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Sample records for thermostimulated luminescence tsl

  1. Thermostimulated luminescence in KBr-In crystals after optical creation of electronic excitation

    International Nuclear Information System (INIS)

    Popov, A.I.

    1990-01-01

    Thermal stability of the radiation defects produced in KBr-In by optical creation of the electronic excitation (optical creation of the excitons or optical ionization of In + -ions under C-band illumination) is investigated by the method of thermostimulated luminescence (TSL). A method of detection of prehistory defects, when the optical ionization of In + -ions and TSL are performed, is proposed. Quadratic dependence of V 2 -center creation upon dose is shown. This dependence confirms assocative mechanism of the creation of V 2 -centers from two interstitial centers

  2. Thermo-stimulated luminescence of ion-irradiated yttria-stabilized zirconia

    Energy Technology Data Exchange (ETDEWEB)

    Costantini, Jean-Marc [CEA, DMN, SRMA, 91191 Gif-sur Yvette Cedex (France); Beuneu, Francois [LSI, CEA-CNRS-Ecole Polytechnique, 91128 Palaiseau Cedex (France); Fasoli, Mauro; Galli, Anna; Vedda, Anna; Martini, Marco, E-mail: jean-marc.costantini@cea.fr [CNR-IFN (Italy)

    2011-03-23

    Yttria-stabilized zirconia (ZrO{sub 2}:Y{sup 3+}) single crystals (with 9.5 mol% Y{sub 2}O{sub 3}) were irradiated with ions (from 1 MeV He to 2.6 GeV U). Electron paramagnetic resonance (EPR) data show that two kinds of colour centres (F{sup +}-type and T centres) are produced. Thermo-stimulated luminescence (TSL) data exhibit a quite strong peak at {approx} 500-550 K in the glow curves of all irradiated samples regardless of the ion species and energy. Moreover, the 3D-TSL measurements reveal that this peak is correlated with a light emission at a wavelength of {approx} 620 nm (i.e. photon energy {approx} 2 eV). The TSL peak maximum temperatures are consistent with characteristic temperatures of about 500 K of annealing stages of colour centres. However, the trap-depth energies (ranging between 0.7 and 1.4 eV) deduced from the initial rise of partially cleaned TSL peaks, or from a rough approximation using Urbach's formula, are rather larger than the activation energies for defect recovery, ranging between 0.3 and 0.7 eV, as deduced from the EPR data. The processes involved in TSL are discussed in relation to available photoluminescence and defect energy-level data.

  3. Thermostimulated luminescence in KBr-In crystals after optical creation of electronic excitation. Termostimulirovannaya lyuminestsentsiya v kristallakh KBr-In pri opticheskom sozdanii ehlektronnykh vozbuzhdenij

    Energy Technology Data Exchange (ETDEWEB)

    Popov, A I [AN Latvijskoj SSR, Riga (USSR). Inst. Fiziki

    1990-01-01

    Thermal stability of the radiation defects produced in KBr-In by optical creation of the electronic excitation (optical creation of the excitons or optical ionization of In{sup +}-ions under C-band illumination) is investigated by the method of thermostimulated luminescence (TSL). A method of detection of prehistory defects, when the optical ionization of In{sup +}-ions and TSL are performed, is proposed. Quadratic dependence of V{sub 2}-center creation upon dose is shown. This dependence confirms assocative mechanism of the creation of V{sub 2}-centers from two interstitial centers.

  4. High-temperature peaks of thermostimulated luminescence in the ammonium halogens

    International Nuclear Information System (INIS)

    Kim, L.M.; Musenova, Eh.K.; Mukhamedrakhimov, K.U.

    2003-01-01

    The ammonium halogen crystals (AHC) are the close analogs of the alkali halogen crystals by the type of chemical bonds and crystal lattice structure. The ammonium halogen after irradiation by X-rays within 80-300 K range have two peaks of thermo-stimulation luminescence. Its maximums in dependence of anions type are in the 110-120 K and 170-180 K ranges. The first range is related with activation of auto-localized holes migration, and the second one - with the NH 3 + defects decay. Experimentally is established, that the pure ammonium halogens have memory about the previous irradiation at heating up to 300 K. After repeat irradiation the recombination luminescence high-temperature peak's shoulder is appearing. The second luminescence peak's shoulder revealing does not depend on the impurity center nature. It is known, that in the AHC there is the next thermo-stimulation luminescence peak within 340-360 K. The thermal annealing of this peak leads to the memory effect disappearance. So, the observing phenomenon is related with own defect of the matrix in the cation sublattice. Experimentally is established, that at a room temperature the AHC memorizing about previous irradiation during 20 h

