These turbines are just wheels with 15 or 20 fan blades sticking out from the center, usually made from wood or metal.

    The turbine is very good at catching the wind yet the basic design is so simple that anyone can make a working wind turbine out of stiff paper or cardboard, with only a compass, a pair of scissors and a straight-edge or ruler. Trace two circles on the paper, one 2-1/2 inches across, the second 3/4-inch, 1-3/4 inches in from the first. Draw eight lines through the center of the circles, so there are 16 sections.

    Cut along the outer circle, then cut in along the straight lines, stopping at the inner circle. To turn this into a wind turbine, bend each of the 16 fronds slightly, all in the same direction. If need be, cut a small notch on one side at the base of the blades. Put a needle into the top of a cork and place the paper wind turbine on the point, or use a pin to mount it to a straw or dowel.With such a light wind-catcher, it's unlikely for it to do any hard work, but it can measure heat like a primitive thermometer. Here's how: as air gets warm it rises in a column, making a small wind that you can catch with the turbine. Try holding it just above a heater vent when the furnace is on.

    Now, make a bright mark on one of the blades, one one that can be seen easily as it goes around. Now using a clock with a second-hand (or just counting very evenly) see how often the marked blade comes around. Next catch the heat rising from a light bulb in a table lamp. Hold the turbine a two or three distances from the bulb and count the rotations. Can you tell the difference? If you have a room thermometer, you can even make a chart showing how many RPMs (revolutions per minute) is equal to what temperature.

    Related Products: Explore concepts presented in the above article with these Science Kit Products.

    Explore Wind Power with These Kits
    Thermometers
    X-Acto Knives
    Wind Powered Generator


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    How Much Oxygen Is In the Air?


    Everyone knows that all the living things on Earth need air to breathe. Animals get the oxygen (a gas that makes up a part of the planet's atmosphere) directly, while plants take in carbon dioxide (another gas in the air, made up of oxygen and carbon atoms bound together) and use both the carbon and the oxygen in different ways. Even fish that can only live underwater breathe oxygen from the air that has dissolved in the water.

    Still oxygen is only a small part of the air we take in when we breathe. Most of the rest is an inert gas called nitrogen inert means that the nitrogen does not react easily with other chemicals it contacts. If the air was mostly oxygen or even made up a few percent more of the air, things would be bursting into flames everywhere you looked. That is because fire is what happens when burnable things combine with oxygen. One way to see just how much oxygen is in the air is to separate it out and weigh it. But separating oxygen from the rest of the gasses that make up the atmosphere requires some specialized equipment.

    Another way to measure he amount of oxygen is by volume how much space it takes up and that can be done with a few household supplies a glass bottle, preferably a tall one with a small- to medium-size mouth, a stubby candle and a deep dish partially filled with water. Make sure that the bottle will fit over the candle with a little room around the edges and that it balances upside-down in the dish.

    Place the candle in the dish of water and light it, then put the bottle over the candle flame. Since fire requires oxygen to continue burning, the flame will use up the available oxygen and snuff itself out in a few seconds. At the same time, the amount of oxygen floating free in the bottle will be reduced. Less gas in the air inside the bottle means less pressure inside as well, until the water rushes in to equalize the pressure again. By measuring the amount of water drawn into the bottle, you can get a rough idea of how much free oxygen has been consumed. It is not exact because some of the space left behind has been taken up by the smoke and carbon dioxide.

    Related Products: Explore concepts presented in the above article with these Science Kit Products.

    Hydrogen/Oxygen Generator
    Breathing Fitness Kit
    Combustion of Magnesium in Air
    Glass Bottles


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    A Question of Science: Green Mammals?



    Dear Science Question Guy

    Lots of animals have figured out the value of not-being-seen. Polar bears are white and my tabby cat can disappear in a wheat field. Birds come in all colors of the rainbow. Are there any green mammals it would be a great adaptation to all the green in the jungle?

    - Alex Severson, Beaverton, Oregon

     Alex, While most kinds of creatures on the Earth come in a variety of decorative colors including green, mammals are the exception, being, on the whole, a rather dull class of animals. The only truly green mammals I could find are from the planet Vulcan, like Mr. Spock on the classic TV series Star Trek. Don't try to adjust the color on your TV set, Vulcans have green-tinted skin because their blood uses copper instead of iron to transport oxygen. There is a problem, however. According to Brad DeLong's weblog, horseshoe crabs, a distinctly Earthen animal actually does have copper-based blood; when it fills up on oxygen it is not green but bright blue.

    In this part of the galaxy the only a few types of whales and dolphins have green-skin. Since most all mammals are covered with thick coats of fur, having green skin would do little to help camouflage them, even in dense jungles, according to Alexey Veraksa, a scientist working in the Massachusetts General Hospital Cancer Center in Boston, who answered a question very much like yours on the Ask A Scientist web site. Also, he said, since mammals tend to move around a lot, dappling or spotting, so they blend in with the patches of light and dark coming through the branches, makes for a better disguise.

    Margaretta Wallen, a professor of zoology at Sweden's Goteborg University explains that mammals can make only two kinds of pigment: melanin (black or brown pigment) and the reddish-yellow pigment that red-haired people have. Cold-blooded animals have "chromataphores" which come in several colors, including black, white, red, blue and yellow. Very few animals have green chromatophores, but can turn green by combining layers of, for example blue and yellow ones. Bird feathers can appear green as a result of microscopic features that refract (bend) the light so the green is all that is reflected.

