Results 291 to 300 of about 29,191 (325)
Some of the next articles are maybe not open access.
Photoacoustic and Mirage Effect on Liquids
1990The temperature oscillation accompanying the photoacoustic effect (PAE) generates a periodic variation of vapor pressure P or the molar concentration χC in the transducer gas near the liquid surface /1/. Since χ is the mole fraction of the vapor and C the total concentration of the transducer gas, (1-χ)C is the molar concentration of the air in the ...
H. Schmitt +3 more
openaire +2 more sources
Photoacoustic effect in stressed elastic solids
Journal of Applied Physics, 2000A multimode approach based on the simultaneous application of several photothermal and photoacoustic methods is proposed for the study of thermal and thermoelastic effects in solids with residual stress. It includes photoacoustic gas microphone, photodeflection, photoreflectance and photoacoustic piezoelectric microscopy methods. This approach provides
J. E. Dumar +3 more
openaire +2 more sources
Photoacoustic effect in a sinusoidally modulated structure
Applied Physics Letters, 2012We derive solutions to an inhomogeneous Mathieu equation that describes the photoacoustic effect in a one-dimensional phononic structure whose acoustic properties vary sinusoidally in space. Solutions show splitting of resonances, the space equivalent of subharmonic generation, and spatial confinement.
Binbin Wu, Gerald J. Diebold
openaire +2 more sources
Light scattering effects in photoacoustic spectroscopy
Journal of Applied Physics, 1980The influence of light scattering on photoacoustic signals is treated. Theoretical and experimental results are compared. The theoretical results are based on a model in which the photons diffuse through the sample. An equation governing the diffusion process is solved with appropriate boundary conditions.
Per Helander +2 more
openaire +2 more sources
Biomass monitoring using the photoacoustic effect
Sensors and Actuators B: Chemical, 1998Abstract Photoacoustic spectroscopy was evaluated as useful for the determination of the number of cells in a fermentation. The influence of scattering particles and gas bubbles on the measurement was investigated. The photoacoustic method is much less influenced by scattering particles than the turbidity method.
Dieter Beckmann, Kai Schmidt
openaire +2 more sources
Detection of ferromagnetic resonance by photoacoustic effect
Applied Physics Letters, 1979By exploring the simple periodic heat-flux principle of the photoacoustic cell we propose and demonstrate experimentally the usefulness of the photoacoustic cell for studying the ferromagnetic resonance. An interesting feature of this technique is that it offers special advantages over conventional spectroscopic methods used in ferromagnetic resonance ...
O. A. Cleves Nunes +2 more
openaire +2 more sources
Thermal contact probing by photoacoustic effect
Applied Physics Letters, 1981The influence on the photoacoustic signal of the thermal contact resistance at the interface sample substrate is investigated using a thin metallic foil (thickness ∼12.5 μm) as sample. The foil is either applied by pressure against the substrate or epoxyed on it.
L. Bertrand +3 more
openaire +2 more sources
Photoacoustic spectra and photovoltaic effect of flavins
Biochimica et Biophysica Acta (BBA) - General Subjects, 1985Abstract Photoacoustic spectra and the kinetics of the photovoltaic effect, as well as action spectra of 10-formylmethylisoalloxazine, riboflavin, flavomononucleotide and the complexes of flavins with riboflavin-bound proteins, were measured. The spectral regions of high efficiency of thermal deactivation of flavin excitation were observed.
Surat Hotchandani +4 more
openaire +2 more sources
Needle visualization using photoacoustic effect
SPIE Proceedings, 2015We investigated a novel needle visualization using the PA effect to enhance needle-tip tracking. An optical fiber and laser source are used to generate acoustic waves inside the needle with the PA effect. Acoustic waves are generated along the needle. Some amount of acoustic energy leaks into the surrounding material.
Alexis Cheng +4 more
openaire +2 more sources
Thermodynamic Models of the Photoacoustic Effect
1984The source of the acoustic signal is the heat, in whatever manner it may be created from the energy of light absorbed by the sample. The whole process, beginning with the created heat eQ and ending when the pressure signal eP arrives at the acoustical detector, can be described using the formalism of thermodynamics.
openaire +2 more sources