Speed of Sound in some common Solids Speed of sound in some common solids like aluminum, brass, concrete and ... Speed of sound in normal air is 343 m/s. In water the speed of sound is 1433 m/s. Sound velocity in some common solids are indicated in the table below: Sound Waves Make Liquids Levitate, Develop Better Drugs Liquids can levitate, thanks to the magic of science. Researchers at Argonne National Laboratory have designed a device, fittingly called acoustic levitator, that uses two speakers that generate sound waves in order to make small droplets of liquids float. The high-power sounds waves, which are imperceptible to the human ear, interfere with each other and create what's called a "standing wave," a place where liquids effectively get trapped and stand still. Researchers hope this experiment will help develop amorphous drugs. These type of drugs require a smaller dose to reach the desired effects, and thus have gentler side effects. Normally, however, drugs have a crystalline structure because it's harder to produce amorphous ones.
No magic show: Real-world levitation to inspire better pharmaceuticals It’s not a magic trick and it’s not sleight of hand – scientists really are using levitation to improve the drug development process, eventually yielding more effective pharmaceuticals with fewer side effects. Scientists at the U.S. Department of Energy’s (DOE) Argonne National Laboratory have discovered a way to use sound waves to levitate individual droplets of solutions containing different pharmaceuticals. waves - What characterizes a metallic sound, and why do metals have a metallic sound? Interestingly something sounding metallic has its origin in its dimensions rather than the material, and this effect is only amplified by the material. The character of perceived sound is mostly determined by the excited oscillations of an object, the so called modal structure. The modes of an object depend on the geometry. An approximately one-dimensional object like a long thin cylinder will have mode frequencies that come as integer multiples of a fundamental frequency. These can be easily grouped by our auditory cortex to result in a single tonal perception with a timbral character depending on the energy distribution in the vibrational modes. We call this frequency structure "harmonic".
Acoustic Levitation: Scientists Use Sound Make Objects Levitate Scientists have developed a sound generator so powerful its shock waves can stun, and even kill people. Another group of researchers have developed another unusual application for sound: a method of "acoustic levitation" that could help maintain colonies on Mars or the moon by using high-pitched sound waves to remove alien dust. Wired explains, Blasting a high-pitched noise from a tweeter into a pipe that focuses the sound waves can create enough pressure to lift troublesome alien dust off surfaces, according to a study published January in the Journal of the Acoustical Society of America. Extra-terrestrial missions have been plagued by dust and debris, which cling to rovers and astronauts because lunar and Martian environments lack the Earth's water or atmosphere that can displace the particles.
ROP « blog.zynamics.com I spent the last two days with a friend of mine, Frank Boldewin of reconstructer.org, analyzing the Adobe Reader/Flash 0-day that’s being exploited in the wild this week. We had received a sample of a malicious PDF file which exploits the still unpatched vulnerability (MD5: 721601bdbec57cb103a9717eeef0bfca) and it turned out more interesting than we had expected. Here is what we found: Part I: The PDF file The PDF file itself is rather large.
Primary Metallic Crystalline Structures Primary Metallic Crystalline Structures (BCC, FCC, HCP) As pointed out on the previous page, there are 14 different types of crystal unit cell structures or lattices are found in nature. However most metals and many other solids have unit cell structures described as body center cubic (bcc), face centered cubic (fcc) or Hexagonal Close Packed (hcp). Acoustic Levitation Of Stones Acoustic Levitation Of Stones by Bruce Cathie Monastery construction, Tibetan style 100 Websites To See Before You Die Here at Maximum PC, we've always done our fair share of website recommendation articles--including a couple of doozies from the past few years. And of course we're not the only ones who do this sort of article either; it's a proven popular format. But this year, we thought we'd mix things up a little bit. Rather than just focusing on what's services are popular, or which web apps will make you the most productive, we wanted to take a look at what's fun on the Internet. In that spirit, our February cover feature is going to be 100 Websites You Need to Visit Before You Die. These are sites that will either entertain you, educate you, or just plain blow your mind.
Article about Lattice Vibrations by The Free Dictionary one of the main types of internal motion of a solid, in which the constituent particles (atoms or molecules) oscillate about equilibrium positions—the lattice points. For example, lattice vibrations in the form of standing or traveling sound waves arise whenever a crystal is acted upon by an external force that varies over time. However, even in the absence of external influences a steady state of vibrations is established in a crystal that is in thermal equilibrium with its environment, just as a fixed distribution of atoms or molecules is established in a gas according to their rate of translatory motion. The nature of lattice vibrations depends on the symmetry of the crystal, the number of atoms in its unit cell, the type of chemical bond, and the type and concentration of the crystal defects. In the course of normal vibration all particles of the crystal oscillate about their own equilibrium positions with the same constant frequency ω, like simple harmonic oscillators. Figure 1.