Photoacoustic imaging is a state-of-the-art technique that combines light excitation with ultrasound generation via the photoacoustic effect. Since sound waves at clinically relevant frequencies undergo minimal perturbation as they pass through the body, photoacoustic imaging is ideal for deep-tissue imaging applications in vivo. Despite its…

The acoustic resonance in four glass Helmholtz resonators with diameters of 70, 52, 40, and 32 mm was detected in the frequency range of 360 to 1700 Hz using the simple experimental setup presented in this paper. The measured amplitudes of acoustic pressure required correction since the sound pressure amplitude of the loudspeaker used was not…

We present a modernization of the undergraduate physical chemistry laboratory experiment for determining the speed of sound in various gases from resonant frequencies in a spherical resonator. The resonator (schematic IR = 7.5 cm) is constructed by 3D printing with eco-friendly poly(lactic acid), a commercially viable alternative to traditional…

These days, smartphones are popular commodities among students in high school and college. Students carry their devices all the time, so why not use such a popular electronic device to measure physical quantities such as "g" in physics labs? In this work, we report a "multiple tasking" method, a measurement technique that we…

To study the absorption of ultrasound in plexiglas we propose to use gadgets that are available to each student: an ultrasound humidifier, a liquid crystal display of a pad, a polaroid analyzer, a digital camera, a multimeter with thermocouple, and a stopwatch. These devices allow us to visualize a region in plexiglas where ultrasound is absorbed…

Laboratory report assignments for non-major and introductory classes can be challenging because the students are unfamiliar with the type of technical writing required and the subject matter. These issues for the student make the grading for the instructor difficult and time consuming. Determining the level of detail to require, the format, and…

The labs presented here build on a simple speed of sound activity and models medical ultrasound imaging by demonstrating how multiple reflections propagate in a closed system. A short sound pulse is emitted into a pipe that is closed at one end and contains one or more partially reflecting surfaces within the pipe. The variety of reflections and…

Quantum mechanics is a notoriously difficult subject to learn, due to a lack of real-world analogies that might help provide an intuitive grasp of the underlying ideas. Discrete energy levels and absorption and emission wavelengths in atoms are sometimes described as uniquely quantum phenomena, but are actually general to spatially confined waves…

Recently devices such as the optical mouse of a computer, webcams, Wii remote, and digital cameras have been used to record and analyze different physical phenomena quantitatively. Devices like tablets and smartphones are also becoming popular. Different scientific applications available at Google Play (Android devices) or the App Store (iOS…

The noise level from exploding chemical demonstrations and the effect they could have on audiences, especially young children, needs attention. Auditory risk from H[subscript 2]- O2 balloon explosions have been studied, but no studies have been done on H[subscript 2]-air "eggsplosions." The peak sound pressure level (SPL) was measured…

The resonance phenomenon is widely known in physics courses. Qualitatively speaking, resonance takes place in a driven oscillating system whenever the frequency approaches the natural frequency, resulting in maximal oscillatory amplitude. Very closely related to resonance is the phenomenon of mechanical beating, which occurs when the driving and…

In the present paper we suggest an original physical explanatory model that explains the mechanism of the sound amplification process in a stethoscope. We discuss the amplification of a single pulse, a continuous wave of certain frequency, and finally we address the resonant frequencies. It is our belief that this model may provide students with…

In this paper, we describe an experiment for the undergraduate physical chemistry laboratory in which students determine the speed of sound in the gases He, N[subscript 2], CO[subscript 2], and CF[subscript 3]CH[subscript 2]F. The experimental apparatus consists of a closed acrylic tube containing the gas under study. White audio noise is injected…

Nowadays, the use of data-acquisition systems in undergraduate laboratories is routine. Many computer-assisted experiments became possible with the PASCO scientific data-acquisition system based on the 750 Interface and DataStudio software. A new data-acquisition system developed by PASCO includes the 850 Universal Interface and Capstone software.…

Measuring the heat capacity ratios, [gamma], of gases either through adiabatic expansion or sound velocity is a well established physical chemistry experiment. The most accurate experiments depend on an exact determination of sound origin, which necessitates the use of lasers or a wave generator, where time zero is based on an electrical trigger.…