Measuring absorption coefficient of scattering liquids using a tube inside an integrating sphere.

A method for measuring the absorption coefficient μ of absorbing and scattering liquid samples is presented. The sample is injected into a small transparent tube mounted through an integrating sphere. Two models for determining the absorption coefficient using the relative optical output signal are described and validated using aqueous ink absorbers of 0.

Photoacoustic measurement of the Grüneisen parameter using an integrating sphere.

A method that uses an integrating sphere as a platform for photoacoustic measurement of the Grüneisen parameter Γ of absorbing liquids is developed. Derivation of a simple equation for determining Γ is presented. This equation only requires the voltage peak-to-peak value of the photoacoustic signal detected by a flat transducer and the relative energy of the incident light measured by a photodetector.

Effect of 38 h of total sleep deprivation on the waking EEG in women: sex differences.

38 h of sleep deprivation in women resulted in decreased alpha, increased theta and increased intrahemispheric correlation during rest and increased theta and reaction time during task. F3-O1 coherent activity was selectively decreased consistent with the role of sleep for recovery of frontal functions. Sleep deprivation effects were milder in women than in men, however, recovery was not complete suggesting that women need more sleep than men to recover.