Abstract Ho3+ ions doped tellurite-borate glass samples with varying compositions were prepared. ... more Abstract Ho3+ ions doped tellurite-borate glass samples with varying compositions were prepared. The compositional dependence on phenomenological Judd-Ofelt parameters was compared in different kinds of rare earth ions doped tellurite-borate glasses. Two methods were used to obtain radiative transition probability of 5I7 level with the aim of assuring the fitting quality. The integral absorption cross-sections and line shapes corresponding to 5I8→5G6 and 5I8→5I7 transition of Ho3+ ions were investigated in tellurite-borate glasses. The obtained data indicated that the integral absorption cross-sections corresponding to 5I8→5G6 transition of Ho3+ ions mainly depended on phenomenological Judd-Ofelt parameter, Ω2, because 5I8→5G6 transition belonged to hypersensitive transitions, which led to a larger Ω2 value. The change of line shapes of absorption spectra corresponding to 5I8→5G6 and 5I8→5I7 transitions of Ho3+ ions came from the lower energy regions, which could be attributed to the changed distribution of Stark levels and thermal population.
A series of green emitting Gd2O3:Tb3+ (Tb: 0%–10% mol) nanoparticles (NP) were synthesized using ... more A series of green emitting Gd2O3:Tb3+ (Tb: 0%–10% mol) nanoparticles (NP) were synthesized using the hydrothermal method, then characterized and evaluated for latent fingerprint visualization. X-ray diffraction study (XRD) revealed a cubic structure of the nanoparticles and the total incorporation of the terbium in the Gd2O3 matrix. Field Emission-Scanning Electron Microscopy (FESEM), Energy Dispersive x-ray Spectrometry (EDX) and Transmission Electron Microscopy (TEM) were used to study the morphology and the elementary composition of the NP. Photoluminescence (PL) studies showed strong green emission around 540 nm due to the transition 5D4 → 7F5. The luminescence color of the synthesized NP was characterized by the CIE 1931 chromaticity diagram. The potential use of the NP powders for the visualization of latent fingerprint under UV irradiation was assessed on various substrates. The latent fingerprint images revealed by the Gd2O3:Tb3+ NP powders are clear enough to extract and analyze reliable fingerprint features. The fingerprint quality was evaluated using three fingerprint quality assessment metrics and by extracting and measuring the visibility of the minutiae. The experimental results show very good quality images of the latent fingerprint acquired using the Gd2O3:Tb3+ NP and yield good minutiae extraction.
Fitting optical properties of metals is of great interest for numerical methods in electromagneti... more Fitting optical properties of metals is of great interest for numerical methods in electromagnetism, especially finite difference time domain (FDTD). However, this is a tedious task given that theoretical models used usually fail to interlink perfectly with the experimental data. However, in this paper, we propose a method for fitting the relative permittivity of metals by a sum of Drude-Lorentz or a sum of partial-fraction models. We use the particle swarm optimization (PSO) hybridized either with Nelder-Mead downhill simplex, or with gradient method. The main electronic transitions in metals help to guide the fitting process toward the solution. The method is automatic and applied blindly to silver, gold, copper, aluminum, chromium, platinum, and titanium.
Abstract Er3+ doped, Yb3+ doped, and Er3+/Yb3+ co-doped Y2Ti2O7 phosphors with various concentrat... more Abstract Er3+ doped, Yb3+ doped, and Er3+/Yb3+ co-doped Y2Ti2O7 phosphors with various concentrations of Er3+ (12–20%), Yb3+ (1-10 at%), and Er3+Yb3+ (1%, and 1,2,3%, respectively) were prepared by solid-state reaction. The phase structure and purity of all prepared phosphors were studied by X-ray diffraction analysis followed by measurement of the hydrodynamic diameter of each sample by Dynamic light scattering. The formation of the pyrochlore structure was confirmed by the observation of relative vibrations by Fourier Transform Infrared Spectroscopy. Moreover, photoluminescence spectra of different co-doped Y2Ti2O7 compounds are presented to check the energy transfer processes of Er3+ and Yb3+ ions. Finally, phosphors were used for the detection of latent fingermarks on various surfaces and a fingerprint minutia extraction algorithm was used for the analysis of extracted minutiae. The analyses confirm that the co-doped phosphors can be useful for the visualization of latent fingerprints once a good detection of their minutiae is obtained.
