A recording dual beam light-scattering photometer is described which permits kinetic studies involving changes in turbidity, and which is not, as are single photocell instruments, affected by the errors due to the attenuation of the scattered light within the turbid medium. With this method, a renewed study has been made of the physical changes occuring in actomyosin under the influence of ATP.

The purpose of this experiment is to understand the interaction of radiation and matter, and the application to radiation detection and shielding. The inverse square law of the distance is demonstrated with the gamma radiation from Co 60 preparation, the halfvalue thickness and absorption coefficient of various materials determined with the narrow beam system and the corresponding mass attenuat...

A direct method for the measurement of the optical attenuation coefficient and the scattering anisotropy parameter based on applying the extended Huygens-Fresnel principle to optical coherence tomography images of blood is demonstrated. The images are acquired with a low-power probing beam at the wavelength of 1300 nm. Values of 12.15 mm(-1) and 0.95 are found for the total attenuation coeffici...

The RSH SPECT scanner provides parallel-beam attenuated projections for a fully 3D acquisition geometry. The geometry can be represented by circles on the unit sphere of projection directions, one circle for each position of the detector head. Unlike most other fully 3D geometries this one is particularly challenging because there are no 2D subsets in the data. When no attenuation is present, i...

Conventional radiography produces a single image of an object by measuring the attenuation of an x-ray beam passing through it. When imaging weakly absorbing tissues, x-ray attenuation may be a suboptimal signature of disease-related information. In this paper we describe a new phase-sensitive imaging method, called multiple-image radiography (MIR), which is an improvement on a prior technique ...

In many domains of acoustic field propagation, such as medical ultrasound imaging, lithotripsy shock treatment, and underwater sonar, a realistic calculation of beam patterns requires treatment of the effects of diffraction from finite sources. Also, the mechanisms of loss and nonlinear effects within the medium are typically nonnegligible. The combination of diffraction, attenuation, and nonli...

Under the condition of first-order blooming, a parallel dielectric slab, which is inserted in the path of an obliquely incident p- or s-polarized light beam, introduces multiple discrete attenuation levels given by 1/3, 4/27, 4/243,...... in reflection and 4/9, 4/81, 4/729,...... in transmission. These attenuation levels are independent of the slab refractive index, incident p or s linear polar...

Waveform light detection and ranging (wLiDAR) records the entire backscattered signal of an emitted laser pulse, enabling deeper penetration through tree canopy. However, due to interactions (e.g. reflection, absorption, and transmission) within the canopy, the full proportion of emitted light may not reach the ground, resulting in an attenuated waveform. Correction of attenuation will result i...

We demonstrate how a natural rubidium vapor cell can efficiently filter out a pump beam that produces an Raman gain in the stimulated Raman process at the D2 line of Rb. We observe a Raman gain of at least 12 dB in Rb when the pump beam is detuned below the first transition in Rb, while being exactly on-resonance with the first transition in Rb. With a single pass through a second cell, we obse...

We show that periodic distributions of gain or losses on the wavelength scale allow managing spatial diffraction of light beams, with no index contrast. It has been recently predicted that such artificial periodic structures, analogous to Photonic Crystals (PhCs), would also hold the novel spatial beam propagation effects reported for PhCs such as subdiffraction propagation, self-collimation, s...