    "The surface of feathers has microscopic ridges that form ordered tracks, much like the surface of a CD," said Veraska. The best known exception to the rule is the sloth, a tree-dwelling animal living in the "sky forest" of Central and South American jungles. The sloths not only spend their entire lives in the treetops, but hardly moves, sleeping upside-down hanging onto tree branches for 15-18 hours a day. Sloths' fur turns green when a kind of algae (single-celled plants) grow on the hairs during the rainy season. The algae not only provides protective coloring but a sort of vitamin supplement for the sloths when they lick their fur.

    Related Products: Explore concepts presented in the above article with these Science Kit Products.

    Feathers, Fur and Scales
    Spectrum Analysis Chart
    Wild Survivors: Camouflage & Mimicry Video
    Mammals, Cages, Study Kits and Teaching Aids
    The Physics of Color


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    What Do You Mean, "Nano"?



    One of this year's hot topics in science has been nanotechnology, that is, making objects and machines with parts on the order of one thousand times smaller than a human hair. If that seems a little vague, it is because there is no generally agree upon definition of exactly what the "nano" in nanotechnology means.

    Nanotechnology is concerned with atomic- and molecular-scale devices. Researches have been making jumbles of molecule scale tubes, balls (called "fullerenes" or "Bucky-balls") and and tubes made up of just 10 to 1,000 atoms.

    Agreeing on terms to describe what they are doing has become essential, so in September more than 100 experts from universities, industry, government, law and other subjects came to the first meeting of the Nanotechnology Standards Panel of the American National Standards Institute to start the process of coming up with a set of standards everyone can agree on. They hope to have a definition of the different shapes and forms being produced, as well as what precisely what "nano" is. They also want to look at how to measure risks to the environmental health and safety and possible toxic effects. Developing standard testing methods and ways of reading the results are also being talked about.

    As scientists get better at fashioning particular designs and shapes for nanotubes and learn to make them longer or arrange them in a certain order, talk about what might be possible with them, such as making nano-thin wires and transistors that operate on just a few electrons has spurred a lot of excitement. So far, though, most of what has made it out of the lab and into the stores are coatings, like one to make stain-resistant fabrics. But scientists foresee applications in everything from computers to medicine, and beyond.

    The standard-setting group wants the results of their work to be voluntary. To get their recommendations accepted by scientists and the industry they are working on having as many interested groups as possible join in the process. Nano-devices can be built using a scanning tunneling electron microscope, which can move single atoms around or deposited on a mold one layer of molecules at a time. Nonocables are being made t hat way by chemical engineers at the University of California in Davis, led by Prof.Pieter Stroeve. The way the nanocables conduct electricity changes when they are exposed to different chemicals or toxins, so they could be used for tiny sensors. They could also be used to make more powerful computer chips.

    A third approach is to grow such devices from proteins or organic molecules produced in the lab. Chemist George M. Whitesides has used self-assembling hydrocarbon molecules that "grow" themselves into functioning items like living cells do.

    Related Products: Explore concepts presented in the above article with these Science Kit Products.

    Buckminsterfullerenes (Buckyballs) Kit


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    Adult Stem Cells Get to the Heart of the Matter



    Cells taken from a person's own heart may be used to repair the damage caused by a heart attack, if an experiment done on pigs proves to work as well with humans. Medical researchers at Johns Hopkins Medical Center in Baltimore took heart stem cells for a pig and grew them in a lab dish and injected them back into the pig to grow new healthy heart tissue.

    The kind of stem cells being used in this trial are different from the "embryonic stem cells" that have been in the news in recent months. These cells are found in small numbers in a person's (or a pig's) heart and are already pre-programmed to become heart muscle. Working with seven pigs that had damaged hearts, similar to what happens when a person has a heart attack, the new stem cells renewed their hearts to normal condition in about two months. The study was carried out by two professors of medicine Dr. Joshua Hare and Dr. Alan Heldman, an interventional cardiologist, and their team. The results were made public at a scientific meeting sponsored by the American Heart Association.

    Heart attacks occur when blood flow to the heart is blocked, starving the muscle of oxygen. Doctors have become fairly good at preventing or treating heart attacks when they happen. Heldman said damage to heart muscle can disrupt heart rhythms, which can lead to sudden cardiac death. A weakened heart cannot pump as hard as it should, leading to congestive heart failure. If it continues to work in other animals and humans, this approach would give doctors a way to repair the actual damage for the first time.

    "Current treatments," Dr. Hare said in a press statement, "do not repair the damaged muscle that results, leaving sizably dead portions of heart tissue that lead to dangerous scars in the heart." Heldman said their goal is to "repair the damage done to the heart muscle and prevent these complications."

    In another experiment from t he Baltimore institution, scientists at the Johns Hopkins University School of Medicine tried something very similar with 23 patients with heart failure, taking small samples of tissue that contained heart stem cells by threading a probe through a vein. The cells were grown into clusters called "cardiospheres" (literally "heart-balls"), like the ones reintroduced into the pigs in the other experinment.

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    GPI Anatomicals Heart Model
    Heart Manipulative Model
    Biotechnology and Genetics
    Irradiated Seed Germination Lab Activity


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