ABSTRACT Abstract In this paper, a new tellurite glass (85TeO2·5.0Nb2O5· 5.0ZnO·5.0LiF) doped wit... more ABSTRACT Abstract In this paper, a new tellurite glass (85TeO2·5.0Nb2O5· 5.0ZnO·5.0LiF) doped with 1 mol% Tm2O3 was prepared by melt-quenching technique. Differential scanning calorimetry (DSC) measurements indicate a good thermal stability, X-ray diffraction patterns show no sign of crystallization. Precise refractive index measurements were performed on five different wavelengths by a prism spectrometer. The optical energy gap, the Sellmeier energy gap and the dispersion energy were estimated. Judd–Ofelt intensity parameters were evaluated in order to obtain electric and magnetic-dipole transition probabilities, branching ratios and radiative lifetimes of several excited states of Tm3+. The classical McCumber theory was used to evaluate the emission cross-sections for the 3F4→3H6 transition at a wavelength of around 1.8 µm. The characteristics of down-conversion luminescence in the visible range were studied by exciting Tm3+ ions into the 1G4 level. Furthermore the structure of this glass was analyzed by Raman spectroscopy.
Engineering Sciences for Biology and Medicine (ESBM) is an exciting platform for researchers to d... more Engineering Sciences for Biology and Medicine (ESBM) is an exciting platform for researchers to discuss a wide range of modern biology and medicine goals. The third edition ESBM 2017 conference was organized by the Tunisian Association of Academic Researchers ATCU, in collaboration with the Technopark of Sfax and the Digital Research Centre of Sfax from May 4–7’ 2017 in Sfax, Tunisia. This conference encourages the scientific interactions among researchers to share their ideas and approaches on all aspects of glitches in biology and medicine. Editors thank all the participants for their contributions, that are greatly appreciated. This special section consists of selected peer-reviewed papers on 1) Nanobiotechnology and Nanomedicine, 2) Systems Biology and Forensics, 3) Health Data & Models, 4) Health Data Processing, 5) Devices, Infrastructure & Communication, and 6) e-Health Services and Applications that highlight current developments. The ESBM 2017 conference received a total of...
Submission Deadline 30/01/2015 Call for papers ESBM 2015 The international conference " Engi... more Submission Deadline 30/01/2015 Call for papers ESBM 2015 The international conference " Engineering Sciences in Biology and Medicine" ESBM'2015 will be organized in Monastir- Tunisia from 01 to 03 Mai 2015. You are invited to submit your abstract by 30 January 2015. Selected high quality research papers will be considered for publication after peer review in a special issue of the following journals: Advanced Science Letters (IF= 1.253) IEEE Transactions on NanoBioscience (IF= 1.768) For more details visit the conference website: http://www.esbm2015.com/
Journal of Photochemistry and Photobiology A Chemistry
New photoluminescent, non-toxic europium doped yttrium titanate phosphors (x mol% Eu3+/Y2Ti2O7 wh... more New photoluminescent, non-toxic europium doped yttrium titanate phosphors (x mol% Eu3+/Y2Ti2O7 where x = 1.0, 2.0, 4.0 6.0, 10, 15 and 30 mol%) with high crystalline structure were synthesized by sol–gel followed by heat treatment at 1000 °C for 5 h. Eu3+/Y2Ti2O7 phosphors were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), energy dispersive spectroscopy (EDS), FT-IR and photoluminescence (PL) spectroscopy. The effects of heat treatment and europium metal ion concentration on the structure and PL properties were investigated. Eu3+/Y2Ti2O7 phosphors exhibited micro spherical shape with average crystal size from 90 to 144 nm. The PL spectra showed the orange red emission bands of Eu3+ in highly symmetrical host. The longest PL lifetime was detected at 4 mol% Eu3+/Y2Ti2O7 phosphor. The toxicity of 15 mol% Eu3+:Y2Ti2O7 was tested. The obtained result showed LD50 is 3.2 g/kg. The PL and toxicity properties of the prepared phosphors make them promising m...
