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1

Diffuse reflectance spectroscopy for identification of carcinogen transformation stages in skin tissue

Shurrab Kawthar, Kochaji Nabil, Bachir Wesam

Polish Journal of Medical Physics and Engineering

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2019

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Vol. 25, Iss. 3

141--147

EN

Today, to establish a diagnosis, the patient must undergo a biopsy followed by histopathological diagnosis, which causes unnecessary cost, patient trauma, and time delay to obtain a diagnosis. However, the metastases can be discovered by diffuse reflectance spectroscopy, which is a simple method that investigates the light distribution within tissue. The theme of this paper is the use of diffuse reflectance spectroscopy (DRS) to determine the optical spectrum of hamster specimen’s tissue and to differentiate biological changes due to laser irradiation (scattering, and cell changes) under the skin. DRS measurements were made on healthy and malignant tissue to diagnose the stages of cancer formation using a fiber-optic probe. The results show that malignant tissue is characterized by a significant decrease in diffuse reflectance spectrum compared to normal tissue.

2

Improvement Optical and Electrical Characteristics of Thin Film Solar Cells Using Nanotechnology Techniques

Thabet Ahmed, Abdelhady Safaa, Ebnalwaled A.A., Ibrahim A. A.

International Journal of Electronics and Telecommunications

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2019

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Vol. 65, No. 4

625--634

EN

This work presents a theoretical study for the distribution of nanocomposite structure of plasmonic thin-film solar cells through the absorber layers. It can be reduced the material consumption and the cost of solar cell. Adding nanometallic fillers in the absorber layer has been improved optical, electrical characteristics and efficiency of traditional thin film solar cells (ITO /CdS/PbS/Al and SnO2/CdS/CdTe/Cu) models that using sub micro absorber layer. Also, this paper explains analysis of J-V, P-V and external quantum efficiency characteristics for nanocomposites thin film solar cell performance. Also, this paper presents the effect of increasing the concentration of nanofillers on the absorption, energy band gap and electron-hole generation rate of absorber layers and the effect of volume fraction on the energy conversion efficiency, fill factor, space charge region of the nanocomposites solar cells.

3

Electronic structure, first and second order physical properties of MPS4: a theoretical study

Dahame T., Bentria B., Faraoun H., Benghia A., Reshak A. H.

Materials Science Poland

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2016

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Vol. 34, No. 2

275--285

EN

We have calculated the electronic structure and physical properties of metal thiophosphate compounds InPS4 and AlPS 4by means of pseudopotential density functional theory (DFT) coupled with the modern theory of polarization. The targeted physical properties are ﬁrst and second order optical properties as well as elastic, piezoelectric and electro-optic coefﬁcients. Furthermore, population analysis is presented in order to evaluate the covalent-ionic character of the constituent bonds. The calculated elastic constants, refractive indices and second order optical coefﬁcients of InPS4 are in good agreement with experimental values. With the absence of any theoretical or experimental physical properties of AlPS4, we predict that this compound has high piezoelectric coefﬁcients with d14 = − 73.82 pm/V, d25 = − 10.96 pm/V and d36 = 28.19 pm/V.

4

Preparation and Optical Properties of PS @Au–Cu Core-Shell Nano Composite

Rudainah A., Farkad A., Lin Y.

International Letters of Chemistry, Physics and Astronomy

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2015

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Vol. 49

81--89

EN

An appropriate low-cost uncomplicated chemical method has been used to obtain the optical properties in the production of plasmon by manufacturing nanomaterial's consisting of dielectric core and a shell that grows on its surface . This core consists of the polystyrene PS and a gold – copper shell. The synthesis was made in two steps . In the first step PS core was fabricated , then coated by a shell consisting of Au –Cu particles . The shell shape differs according to the change in the amount of molar concentrations of Cu, and H2O2. It is found that variation of this materials amount gives us absorbance measurements (Localised Surface Plasmon Resonance, LSPR) that increase proportionally with changing quantities directly, where the size of core is constant .And the peak position in blue shift high energy then changes to red shift low energy . This change depends on the size and shape of particles. The same case applies for the transmittance of its change with the change of this material. The nano shell was characterized by using Scanning electron microscopy,SEM and UV –vis spectroscopy by varying the amount of Cu and H2O2.

5

Selection of optical to mography parameters for gas bubble shape analysis

Rząsa M.R.

Chemical and Process Engineering

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2014

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Vol. 35, nr 1

19--33

EN

An optical tomograph in which a tested object is illuminated from five directions has been presented in the paper. The measurements of luminous intensity after changing into discrete signals (0 or 1) in the detectors equipped with 64 optical sensors were subjected to reconstruction by means of the matrix algorithm. Detailed description of the measuring sensor, as well as the principles of operation of the electronic system, has been given in the paper. Optical phenomena occurring at the phase boundary while transmitted through the sensor wall and phenomena inside the measuring space have also been taken into account. The method of the sensor calibration has been analysed and a way of technical solution of the problem under consideration has been discussed. The elaborated method has been tested using objects of the known shape and dimensions. It was found that reconstruction of the shapes of moving bubbles and determination of their main parameters is also possible with a reasonable accuracy.

