https://febs.onlinelibrary.wiley.com/doi/pdf/10.1016/0014-5793%2883%2980010-6

'Molten-globule state': a compact form of globular proteins with mobile side-chains.

A description is given of a method for calibrating photodetectors based on some characteristics of the statistics of the field of spontaneous parametric light scattering. A phenomenological theory of parametric scattering is used to demonstrate that photons are only emitted in pairs. It is shown that, in principle, a priori information on the two-photon character and directionality of parametrically scattered light can be used for absolute calibration of photodetectors operated both in the analog linear regime and in the discrete photoelectron pulse counting regime.

https://iopscience.iop.org/article/10.1070/QE1980v010n09ABEH010660/pdf

Use of two-photon light for absolute calibration of photoelectric detectors

Of the physical techniques available for the study of biopolymers and other macromolecular and colloidal systems, dynamic light scattering is, perhaps, the most fascinating. The very idea of extracting useful dynamical and structural information from random fluctuations in the intensity of light scattered from otherwise unperturbed equilibrium solutions1-3 seems, at first glance, almost too good to be true. Indeed, for fragile preparations that are prone to suffer undesirable fates at the slightest change in solution conditions, dynamic light scattering may be the perfect technique. It is nondestructive, relatively rapid, and typically requires only modest amounts of material. In routine applications, even on unfamiliar samples, the dust-removal procedure (either gravity flow Millipore ® filtration or low-speed centrifugation) requires 10 to 20 min, and determination of the translational diffusion coefficient to an accuracy of a few percent, or less, requires 5 min. Verification that the dynamical...

Dynamic light scattering of biopolymers and biocolloids.

Flail chest and pulmonary contusion.

Prompted by the need for various studies ranging from quantum information to foundations of quantum mechanics, we systematically study the possibility of the absolute calibration of analog photodetectors based on the properties of parametric amplifiers. Our results show that such a method can be effectively developed with interesting possible applications in metrology.

https://arxiv.org/pdf/quant-ph/0511093.pdf

Possibility of absolute calibration of analog detectors by using parametric downconversion: a systematic study

Solutions of polystyrene (Mw=1.0×107) in 2-butanone (ethyl methyl ketone), in a concentration range 0.1 mg cc−1 to 10 mg cc−1, were studied using Quasi-Elastic Light Scattering. The relation of diffusion-like fluctuations in highly concentrated polymer solutions (cooperative diffusion) to the internal motion of single polymers was explored. We observed that when the concentration of a solution was brought from a dilute region to a highly concentrated region, the Rayleigh line spectrum clearly showed that the internal motion had changed from intramolecular motion within a single polymer to cooperative diffusion. We also analyzed the relaxation time of the lowest mode of the internal motion of single polymers in terms of the bead and spring model.

/pdf/quasi-elastic-light-scattering-study-of-concentration-xmmlalxigw.pdf

Quasi-Elastic Light Scattering Study of Concentration Dependence of Diffusion and Internal Motion in Chain Polymers

A covariance function, VN (τ,σ), is introduced for the analysis of noises in photocurrent time‐correlation spectroscopy of scattered light. Its explicit forms under various measuring conditions are given and the characteristics and magnitudes of the noises are investigated. The distortion of a correlation function caused by the truncation of both upper and lower frequency ranges is examined. The reason for the absence of the so‐called aliasing error in a Gaussian‐photocurrent correlation measurement is given.

Analysis of noises in photocurrent time‐correlation spectroscopy of scattered light

A new method for the rapid investigation of sedimentation phenomena of fine particles is developed by using the force due to a vibrational acceleration. The small displacement of the particle with respect to the wall of the container, which is produced by the vibration, is measured by the interference between the light scattered by the particle and that of the cell wall. The interference is detected as a beat note in the scattered‐light intensity, and displayed as a time‐autocorrelation of the photocurrent, the analysis of which gives the sedimentation coefficient and the dispersion.

Izumi Nishio

Papers

Quasi-Elastic Light Scattering Study of Concentration Dependence of Diffusion and Internal Motion in Chain Polymers

Analysis of noises in photocurrent time‐correlation spectroscopy of scattered light

Rapid investigation of sedimentation phenomena by vibrational force field.