Uncategorized
- Physics
The Brazil nut effect gets more jumbled
New and puzzling evidence for why big particles bob to the top when mixtures of granular materials are shaken-the so-called Brazil nut effect-emerges from an experiment showing that even the air between grains plays a role.
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19041
I think this article ignored the major reason that large particles rise to the surface. The laws of inertia and momentum indicate that larger particles don’t react as quickly as smaller particles do at the end of each back-and-forth shake of the container. This means there is a force for relative motion between different-sized particles. […]
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18977
The occurrence of underflows or hyperpycnal currents originating from the mouth of the Salinas River should be no surprise, given the long-known riverine bathometric feature existing between the river and Monterey Canyon. The river has a high sediment load, so if these currents weren’t present, sediments from the Salinas River would settle on the continental […]
- Earth
Sediments Sink River’s Flow into Sea
Deep-sea observations of occasional sediment-rich plumes of fresh water dumped into the ocean by rivers suggest that such underflows may be a prime conveyor of pesticides, organic carbon, and various nutrients to the seafloor.
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From the November 14, 1931, issue
PHYSICISTS STUDY EFFECTS OF STRONG WINDS ON SKYSCRAPERS Another official government investigation is getting under way in Washington. The men involved in the new probe are studying a problem of vital concern to every city in America. The investigators working now are scientists, and their problem is to find out whether skyscrapers–including the 10- and […]
- Computing
Sneaky Calculations
The same communication system that brings you the Web page of your choice can be exploited to perform computations.
- Health & Medicine
Cholesterol enables nerve cells to connect
Neurons form connections with each other using cholesterol supplied by other brain cells called glia.
- Earth
EPA switchback on arsenic
On Oct. 31, the Environmental Protection Agency rescinded its March decision to rescind a proposed tougher limit on arsenic in drinking water and is now planning to implement the tougher limit of 10 parts per billion in 2006.
- Earth
Cancer risk linked to night shifts
Women who work the graveyard shift increase their chance of developing breast cancer, perhaps because of chronic suppression of melatonin.
- Chemistry
Foam gets its shot at anthrax
A recently developed chemical cocktail that kills anthrax spores and breaks down chemical warfare agents and anthrax has received its first real- world trials in anthrax cleanups.
- Chemistry
New sensor can ID dangerous bacteria
When newly created organic molecules, called TWTCPs, are attached to a porous silicon wafer and exposed to a certain class of bacterium, the wafer changes color.
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Leonardo’s Bridge
In 1502, Leonardo da Vinci made a simple drawing of a great, 240-meter bridge that was to span an inlet at the mouth of the Bosporus River in what is now Turkey. The bridge was never built, but Leonardo’s design has been reproduced in a wooden bridge for pedestrians over a highway in Norway. Artist […]
