Search results for "LIGHT"

On the Measurement and Prediction of the Out-of-Plane Displacement Surrounding Cold-Expanded Holes

2010

Experimental measurements of the out-of-plane displacement surrounding cold-expanded holes in a 6082-T6 aluminum alloy were made with a 3D optical scanner using the technique of the encoded light-pattern projection in white light. The measured surface profiles have shown the thickness discontinuity along the hole edge due to the effect of the split in the sleeve. An analytical–numerical solution of the out-of-plane displacement is presented based on existing analytical models. Thus, the results given by the analytical model were then compared with the experimental data and with a finite element (FE) model that simulates the cold-expansion process. The location of the elastic–plastic boundar…

Characterisation of two new radiochromic gel dosimeters TruView™ and ClearView™ in combination with the vista™ optical CT scanner: A feasibility study

2018

This study aims at characterising the properties of TruView™ and ClearView™ two new gel dosimeters (Modus Medical Devices Inc.) and at studying the feasibility of relative dosimetry using these dosimeters and the Vista™ Optical CT scanner to accurately evaluate dose.In this work, we investigated key dosimetric aspects (dose response, energy and dose rate dependence) and stability of these radiochromic gels initiated in preliminary works (Huet et al., 2017; Colnot et al., 2017) using spectrophotometric measurements. Moreover, by mean of optical CT scanning (Vista™), their performances to measure relative depth dose (PDD) and cross profiles were analysed.TruView™ and ClearView™ present a line…

Reflection scanning microscopy.

1992

To image nontransparent samples we have utilized a special type of scanning-probe microscope that is referred to here as a reflection scanning microscope. The reflection scanning microscope provides a method for producing a scanned point light source as well as a system for collecting the light that is reflected by the sample. The system, which uses an optical fiber coupler, is easily installed on an existing photon scanning tunneling microscope. A calculation of the coupling coefficient between the natural propagation mode of the optical fiber and the light that is reflected by the sample is presented along with a comparison between calculated and measured values of the intensity of the li…

Competition between heterogeneous and homogeneous nucleation near a flat wall

2009

We studied the competition between heterogeneous and homogeneous nucleation of an aqueous suspension of charged colloidal spheres close to the container walls. Samples of equilibrium crystalline structure were shear-melted and the metastable melt left to solidify after the cessation of shear. The crystallization kinetics was monitored using time-resolved scattering techniques: at low particle number densities n we applied an improved static light scattering method while at large particle concentrations ultra-small-angle x-ray scattering was applied for the first time. Our results show some unexpected behavior: the heterogeneous nucleation at the container walls is delayed in comparison to t…

Particle Characterization Using Multiple Scattering Decorrelation Methods. Part 1: Standard Latex Particles

1999

A light-scattering photometer for use at elevated pressures

1970

A new light scattering photometer has been designed in order to perform light-scattering measurements at various temperatures and under pressures of 1–1000 atm. Since the scattering angle is constant (90°C), the dimensions of the dissolved molecules are determined by measuring the intensity at different wavelengths. The method of measurement, the calibration of the instrument, and the treatment of data are described. By a series of test measurements on polystyrene in trans-decalin solutions it is shown that one obtains reliable results and finds considerable effects of pressure on the radius of gyration and the fundamental thermodynamic properties of the system.

Population dynamics and ecology of subdominant phytoplankton species in a shallow hypertrophic lake (Albufera of Valencia, Spain)

1994

Long-term population dynamics and ecology of the abundant but non-dominant phytoplankton species of the shallow hypertrophic lake the Albufera of Valencia (Spain) are described for the period 1980–1988. The lake is used as a reservoir for the surrounding ricefield cultivation. It is continuously dominated by three filamentous blue-green algae, Planktothrix agardhii, Pseudanabaena galeata and Geitlerinema sp. Horizontal differences of the phytoplankton were less important than annual and seasonal variations. An annual increasing trend was observed for Planktolyngbya subtilis, Planktolyngbya contorta, Cylindrospermopsis raciborskii, Microcystis incerta, Nitzschia palea var. tenuirostris and R…

A Dynamic Attribute-Based Authentication Scheme

2015

Attribute-based authentication (ABA) is an approach to authenticate users by their attributes, so that users can get authenticated anonymously and their privacy can be protected. In ABA schemes, required attributes are represented by attribute trees, which can be combined with signature schemes to construct ABA schemes. Most attribute trees are built from top to down and can not change with attribute requirement changes. In this paper, we propose an ABA scheme based on down-to-top built attribute trees or dynamic attribute trees, which can change when attribute requirements change. Therefore, the proposed dynamic ABA scheme is more efficient in a dynamic environment by avoiding regenerating…

Use of balanced detection in single-pixel imaging

2016

We introduce balanced detection in combination with simultaneous complementary illumination in a single-pixel architecture. With this novel detection scheme we are able to recover a real-time video stream in presence of ambient light.

Technical‐economic evaluation of the effectiveness of measures applied to the artificial lighting system of a school

2021

Ensuring optimum interior lighting is a topic of great importance, as this influences not only the well-being of users but also the optimal performance of visual tasks. Lighting can be natural, but if not sufficient, it can be compensated with artificial lighting. This study highlights a methodology for designing a new lighting system that takes into account both technical and economic aspects. The method was applied to an existing school located in southern Italy, in which the electricity consumption is related to the current lighting system. The school is chosen as being representative of the construction type and layout of many local schools. In addition, the coexistence of several visua…