6

Optyczna metoda rekonstrukcji geometrii zębów – Focus Variation

Burek J., Bazan A., Płodzień M, Turek P.

Pomiary Automatyka Kontrola

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2013

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R. 59, nr 10

1133--1135

PL

W artykule przedstawiono innowacyjną i niezależną optyczną metodę pomiaru geometrii Focus Variation, jako alternatywę dla aktualnie stosowanych rozwiązań wykorzystywanych w pomiarach biomodeli. Opisana metoda pomiarowa, umożliwia rekonstrukcję obiektów o niewielkich gabarytach i o skomplikowanej geometrii powierzchni. Dokonano analizy dokładności wykonania rekonstrukcji geometrii na przykładzie koron zębów. Uzyskane wyniki w ponad 80 procentach mieszczą się w granicach +-71 μm co świadczy o przydatności metody w zastosowaniach dentystyczno-stomatologicznych.

EN

This paper describes the principle of operation of the focus variation method used for optical 3D measurements. The goal of investigations was to analyse the quality of surface reconstruction of the tooth crown geometry and the usefulness of the method in the dental industry. The focus variation method combines the small depth of focus of an optical system with vertical scanning to provide topographical and colour information resulting from the variation of focus [5]. Fig. 2 shows the schematic diagram of a measuring system based on the focus variation method. It is possi-ble to measure surface points with high trueness using coordinate measuring machines (CMMs). However, limitation in the scanning speed as well as not accurate enough measurement of freeform surfaces such as fissure lines and interproximal areas make the access of the measuring probe to these places impossible. The measurement inaccuracy is due to the geometric size and shape of the tip of the stylus (probe) [3]. The results of the report (Fig. 5) are satisfactory for modeling so small and complex surfaces which are free crowns of the teeth. The focus variation method introduces new, more accurate scanning capabilities of the premises used in the dental industry.

7

Knockdetection using spectral emission of flames

Piernikarski D.

Journal of KONES

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2009

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Vol. 16, No. 2

383-392

EN

Introduction of spectrophotometric methods into engine research considerably expands diagnostic possibilities of the work cycle in the internal combustion engine. Spectral analysis enables to determine concentrations of chemically active compounds - radicals, which are temporary present in the flame and do not constitute finał products of the combustion. The aim of the presented research was to investigate spectral properties of the combustion flame with special regard to the detection and estimation of intensity of knocking combustion. Research was made using modifled single cylinder si test engine equipped with an optical sensor having direct access to the combustion chamber. The sensor enabled on-line transmission of the transient optical signal during the combustion through the bundle of optical wave-guides. Measurements were based on the chemiluminescence phenomena occurring in the combustion flame under the influence of high temperature and pressure. Gathered signal was passed to the monochromator. Spectral recordings were done for wavelengths typical of emission of intermediate products, covering the range from 250 nm to 625 nm, including investigated radicals like C2, CH, CN, OH. Obtained results confirmed, that occurrence of knock can be precisely detected on the basis of signal analysis which was recorded for chemiluminescence traces of different radicals. Comparison with in parallel recorded indicated pressure have shown that characteristics of emitted spectra remain in good conformity and are more sensitive to the changing of engine operating conditions.

8

Ray tracing method in a 3D analysis of fiber-optic elements

Witkowski J.S., Grobelny A.

Optica Applicata

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2008

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Vol. 38, nr 2

281-294

EN

In this paper, a numerical analysis of algorithm of optical fiber systems with dimensions much larger than light wavelength has been presented. This algorithm can be used especially in the case of multimode fiber-optic elements. The presented technique of the analysis is based on the ray tracing method (RTM). Up to now, the RTM was widely used for an analysis of lens-systems. In this paper, a new possibility for this method in fiber optic elements analysis has been shown. The algorithm permits to determine thousands of ray traces simultaneously in a desired 3D area of an arbitrarily defined refractive index. This technique can be applied for a gradient index (GI), step index (SI) fibers, different types of optical couplers, etc. The algorithm has been extended to analyze dispersion properties and pulse shape evolution tracking along a fiber-optic system.

9

Numerical simulation of the transport of particles in electrophoretic displays

Bert T., De Smet H., Beunis F., Strubbe F.

Opto-Electronics Review

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2005

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Vol. 13, No. 4

281-286

EN

Electrophoretic image displays (EPIDs) are a major contestant in the search for electronic paper. Working prototypes have been demonstrated, however, full understanding of the internal physical properties is not achieved yet. In this article, we will present, for the first time, a complete set of formulae that make it possible to simulate the electrical and optical properties of EPIDs. Starting from a theoretical model, that was presented in a previous article, this article gives numerical and graphical results. The set of formulae that was used and their output helps us understand how particles are transported inside a pixel and how this leads to the electrical and optical properties of the display.