Tala Ko

Archive for May 2009

clipped from www.nytimes.com
To understand what is really going on in a colony of ants or bees, Dr. Dornhaus, an assistant professor of ecology and evolutionary biology at the University of Arizona, tracks the little creatures individually — hence the paint and the numbers.

studies of whether the efficiency of ant society, based on a division of labor among ant specialists, is important to their success
briefly anesthetized 1,200 ants, one by one, and painted them using a single wire-size brush, with model airplane paint
two video cameras aiming down on an insect-size stage, she analyzed 300 hours of videotape of the ants in action
behavior more worthy of Aesop’s grasshopper than the proverbial industrious ants
fast ants took one to five minutes to perform a task
slow ants took more than an hour, and sometimes two
about 50 percent of the other ants do not do any work at all
small colonies may sometimes rely on a single hyperactive overachiever
  blog it
Advertisements
clipped from news.nationalgeographic.com


Traditional concrete is brittle and is easily fractured during an earthquake or by overuse.


By contrast, the new concrete composite can bend into a U-shape without breaking. When strained, the material forms hairline cracks, which auto-seal after a few days of light rain.


Dry material exposed by the cracks reacts with rainwater and carbon dioxide in the air to form “scars” of calcium carbonate, a strong compound found naturally in seashells, said study co-author Victor Li of the University of Michigan in Ann Arbor.

bendable concrete picture


Although it costs three times as much as traditional concrete, the material is a cost-saver in the long run, due to its reduced maintenance needs and energy demands, Li said.

  blog it