Full-text resources of PSJD and other databases are now available in the new Library of Science.
Visit https://bibliotekanauki.pl
Preferences help
Polish version English version Language
enabled [disable] Abstract
Number of results

Results found: 4

Number of results on page
first rewind previous Page / 1 next fast forward last

Search results

Search:
in the keywords:  optical parameters
help Sort By:

help Limit search:
first rewind previous Page / 1 next fast forward last
1
Content available remote

A Simple Method of Determining the Effective Attenuation Coefficient

100%
Domański G., Konarzewski B., Pawłowski Z., Zaremba K., Marzec J., Trybuła A., Kurjata R.
Polish Journal of Medical Physics And Engineering
|
2007
|
vol. 13
|
issue 1
1-12
EN
This paper presents a simple method of determining the effective attenuation coefficient from steady-state diffuse reflectance measurements.
2
Content available remote

The Use of the Monte Carlo Method to Determine Optical Parameters of Tissue

100%
Domański G., Konarzewski B., Pawłowski Z., Zaremba K., Marzec J., Trybuła A., Kurjata R.
Polish Journal of Medical Physics And Engineering
|
2007
|
vol. 13
|
issue 1
23-32
EN
The paper presents the use of the Monte Carlo method to determine the optical parameters of tissue from steady-state diffuse reflectance measurements.
3
Content available remote

Determination of optical parameters of pulp suspensions by time-resolved detection of photoacoustic signals and total diffuse reflectance measurements

75%
Zhao Z., Törmänen M., Myllylä R.
Open Physics
|
2010
|
vol. 8
|
issue 2
221-227
EN
Time-resolved photoacoustics were used to measure the optical parameters of pulp suspensions for the first time. Reconstructing stress distribution along the direction of the incident laser light allows the effective attenuation coefficient of these suspensions to be determined. Simultaneously, the total diffuse reflectance of the suspensions was measured by the same laser source. Based on the effective attenuation coefficient and total diffuse reflectance, the absorption and reduced scattering coefficients of pulp suspensions can be calculated. In this study, three kinds of pulp suspensions with different kappa number (2, 13, and 16), a measure of lignin content in pulp fibers, were diluted with water to make samples with a consistency range from 1% to 5%, and studied at 355 nm wavelength. The results showed that the optical coefficients were approximately proportional to pulp consistency; on the other hand, the absorption coefficient was linearly correlated with kappa number, but the reduced scattering coefficient was not. Therefore, by determining its optical parameters, it is possible to extract the consistency and kappa number of an unknown pulp suspension.
4
Content available remote

Impact of optical indices on particle size distribution of activated sludge measured by laser diffraction method

51%
Sochan A., Polakowski C., Łagód G.
|
|
issue 1
137-145
EN
The important factors that strongly influence the particle size distributions measured by the laser diffraction method are the optical parameters of the suspension (refractive index and absorption coefficient). Knowledge of the values of these parameters is necessary for Mie theory. Mie theory is applied for conversion of the intensity of light recorded on detectors into particle size distribution (PSD) of tested material. Both wastewater and activated sludge are mixtures of a variety of elements (mineral or organic, including living organisms). In practice, it is not possible to define clearly the values of the optical parameters, as the composition of the suspension changes over time. The aim of the study was to estimate the impact of assumed values of the optical parameters on particle size distributions obtained. The PSDs of suspensions sampled in different stages of wastewater treatment are the most reproducible when the following optical parameters are defined: absorption coefficients - 1.0 and the refractive index - 1.52.
PL
Czynnikami, które w istotny sposób wpływają na rozkłady granulometryczne wyznaczane za pomocą dyfrakcji laserowej, są parametry optyczne mierzonej zawiesiny (współczynnik załamania światła oraz współczynnik absorpcji). Znajomość wartości tych parametrów jest niezbędna przy zastosowaniu teorii Mie. Teoria Mie jest wykorzystywana do przeliczenia intensywności światła zmierzonego na detektorach na rozkład granulometryczny (PSD) badanego materiału. Zarówno ścieki, jak i osad czynny są mieszaninami bardzo różnych składników (mineralnych i organicznych, w tym żywych organizmów). W praktyce nie ma możliwości określenia rzeczywistych wartości parametrów optycznych mieszanin, tym bardziej, że ich skład zmienia się w czasie. Celem niniejszej pracy było określenie wpływu założonych wartości parametrów optycznych na uzyskiwane rozkłady granulometryczne. Rozkłady granulometryczne zawiesin pobranych na różnych etapach oczyszczania ścieków są najbardziej powtarzalne dla następujących wartości współczynników optycznych: współczynnika absorpcji - 1,0 i współczynnika załamania światła - 1,52.
first rewind previous Page / 1 next fast forward last
JavaScript is turned off in your web browser. Turn it on to take full advantage of this site, then refresh the page.