Abstract Ho3+ ions doped tellurite-borate glass samples with varying compositions were prepared. ... more Abstract Ho3+ ions doped tellurite-borate glass samples with varying compositions were prepared. The compositional dependence on phenomenological Judd-Ofelt parameters was compared in different kinds of rare earth ions doped tellurite-borate glasses. Two methods were used to obtain radiative transition probability of 5I7 level with the aim of assuring the fitting quality. The integral absorption cross-sections and line shapes corresponding to 5I8→5G6 and 5I8→5I7 transition of Ho3+ ions were investigated in tellurite-borate glasses. The obtained data indicated that the integral absorption cross-sections corresponding to 5I8→5G6 transition of Ho3+ ions mainly depended on phenomenological Judd-Ofelt parameter, Ω2, because 5I8→5G6 transition belonged to hypersensitive transitions, which led to a larger Ω2 value. The change of line shapes of absorption spectra corresponding to 5I8→5G6 and 5I8→5I7 transitions of Ho3+ ions came from the lower energy regions, which could be attributed to the changed distribution of Stark levels and thermal population.
A series of green emitting Gd2O3:Tb3+ (Tb: 0%–10% mol) nanoparticles (NP) were synthesized using ... more A series of green emitting Gd2O3:Tb3+ (Tb: 0%–10% mol) nanoparticles (NP) were synthesized using the hydrothermal method, then characterized and evaluated for latent fingerprint visualization. X-ray diffraction study (XRD) revealed a cubic structure of the nanoparticles and the total incorporation of the terbium in the Gd2O3 matrix. Field Emission-Scanning Electron Microscopy (FESEM), Energy Dispersive x-ray Spectrometry (EDX) and Transmission Electron Microscopy (TEM) were used to study the morphology and the elementary composition of the NP. Photoluminescence (PL) studies showed strong green emission around 540 nm due to the transition 5D4 → 7F5. The luminescence color of the synthesized NP was characterized by the CIE 1931 chromaticity diagram. The potential use of the NP powders for the visualization of latent fingerprint under UV irradiation was assessed on various substrates. The latent fingerprint images revealed by the Gd2O3:Tb3+ NP powders are clear enough to extract and analyze reliable fingerprint features. The fingerprint quality was evaluated using three fingerprint quality assessment metrics and by extracting and measuring the visibility of the minutiae. The experimental results show very good quality images of the latent fingerprint acquired using the Gd2O3:Tb3+ NP and yield good minutiae extraction.
Fitting optical properties of metals is of great interest for numerical methods in electromagneti... more Fitting optical properties of metals is of great interest for numerical methods in electromagnetism, especially finite difference time domain (FDTD). However, this is a tedious task given that theoretical models used usually fail to interlink perfectly with the experimental data. However, in this paper, we propose a method for fitting the relative permittivity of metals by a sum of Drude-Lorentz or a sum of partial-fraction models. We use the particle swarm optimization (PSO) hybridized either with Nelder-Mead downhill simplex, or with gradient method. The main electronic transitions in metals help to guide the fitting process toward the solution. The method is automatic and applied blindly to silver, gold, copper, aluminum, chromium, platinum, and titanium.
Abstract Er3+ doped, Yb3+ doped, and Er3+/Yb3+ co-doped Y2Ti2O7 phosphors with various concentrat... more Abstract Er3+ doped, Yb3+ doped, and Er3+/Yb3+ co-doped Y2Ti2O7 phosphors with various concentrations of Er3+ (12–20%), Yb3+ (1-10 at%), and Er3+Yb3+ (1%, and 1,2,3%, respectively) were prepared by solid-state reaction. The phase structure and purity of all prepared phosphors were studied by X-ray diffraction analysis followed by measurement of the hydrodynamic diameter of each sample by Dynamic light scattering. The formation of the pyrochlore structure was confirmed by the observation of relative vibrations by Fourier Transform Infrared Spectroscopy. Moreover, photoluminescence spectra of different co-doped Y2Ti2O7 compounds are presented to check the energy transfer processes of Er3+ and Yb3+ ions. Finally, phosphors were used for the detection of latent fingermarks on various surfaces and a fingerprint minutia extraction algorithm was used for the analysis of extracted minutiae. The analyses confirm that the co-doped phosphors can be useful for the visualization of latent fingerprints once a good detection of their minutiae is obtained.