  5. Recombination luminescence of Cu and/or Ag doped lithium tetraborate single crystals

    Energy Technology Data Exchange (ETDEWEB)

    Romet, I. [Institute of Physics, University of Tartu, W. Ostwaldi Str. 1, 50411 Tartu (Estonia); Aleksanyan, E. [Institute of Physics, University of Tartu, W. Ostwaldi Str. 1, 50411 Tartu (Estonia); A. Alikhanyan National Science Laboratory, 2 Br. Alikhanyan Str., 0036 Yerevan (Armenia); Brik, M.G. [Institute of Physics, University of Tartu, W. Ostwaldi Str. 1, 50411 Tartu (Estonia); College of Sciences, Chongqing University of Posts and Telecommunications, 400065 Chongqing (China); Institute of Physics, Jan Dlugosz University, Armii Krajowej 13/15, PL-42200 Czestochowa (Poland); Corradi, G. [Institute for Solid State Physics and Optics, Wigner Research Centre for Physics, Hungarian Academy of Sciences, Konkoly-Thege M. út 29-33, H-1121 Budapest (Hungary); Kotlov, A. [Photon Science at DESY, Notkestrasse 85, 22607 Hamburg (Germany); Nagirnyi, V., E-mail: vitali.nagirnoi@ut.ee [Institute of Physics, University of Tartu, W. Ostwaldi Str. 1, 50411 Tartu (Estonia); Polgár, K. [Institute for Solid State Physics and Optics, Wigner Research Centre for Physics, Hungarian Academy of Sciences, Konkoly-Thege M. út 29-33, H-1121 Budapest (Hungary)

    2016-09-15

    Complex investigations of thermostimulated luminescence (TSL) and radioluminescence properties of Li{sub 2}B{sub 4}O{sub 7} (LTB), LTB:Cu, LTB:Ag and LTB:Cu, Ag crystals suitable for tissue equivalent dosimeters were carried out in the temperature range 4.2–700 K. TSL, cathodoluminescence and X-ray excited luminescence spectra are compared to those measured under photoexcitation. The emission band at 4.6 eV in LTB:Ag is reliably related to Ag{sup +} ions based on the comparison of the results of optical spectroscopy studies and first principle calculations. Energy transfer from the relaxed exited state of the Ag{sup +} ion to the Cu{sup +} ion in double-doped LTB:Cu, Ag crystals is demonstrated. Thermostimulated recombination of charge carriers in irradiated crystals is seen to take place mainly at oxygen sites at low temperatures and at impurity sites at high temperatures. For the first time, the appearance of the low-temperature TSL peak at 90 K is assigned to ionic processes in LTB crystals. The appearance of pyroelectric flashes due to the lattice relaxation in the temperature region 90–240 K is demonstrated and their surface-related nature clarified. In accordance with EPR studies the dosimetric TSL peaks in copper and silver doped LTB crystals are attributed to thermally released electrons recombining with Cu{sup 2+} and Ag{sup 2+} centres.

  6. Construction of TSL lector equipment with spectral resolution for the determination of thermally stimulated luminescence (TSL) properties of NaCl: Tl+ induced by UV-visible radiation

    International Nuclear Information System (INIS)

    Alvarez Romero, J.T.

    1993-01-01

    A revision of physical models of thermally stimulated luminescence (TSL) in crystals induced by both ionizing and non-ionizing radiation is presented. Particular emphasis is given to the connection of TSL with other thermally stimulated processes and physico-chemical phenomena because basic information on physical mechanics for TSL can be obtained through them. Glow curves of TSL induced by UV-visible radiation in NaCl: Tl + were measured. Additionally, the following spectrums were obtained for the same samples: optical absorption, excitation, fluorescent emission, and TSL emission. An optical absorption peak was correlated with the Thallium ion concentration. With respect to the TSL emission spectrums, some peaks associated to Thallium dimmers were at 298 and at 480 nm; others which were attributed to NaCl intrinsic properties were at 365, 430, 450 and 525 nm. Also TSL glow curves were studied as a function of the Thallium ion concentration (0.8 ppm to 14.8 ppm). They were de convoluted so as to calculate the activation energy, the frequency factor and the kinetic order for each separate TSL peak. Anomalous values were observed for some frequency factors. A method and TSL lector equipment to obtain TSL emission spectra were developed. (Author)

  7. Cr-related centers in Gd3Ga5O12 polycrystals

    International Nuclear Information System (INIS)

    Kostyk, L.; Luchechko, A.; Zakharko, Ya.; Tsvetkova, O.; Kuklinski, B.

