Tech & Science
Technology and Science news from Boulder, Colorado
‘Catching Your Future’ college fair set for Nov. 13
Nov 3rd
What: Catching Your Future college fair
When: Saturday, Nov. 13, 11:30 a.m.-4:30 p.m.
Where: Front Range Community College, 2121 Miller Drive, Longmont
The fair offers five workshops for families, all of which will be presented in English and Spanish:
• Funding Your Future, assistance with the Free Application for Federal Student Aid and scholarship opportunities
• Take Action Now, learn about concurrent enrollment opportunities
• Making Your Statement, help in writing scholarship essays
• Paving Your Way to College, educating students about civic engagement and the importance of volunteering
• College for All Students, nontraditional pathways and opportunities for college
Participants attending a minimum of three workshops will be eligible to win prizes, including Netbooks, iPods, and scholarships totaling more than $2,000.
SOURCE: BOULDER COUNTY NEWS RELEASE
Local colleges and universities will participate, including Colorado, Colorado State, Mesa State, Northern Colorado, Regis and more. Families can also visit with local agencies that support students in reaching their educational goals.
The fair is organized by Sharing Achievement For Student Success in Education, a student-led organization whose focus is to help Boulder County’s low-income, minority, and first-generation students achieve their goals for higher education.
Last year’s fair reached more than 250 county families and awarded more than $3,000 in scholarships.
ORIGIN OF SKILLFUL STONE TOOL SHARPENING METHOD PUSHED BACK MORE THAN 50,000 YEARS
Oct 29th
A highly skillful and delicate method of sharpening and retouching stone artifacts by prehistoric people appears to have been developed at least 75,000 years ago, more than 50,000 years earlier than previously thought, according to a new study led by the University of Colorado at Boulder.
The new findings show that the technique, known as pressure flaking, took place at Blombos Cave in South Africa during the Middle Stone Age by anatomically modern humans and involved the heating of silcrete — quartz grains cemented by silica — used to make tools. Pressure flaking takes place when implements previously shaped by hard stone hammer strikes followed by softer strikes with wood or bone hammers are carefully trimmed on the edges by directly pressing the point of a tool made of bone on the stone artifact.
The technique provides a better means of controlling the sharpness, thickness and overall shape of bifacial tools like spearheads and stone knives, said Paola Villa, a curator at the University of Colorado Museum of Natural History and a study co-author. Prior to the Blombos Cave discovery, the earliest evidence of pressure flaking was from the Upper Paleolithic Solutrean culture in France and Spain roughly 20,000 years ago.
“This finding is important because it shows that modern humans in South Africa had a sophisticated repertoire of tool-making techniques at a very early time,” said Villa. “This innovation is a clear example of a tendency to develop new functional ideas and techniques widely viewed as symptomatic of advanced, or modern, behavior.”
A paper on the subject was published in the Oct. 29 issue of Science. Other study co-authors included Vincent Mourre of the French National Institute for Preventive Archaeological Research in France and Christopher Henshilwood of the University of Bergen in Norway and director of the Blombos Cave excavation. The research was funded by the Wenner Gren Foundation of New York.
“Using the pressure flaking technique required strong hands and allowed toolmakers to exert a high degree of control on the final shape and thinness that cannot be achieved by percussion,” Villa said. “This control helped to produce narrower and sharper tool tips.” The bifacial points, known as Still Bay points, likely were spearheads, she said.
The authors speculated that the pressure flaking technique may have been invented in Africa and used sporadically before its later, widespread adoption in Europe, Australia and North America. North American archaeologists have shown that Paleoindians used the pressure flaking technique to fashion stone points likely used to hunt a menagerie of now-extinct mammals like mammoths, mastodons and ancient horses.
With the exception of obsidian, jasper and some high-quality flint, few stone materials can be pressure flaked without first heating them, Villa said. While there is evidence of silcrete heating some 164,000 years ago at the Pinnacle Point site in South Africa, the Blombos Cave artifacts are the first clear evidence of the skillful pressure flaking technique being used to carefully shape, refine and retouch tools, said Villa.
There are several ways to confirm whether silcrete has been heat-treated, Villa said. Archaeologists at Pinnacle Point used two common methods called thermoluminescence and archaeomagnetism that require the destruction of stone tool samples, as well as a non-destructive technique known as maximum gloss analysis.
Villa, Mourre and Henshilwood used a visual method for the Blombos Cave artifact analysis based on the contrast between heated and unheated tool surfaces observed microscopically at low magnification. While the removal of flakes from unheated silcrete produces scar surfaces with a rough, dull texture, heat-treated silcrete scar surfaces have a smooth, glossy appearance, said Villa.
The researchers analyzed 159 silcrete points and fragments, 179 other retouched pieces and more than 700 flakes from a layer in Blombos Cave linked to the so-called Still Bay industry, a Middle Stone Age tool manufacturing style that started roughly 76,000 years ago and which may have lasted until 72,000 years ago. The researchers concluded that at least half of the ancient, finished points at Blombos Cave were retouched by pressure flaking.
In addition to the microscopic analysis of the tools, the team also used experimental replication to show that pressure flaking was used in the final retouching phase of the points. The shaping of both heated and non-heated tools — known as knapping — was done by Mourre using silcrete chunks collected by Henshilwood from outcrops roughly 20 miles from Blombos Cave.
The silcrete samples used in the replication stage of the study were heated by Henshilwood in collaboration with Kyle Brown of Arizona State University, who published a 2009 paper in Science on the heat-treatment of silcrete in South Africa.
The team members compared attributes of points and flakes created for the experiments by percussion and pressure with points and flakes found in Blombos Cave, finding that unheated silcrete chunks first shaped with quartzite stone hammers and further worked on with wooden hammers known as billets could not be pressure flaked.
“Pressure flaking adds to the repertoire of technological advances during the Still Bay (period) and helps define it as a time when novel ideas were rapidly introduced,” wrote the authors in Science. “This flexible approach to technology may have conferred an advantage to the groups of Homo sapiens who migrated out of Africa about 60,000 years ago.”
SOURCE: CU MEDIA RELEASE
Boulder facility goes ‘off the grid’ generating total power from non-fossil fuels for first time
Oct 29th
In this case, Coordinator of Wastewater Treatment Chris Douville explained, the plant was able to draw all of the energy it needed, roughly 1,200 to 1,400 kilowatts at any given moment, from the solar array and from its two co-generation (co-gen) system engines. The co-gen engines capture and burn the gas that is coming off the anaerobic digester process tanks, using that gas to generate additional power instead of releasing it into the atmosphere. The solar system, when at its peak on Thursday, was generating close to 800 kilowatts.
Douville said the success was attributable to a combination of factors, including relatively low wastewater flows, less demand than usual, a clear solar day and cooler temperatures. Data captured at the plant shows the milestone was reached at 11:30 a.m. The plant did not start drawing power from the traditional source again until 2 p.m. Attached is a screen grab that shows the solar photovoltaic production for the day.
“This is a great example of what we can get to,” said David Driskell, executive director of Community Planning and Sustainability. “It shows it is possible to really change our energy mix, and that will have long-term economic and environmental benefits to us as a community.”
While going “off the grid” is impressive, the ultimate goal for the WWTF is for 50 percent or more of the facility’s power to come from alternative sources, over a monthly or annual basis, Douville said. The city hopes to meet this goal through a combination of energy efficiency efforts and maximizing its alternative supplies.
SOURCE: CITY OF BOULDER NEWS RELEASE