ABSTRACT Abstract In this paper, a new tellurite glass (85TeO2·5.0Nb2O5· 5.0ZnO·5.0LiF) doped wit... more ABSTRACT Abstract In this paper, a new tellurite glass (85TeO2·5.0Nb2O5· 5.0ZnO·5.0LiF) doped with 1 mol% Tm2O3 was prepared by melt-quenching technique. Differential scanning calorimetry (DSC) measurements indicate a good thermal stability, X-ray diffraction patterns show no sign of crystallization. Precise refractive index measurements were performed on five different wavelengths by a prism spectrometer. The optical energy gap, the Sellmeier energy gap and the dispersion energy were estimated. Judd–Ofelt intensity parameters were evaluated in order to obtain electric and magnetic-dipole transition probabilities, branching ratios and radiative lifetimes of several excited states of Tm3+. The classical McCumber theory was used to evaluate the emission cross-sections for the 3F4→3H6 transition at a wavelength of around 1.8 µm. The characteristics of down-conversion luminescence in the visible range were studied by exciting Tm3+ ions into the 1G4 level. Furthermore the structure of this glass was analyzed by Raman spectroscopy.
Engineering Sciences for Biology and Medicine (ESBM) is an exciting platform for researchers to d... more Engineering Sciences for Biology and Medicine (ESBM) is an exciting platform for researchers to discuss a wide range of modern biology and medicine goals. The third edition ESBM 2017 conference was organized by the Tunisian Association of Academic Researchers ATCU, in collaboration with the Technopark of Sfax and the Digital Research Centre of Sfax from May 4–7’ 2017 in Sfax, Tunisia. This conference encourages the scientific interactions among researchers to share their ideas and approaches on all aspects of glitches in biology and medicine. Editors thank all the participants for their contributions, that are greatly appreciated. This special section consists of selected peer-reviewed papers on 1) Nanobiotechnology and Nanomedicine, 2) Systems Biology and Forensics, 3) Health Data & Models, 4) Health Data Processing, 5) Devices, Infrastructure & Communication, and 6) e-Health Services and Applications that highlight current developments. The ESBM 2017 conference received a total of...
Submission Deadline 30/01/2015 Call for papers ESBM 2015 The international conference " Engi... more Submission Deadline 30/01/2015 Call for papers ESBM 2015 The international conference " Engineering Sciences in Biology and Medicine" ESBM'2015 will be organized in Monastir- Tunisia from 01 to 03 Mai 2015. You are invited to submit your abstract by 30 January 2015. Selected high quality research papers will be considered for publication after peer review in a special issue of the following journals: Advanced Science Letters (IF= 1.253) IEEE Transactions on NanoBioscience (IF= 1.768) For more details visit the conference website: http://www.esbm2015.com/
Journal of Photochemistry and Photobiology A Chemistry
New photoluminescent, non-toxic europium doped yttrium titanate phosphors (x mol% Eu3+/Y2Ti2O7 wh... more New photoluminescent, non-toxic europium doped yttrium titanate phosphors (x mol% Eu3+/Y2Ti2O7 where x = 1.0, 2.0, 4.0 6.0, 10, 15 and 30 mol%) with high crystalline structure were synthesized by sol–gel followed by heat treatment at 1000 °C for 5 h. Eu3+/Y2Ti2O7 phosphors were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), energy dispersive spectroscopy (EDS), FT-IR and photoluminescence (PL) spectroscopy. The effects of heat treatment and europium metal ion concentration on the structure and PL properties were investigated. Eu3+/Y2Ti2O7 phosphors exhibited micro spherical shape with average crystal size from 90 to 144 nm. The PL spectra showed the orange red emission bands of Eu3+ in highly symmetrical host. The longest PL lifetime was detected at 4 mol% Eu3+/Y2Ti2O7 phosphor. The toxicity of 15 mol% Eu3+:Y2Ti2O7 was tested. The obtained result showed LD50 is 3.2 g/kg. The PL and toxicity properties of the prepared phosphors make them promising m...
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