|Ken Novak's Weblog
Purpose of this blog: to retain annotated bookmarks for my future reference, and to offer others my filter technology and other news. Note that this blog is categorized. Use the category links to find items that match your interests.
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Monday, August 04, 2003
Solar Cell Pushes Efficiency Barrier
: "Spectrolab, a subsidiary of The Boeing Company has achieved an what they claim is an unprecedented conversion efficiency for a terrestrial concentrator solar cell. Using concentrated sunlight, these photovoltaic (PV) cells can convert 36.9 percent of the sun's energy to electricity,.. "During the last few years, multijunction solar cells have doubled the power output of large commercial satellites. We believe that further optimization of the improved terrestrial concentrator cells will yield the potential to surpass 40 percent conversion efficiency," said Dr. Nasser Karam, Spectrolab vice president for Advanced Technology. " The tested cell was .25 square centimeters in size. It was an improvement over the last generation by being tuned to terrestrial, rather than space, sunlight. Press release
says that several modules are already being tested throughout the world by photovoltaic concentrator system manufacturers. The research was funded by NREL and the Air Force. 8:03:02 PM
Revolutionizing Science and Engineering Through Cyberinfrastructure
: Executive summary of NSF Blue Ribbon Advisory Panel report. "The Panel's overarching finding is that a new age has dawned in scientific and engineering research, pushed by continuing progress in computing, information, and communication technology, and pulled by the expanding complexity, scope, and scale of today's challenges. The capacity of this technology has crossed thresholds that now make possible a comprehensive “cyberinfrastructure” on which to build new types of scientific and engineering knowledge environments and organizations and to pursue research in new ways and with increased efficacy." 2:58:06 PM
Redwoods go high tech, and High-tech trees take their own temperature: Berkeley researchers use new wireless motes in forest research: "For years, Dawson's research on the moisture that giant redwoods absorb from fog has involved the installation of 30 pounds of gear - including data loggers, sensors and wires - onto trees that stand 300 feet tall in the redwood groves of Santa Cruz and Sonoma counties. Each [new] wireless sensor, or micromote, measures less than three cubic inches and is capable of transmitting radio signals at 50 kilobytes per second. .. "These devices need to run for months on a size C battery, streaming a variety of environmental data out of the trees for data processing," said Culler. ..
The old, industrial-age sensors cost $3,000, while the Mica sensors -- made by Crossbow Technologies of Santa Clara using UC Berkeley technology -- cost about $250 each. The motes accurately chart temperatures and humidity and show the profound differences between tree tops and branches near the bottom.. Other sensors to be added include one equipped with a tiny probe to measure the interior temperature of the tree and the velocity and quantity of water flowing inside the tree.. "
The redwood grove used in the test are at the UC Botanical Garden in Strawberry Canyon. The researchers plan to expand the wireless network later this year to include redwood groves in Big Basin Redwoods State Park in Santa Cruz County and at a site in Sonoma County.
Project Leader is "David Culler, a UC Berkeley professor of computer science, and his researchers, along with a team led by UC Berkeley computer scientist Kris Pister, who calls the technology "smart dust." While Pister's team worked to make the motes smaller and smaller, Culler wrote an operating system for the tiny computers onboard. He called it "tinyOS." .. Other researchers on the project include Robert Szewczyk and Joe Polastre, UC Berkeley graduate students in electrical engineering and computer sciences, and Wei Hong and David Gay, researchers at the Intel Research Berkeley laboratory. "
Companies: In addition to Crossbow Technologies, "one San Jose company, Digital Sun, is marketing a sensor system designed for gardeners that monitors temperature and soil moisture and waters the plants when they need it. A Massachusetts company, Sensicast Systems, is also marketing tinyOS sensor systems. Bosch and Honeywell are also looking into wireless sensor nets. Wineries are very interested in the possibility of precisely monitoring areas or plants within vineyards, and several are working with Intel on a project. " 2:49:21 PM
Digital (Fill in the Blank) Is on the Horizon: "Since 1999, just before the technology boom collapsed, the percentage of households in the United States with personal computers — which many experts thought was leveling off — has in fact increased to 64 percent from 50 percent. At the same time, the share of households online has risen to 59 percent from 33 percent, and the use of digital cameras has climbed to 17 percent of households from less than 3 percent, according to Odyssey's research. ..
[A new] project, called Mealtime, will run for about four months, beginning the middle of this month. The companies supplying equipment and technology include Whirlpool, Icebox, IBM, Hewlett-Packard and Sears. Besides the networked oven that can also chill food, each household will have a refrigerator linked to the Internet for automated reordering of groceries through Peapod, the online grocer." 1:29:33 PM