Posts tagged cause
Feed them and they will come…
Oct 19th
With bears foraging for food in preparation for their winter hibernation, it is important that residents take measures to deter bears by securing any potential food sources on their properties. See the Inside Boulder News segment about recent bear activity.
Bear-proofing food items and trash is the best way for residents to minimize the chance that bears will show interest in their property. Common bear attractants include garbage, compost, fruit from trees, bird feeders, food from outdoor grills and pet food left outside.
City regulations require that curbside garbage/compost bins not be placed out for pick up until 5 a.m. the day collection occurs. Alleyway bins are exempt from these regulations.
To be safe, the city recommends that residents west of Broadway store all garbage and compost bins in a garage or shed until the morning of collection, or keep their waste in a bear-resistant trash container. Residents within Boulder city limits can contact their trash hauler for specific information about bear-resistant trash containers.
Bears that learn that people are a source of food are sometimes killed to keep the public safe. During the past six years, Colorado Parks and Wildlife has killed five bears in Boulder because of nuisance behavior or a threat to public safety. Please do your part to ensure that bears are not unnecessarily attracted to your property.
If there is a bear in your backyard, the following tips are recommended:
- Keep your distance. Back away slowly from the bear, ensuring it has a clear escape path;
- Never run. Running may cause a bear to chase you;
- Never approach a bear, or get in between a cub and its mother;
- Never provide food to a bear. This teaches it to approach people for food;
- Do not let the bear become comfortable around your home; and
- Once you are safely inside, do your best to scare the bear away. Yell, clap your hands and make other loud noises to encourage the bear to leave.
If the bear is observed within the city limits, call the Boulder Police Department at 303-441-3333. To report past bear sightings and encounters, call 303-441-3004.
The city is currently conducting an Urban Black Bear Education and Enforcement Pilot Program in partnership with Colorado Parks and Wildlife. For more information about the pilot program, contact Urban Wildlife Conservation Coordinator Val Matheson at 303-441-3004 or visit www.boulderwildlifeplan.net.
For a detailed discussion about bears in the urban/foothill interface, watch the “Bears in Boulder” segment of A Boulder View.
To learn more about bears, visit www.osmp.org or the Colorado Division of Wildlife (DOW) website at: wildlife.state.co.us/bears.
Fourmile canyon blaze yields new insight into climate change, CU scientists say
Aug 27th
heat-trapping effects of wildfire smoke particles
When the Fourmile Canyon Fire erupted west of Boulder in 2010, smoke from the wildfire poured into parts of the city including a site housing scientists from the University of Colorado Boulder’s Cooperative Institute for Research in Environmental Sciences and the National Oceanic and Atmospheric Administration.
Within 24 hours, a few researchers at the David Skaggs Research Center had opened up a particle sampling port on the roof of the building and started pulling in smoky air for analysis by two custom instruments inside. They became the first scientists to directly measure and quantify some unique heat-trapping effects of wildfire smoke particles.
“For the first time we were able to measure these warming effects minute-by-minute as the fire progressed,” said CIRES scientist Dan Lack, lead author of the study published today in the Proceedings of the National Academy of Sciences.
The researchers also were able to record a phenomenon called the “lensing effect,” in which oils from the fire coat the soot particles and create a lens that focuses more light onto the particles. This can change the “radiative balance” in an area, sometimes leading to greater warming of the air and cooling of the surface.
While scientists had previously predicted such an effect and demonstrated it in laboratory experiments, the Boulder researchers were one of the first to directly measure the effect during an actual wildfire. Lack and his colleagues found that lensing increased the warming effect of soot by 50 to 70 percent.
“When the fire erupted on Labor Day, so many researchers came in to work to turn on instruments and start sampling that we practically had traffic jams on the road into the lab,” Lack said. “I think we all realized that although this was an unfortunate event, it might be the best opportunity to collect some unique data. It turned out to be the best dataset, perfectly suited to the new instrument we had developed.”
