Developments to Watch
Using Chicken Feed in the War on Superbugs
Antibiotic-resistant bacteria are becoming a huge threat. Although scientists have long speculated that antibiotics in animal feed foster the evolution of these superbugs, farmers have been loath to stop using drugs. Not only do antibiotics protect animals from disease, they also seem to promote growth, so farmers can deliver animals to market quicker.
Now, there's a new option from Mark E. Cook, an animal scientist at the University of Wisconsin at Madison. He has found an antibody that strengthens the immune system, thereby reducing the need for drugs--without slowing growth. Cook's research with chickens shows that antibiotics actually don't spur growth. They just preclude a side effect of the bird's immune system: Invading bugs trigger white blood cells to release chemicals, called cytokines, that suppress the appetite.
To block this process without impeding the immune system's ability to battle disease, Cook has created a special molecule that mops up the cytokines. When his compound is added to chicken feed, birds grow just as fast as those getting antibiotic-laced feed.By Nicole St. Pierre; Edited by Otis PortReturn to top
Yesterday's Tires, Today's Railroad Ties
Stretching across the plains and tunneling through mountains, railroads helped unite the U.S. in the 1800s--and have played a key role in transportation ever since. But those twin ribbons of steel couldn't carry freight and passengers without cross ties. And those hunks of oak are a major cost. Each year, U.S. railroads buy close to 20 million ties, at upwards of $35 each, to replace rotting ones.
On Jan. 28, Primix Corp. started production of a high-tech tie that promises to slash the cost of railway maintenance--and strike a major blow for the environment. The Atwood (Ind.) company's tie has a steel-beam core filled with concrete, and this 240-pound structure is then encased in 80 pounds of ground-up scrap tires and discarded plastic bottles, held together with a special binder, or glue.
Independent testing shows that the new tie is at least 230% stronger than creosote-soaked wood ones, says chief engineer Carl J. Fischer, "so the railroads can use fewer ties per mile." Moreover, they could last 60 to 90 years, vs. 5 to 30 years for wood. That makes the $67 price tag look like a bargain. And mountains of scrap tires could get a new life while more trees stand tall a while longer.Edited by Otis PortReturn to top
Plug-in Power for Electric Vehicles
The big hangup with electric vehicles, apart from the sheer size and cost of the batteries, is recharge time. Few drivers are willing to be stranded at a service station for several hours while the battery recharges. But what if recharging were just as fast as refueling?
By yearend, Metallic Power Inc. expects to ship prototypes of just such a system--but not to Detroit. Chairman Jeffrey A. Colborn is too savvy to bet his Carlsbad (Calif.) company on that long-term shot. Instead, he'll first go after forklift trucks, golf carts, lawn mowers, and electric wheelchairs. Then will come backup and portable power supplies for trucks, recreational vehicles, homes, small businesses, and construction sites.
What Metallic Power has developed is a unique fuel cell. In a bit more than a cubic foot, it packs enough punch to deliver 2 kilowatts--that's about what all the appliances in a typical home consume--for two hours. The projected price? Between $1,500 and $2,500, or roughly $1,000 per kw. For such heavy-duty applications as forklifts, the units can be ganged together.
What sets the system apart from other fuel cells is that its source of energy is a rechargeable "battery." It runs on cartridges filled with little zinc pellets suspended in potassium hydroxide. Plug in a cartridge, and the zinc reacts with air to produce zinc oxide, generating electricity in the process. When all the zinc has been converted, just slide in a new cartridge--and stick the old one into the company's FuelMaker box, which uses regular electricity to turn the zinc oxide back into pure zinc.
There's still no free lunch, though. Rejuvenating the cartridges takes 50% more power than they can deliver in the fuel cell.Edited by Otis PortReturn to top