Cone vibrator demonstration

Demonstration and class experiments of standing waves provide a key link to musical instruments and to an important principle of engineering design. Use a selection from these experiments to illustrate that standing waves are to be found in many situations. The waves are in general more complex than those on a cord, but certain features remain the same:. Practical Activity for Generating standing waves from transverse waves on a rope and from longitudinal waves on a slinky spring.

The purpose of this article is to provide an overview of ultrasound and MR elastography, including a glossary of relevant terminology, a classification of elastography techniques, and a discussion of their respective strengths and limitations. Elastography is an emerging technique for the noninvasive assessment of mechanical tissue properties. These techniques report metrics related to tissue stiffness, such as shear-wave speed, magnitude of the complex shear modulus, and the Young modulus. Imaging-based elastography is an emerging technology that uses imaging to noninvasively assess mechanical tissue properties. Elastography techniques have evolved significantly over the last 2 decades and have now been implemented on clinical ultrasound and MR systems [ 1 — 4 ].

The apparatus consists of a string and an oscillator to generate different frequencies. Students can even visually determine wavelength, period and amplitude of waves. A string undergoing transverse vibration illustrates many features common to all vibrating acoustic systems just like the vibrations of a violin or guitar string. To adjust the tension of the string, various amounts of mass can be placed in the tray that hangs off the side of a table or lab bench with the use of the included pulley.

This article was written by Hayley Macmillen and repurposed with permission from Refinery We've all read some iteration of the classic "What's in her purse? These behind-the-scenes looks at people's everyday essentials can be both informative and entertaining—and so we upped the ante by asking five women, straight and queer, partnered and not, ages 23 to 44, to show us what's inside their sex-toy drawers. Read on for their intimate thoughts on their most intimate accessories.