The instrument called a spectrophotometer can capture exquisite detail about all particles in the air, including characteristics that might affect the smoke particles’ tendency to absorb sunlight and warm their surroundings. While researchers know that overall, wildfire smoke can cause this lensing effect, the details have been difficult to quantify, in part because of sparse observations of particles from real-world fires.
Once the researchers began studying the data they collected during the fire, it became obvious that the soot from the wildfire was different in several key ways from soot produced by other sources — diesel engines, for example.
“When vegetation burns, it is not as efficient as a diesel engine, and that means some of the burning vegetation ends up as oils,” Lack said. In the smoke plume, the oils coated the soot particles and that microscopic sheen acted like a magnifying glass, focusing more light onto the soot particles and magnifying the warming of the surrounding air.
The researchers also discovered that the oils coating the soot were brown, and that dark coloration allowed further absorption of light, and therefore further warming the atmosphere around the smoke plume.
The additional warming effects mean greater heating of the atmosphere enveloped in dark smoke from a wildfire, and understanding that heating effect is important for understanding climate change, Lack said. The extra heating also can affect cloud formation, air turbulence, winds and even rainfall.
The discovery was made possible by state-of-the-art instruments developed by CIRES, NOAA and other scientists, Lack said. The instruments can capture fine-scale details about particles sent airborne by the fire, including their composition, shape, size, color and ability to absorb and reflect sunlight of various wavelengths.
“With such well-directed measurements, we can look at the warming effects of soot, the magnifying coating and the brown oils and see a much clearer, yet still smoky picture of the effect of forest fires on climate,” Lack said.
Wrap your mind around this! photo origami CU Boulder
Aug 27th
wins $2 million NSF grant
The art of origami has inspired children and artists all over the world because of the amazing objects that can be created by folding a simple piece of paper.
Now an engineering research team at the University of Colorado Boulder has won a $2 million grant from the National Science Foundation to develop a light-controlled approach for “self-assembly” mechanisms in advanced devices based on the same principles.
Known as “photo origami,” the idea is supported by NSF’s Emerging Frontiers in Research and Innovation program, which supports interdisciplinary teams working on rapidly advancing frontiers of fundamental engineering research.
CU-Boulder associate professor of mechanical engineering Jerry Qi will lead the team developing the photo origami technique. Collaborators will include CU faculty Robert McLeod of electrical engineering, Kurt Maute of aerospace engineering sciences and Elisabeth “Beth” Stade of mathematics, along with Patrick Mather of Syracuse University.
The ability to transform a flat polymer sheet into a sophisticated, mechanically robust 3-D structure will enable new approaches to manufacturing and design of devices from the microscopic to centimeter scales, according to the team. Examples include using extremely low-weight, high-strength materials to create micro-electromechanical systems with complicated 3-D architectures that can be used for microscopic sensors such as antennas or microphones, and miniature robotic devices for environmental monitoring.
Present barriers to the development of folding and unfolding mechanisms stem from the lack of understanding of scaling laws that allow researchers to generalize results obtained at various size scales, the inability to easily cause matter to “reorient” itself to achieve the desired folding patterns, and challenges in automated, sequential folding.
To overcome these challenges, the CU team will make use of recent fundamental advances in the control of polymer architecture through light-triggered chemical reactions.
“One has to accurately control how much deformation a material should have in order to obtain a precise folding angle and to determine where to fold or stop folding in order to avoid interference in the folding path and form the desired structure,” said McLeod, who will use the interaction of light with material deformation to develop optical waveguide transistors.
In this new form of logic circuit, light triggers the deformation of a soft polymer, which in turn switches the light on or off. In this way, the optical waveguide transistor will enable a structure to be pre-programmed with a folding pattern through a sequential set of switching events controlled by the shape of an origami sheet.
In recent years, CU researchers and their collaborators have made significant progress in using light to control and alter the structure of a polymer. They are able to both bend and stiffen polymer structures and to develop new, soft, shape-memory composite materials through photo-initiation techniques. Shape-memory composites are “smart” materials that have the ability to return from a temporary, deformed shape to their original shape when induced by a trigger.
In addition, the team will work with the local school district to provide research and educational opportunities for K-12 students and teachers.