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We present possibility analysis of using Y2O2S:Er,Yb for temperature sensing. Material samples were obtained by solution combustion method. We have used pulsed laser diode excitation at 980 nm. Our analysis is based on time resolved luminescence spectra acquired by a streak camera. Intensity ratios of prominent luminescence peaks were used for determining the temperature sensing curves. We compare the synthesized Y2O2S:Er,Yb material with other thermophosphors, showing its usefulness for temperature measurements up to 620 K. [ABSTRACT FROM AUTHOR]

In this work, we analyze optical characteristics of greater celandine (Chelidonium majus L.) ethanol solution extracts and fresh leaf samples. Optical emission of samples was measured using a pulsed laser excitation of tunable wavelengths (320–470 nm) and time-resolved detection system. Results of our analysis reveal two distinct alkaloid optical emission bands with different excitation characteristics. Chlorophyll fluorescence emission band was also detected. Time-resolved analysis of luminescent spectra shows that lifetimes of both alkaloid fluorescence bands and chlorophyll band are in nanosecond domain [ABSTRACT FROM AUTHOR]

In this study we analyze nano powder Gd2O3 doped with Er3+ and Yb3+. Material was synthesized by simple and efficient solution combustion method. The nano phosphor was optically excited at 980 nm by using pulsed laser diode. We have obtained time resolved upconversion luminescence spectra of nano powder samples of Gd2O3:Er,Yb using a streak camera and analyzed temperature dependence of erbium optical line emission intensities. The possibilities of using Gd2O3:Er,Yb for temperature sensing were analyzed by means of luminescence intensity ratio method. We show that synthesized Gd2O3:Er,Yb material is useful for temperature measurements up to 550 K. [ABSTRACT FROM AUTHOR]

We report results of measurements and calculations of absolute cross sections for electron scattering from furan molecules (C4H4O). The experimental absolute differential cross sections (DCSs) for elastic electron scattering were obtained for the incident energies from 50 eV to 300 eV and for scattering angles from 20º to 110º, by using a crossed electron-target beam setup and the relative flow technique for calibration to the absolute scale. The calculations of the electron interaction cross sections are based on a corrected form of the independent-atom method, known as the screening corrected additivity rule (SCAR) procedure and using an improved quasifree absorption model. The latter calculations also account for rotational excitations in the approximation of a free electric dipole and were used to obtain elastic DCSs as well as total and integral elastic cross sections which are tabulated in the energy range from 10 to 10 000 eV. All SCAR calculated cross sections agree very well with both the present and previously published experimental results. Additionally, calculations based on the first Born approximation were performed to calculate both elastic and vibrationally inelastic DCSs for all the modes of furane, in the energy range from 50 eV to 300 eV. The ratios of the summed vibrational to elastic DCSs are presented and discussed. Finally, the present results for furan are compared with previously published elastic DCSs for the tetrahydrofuran molecule and discussed. [ABSTRACT FROM AUTHOR]

The electronic spectroscopy of isolated tetrahydrofuran (THF) in the gas phase has been investigated using high-resolution photoabsorption spectroscopy in the 5.8–10.6 eV with absolute cross-section measurements derived. In addition, an electron energy loss spectrum was recorded at 100 eV and 10° over the 5–11.4 eV range. The He(I) photoelectron spectrum was also collected to quantify ionisation energies in the 9–16.1 eV spectral region. These experiments are supported by the first high-level ab initio calculations performed on the excited states of the neutral molecule and on the ground state of the positive ion. The excellent agreement between the theoretical results and the measurements allows us to solve several discrepancies concerning the electronic state spectroscopy of THF. The present work reconsiders the question of the lowest energy conformers of the molecule and its population distribution at room temperature. [ABSTRACT FROM AUTHOR]

Laser induced fluorescence is a powerful spectroscopic technique commonly used to study the structure and internal state distributions in molecules of biological interest. Betanin (C24H26N2O13) is a specific violet betacyanin and the most prominent pigment in the red beet root where it contributes to 75-95% of the total visible color. Our method of excitation of the beet root extract is based on the tunable (320 nm to 475 nm) Nd:YAG laser system. Fluorescence images of beet root extract excited at 320, 340, 360 and 400 nm were obtained. The fluorescence is observed in range from 580 nm to 660 nm. The influence of the solution concentrations on the fluorescence intensity is also analyzed. [ABSTRACT FROM AUTHOR]

In this paper we study the possibility of using the synthesized nanopowder samples of Gd2Zr2O7:Eu3+ for temperature measurements by analyzing the temperature effects on its photoluminescence. The nanopowder was prepared by solution combustion synthesis method. The photoluminescence spectra used for analysis of Gd2Zr2O7:Eu3+ nano phosphor optical emission temperature dependence were acquired using continuous laser diode excitation at 405 nm. The temperature dependencies of line emission intensities of transitions from 5D0 and 5D1 energy levels to the ground state were analyzed. Based on this analysis we use the two lines intensity ratio method for temperature sensing. Our results show that the synthesized material can be efficiently used as thermographic phosphor up to 650 K. [ABSTRACT FROM AUTHOR]

We report spectroscopic study of the laser induced indium plasma produced in air by using a Q-switched pulsed Nd:YAG laser at 1064 nm. A streak camera coupled to a spectrograph is used to record optical plasma emission. Plasma parameters (excitation temperature and electron density) characterizing the laser induced plasma are determined using the time-resolved analysis of the emission spectra. Indium plays an important role in electronic devices and LCD displays. However, indium is one of the rare elements. There are strong needs for recovery and recycling of rare materials from the used products and waste in the world. We present time-resolved laser induced breakdown spectra of atomic (In I) and ionic (In II) indium lines and other elements contained in the LCD displays, recorded using the fast streak camera, in different time ranges (from 500 ns to 20 μs). The study of indium lines showed in this paper could be useful for detecting indium and other elements in electronic waste for the purpose of recycling. Our LIBS measurements are applicable for any multielemental analysis in environmental physics, food quality control and ecology. [ABSTRACT FROM AUTHOR]

In this paper a method based on the Fourier transform and Padé approximants is investigated for analysis of holographic photonic crystal structures fabricated in Laboratory for Photonics, Institute of Physics, Belgrade. Padé approximants are numerical tool that can be used to accelerate the convergence of a slowly converging sequence. [ABSTRACT FROM AUTHOR]