    2009-01-01

    The luminescence excitation spectra, emission spectra under photo- and X-ray excitation, luminescence decay kinetics and thermostimulated luminescence (TSL) of Gd 3 Ga 5 O 12 garnet (GGG) polycrystalline samples have been investigated. It was established that the spectrum of Cr 3+ ion emission were present in all TSL peaks. The activation energies of traps that are responsible for appearance of TSL in the region 295-600 K were estimated. It is shown that delocalization of electrons from the Cr 3+ e traps leads to the appearance of thermoluminescence (TL) glow peak at 390 K. The nature of other TSL peaks is discussed. The influence of visible light on the TSL intensity of the preliminary X-ray-irradiated samples is shown

  8. Photostimulated luminescence from a fluorobromozirconate glass-ceramic and the effect of crystallite size and phase

    CERN Document Server

    Secu, M; Spaeth, J M; Edgar, A; Williams, G V M; Rieser, U

    2003-01-01

    We report a systematic study of the photoluminescence (PL), photostimulated luminescence (PSL) and thermostimulated luminescence (TSL) from europium-and bromine-doped fluorozirconate glass-ceramics. Eu sup 2 sup + ions in the as-prepared glass show no PL, but after suitable thermal annealing hexagonal phase and orthorhombic phase barium bromide crystallites are precipitated and PL is observed from Eu sup 2 sup + ions in these crystallites. Room temperature PSL is observed from the orthorhombic phase, with an efficiency which is up to 9% of the well known crystalline storage phosphor BaFBr:Eu sup 2 sup +. The emission is at 404 nm, and there is a maximum in the stimulation at 580 nm. We associate the PSL with an optically quenchable peak in the glow curve, which has an activation energy of 1.20 eV and attribute this feature to a perturbed F centre. Room temperature PSL from glass-ceramics containing predominantly the hexagonal phase of BaBr sub 2 has a relative efficiency of less than 0.07%. The resultant trap...

  9. Thermo-stimulated current and dielectric loss in composite materials

    International Nuclear Information System (INIS)

    Nishijima, S.; Hagihara, T.; Okada, T.

    1986-01-01

    Thermo-stimulated current and dielectric loss measurements have been performed on five kinds of commercially available composite materials in order to study the electric properties of composite materials at low temperatures. Thermo-stimulated current measurements have been made on the composite materials in which the matrix quality was changed intentionally. The changes in the matrices were introduced by gamma irradiation or different curing conditions. Thermo-stimulated current and dielectric loss measurements revealed the number and the molecular weight of dipolar molecules. The different features of thermo-stimulated current and dielectric losses were determined for different composite materials. The gamma irradiation and the curing conditions especially affect the thermo-stimulated current features. The changes in macroscopic mechanical properties reflect those of thermo-stimulated current. It was found that the change in quality and/or degradation of the composite materials could be detected by means of thermo-stimulated current and/or dielectric loss measurements

  10. Thermally and photostimulated charge transfer on impurities and intrinsic defects in YAlO3

    International Nuclear Information System (INIS)

    Akkerman, V.A.; Bulka, G.P.; Vanshtejn, D.I.

    1989-01-01

    Methods of ESR and thermostimulated luminescence (TSL) were used to study thermo- and photostimulated change of valent state of impurity ions of iron, chromium and oxygen centers in YAlO 3 (YA). On the basis of recovery of ESR O 2 - intensity after pulsed irradiation it was established, that autolocalized holes (ALH) were mobile above 150 K with 0.54 eV activation energy. It is proposed that decay of autolocalized excitons (ALE) in YA is conditioned by thermal mobility of the hole component of ALE. Relationship of TSL with ESL data and results of high-temperature annealing of crystals in vacuum and in the air is discussed

  11. Preparation of lithium fluoride for thermoluminescent detectors of ionizing radiation

    Energy Technology Data Exchange (ETDEWEB)

    Mironenko, S.N.; Nepomnyashchikh, A.I.; Ikrami, D.D.; Paramzin, A.S.; Rakhimov, M.Eh.

    1985-03-01

    The thermostimulated luminescence (TSL) of lithium fluoride monocrystals depending on the method of preparation of starting raw material and features of its preliminary processing is investigated. It is shown that only lithium fluoride of high purity prepared through the stage of formation of hydrofluoride and its subsequent decomposition can be used without any additional processing for manufacturing monocrystal detectors of thermoluminescent dosimetry of the ionizing radiation with low intensity of low temperature peaks.

  12. UV induced photoluminescence and thermally stimulated luminescence of ThO2:Tb3+ phosphor

    International Nuclear Information System (INIS)

    Godbole, S.V.; Nagpal, J.S.; Page, A.G.

    2000-01-01

    Thorium oxide doped with trivalent terbium ions offers itself as a novel phosphor with its photo- and thermally-stimulated luminescence (PL and TSL) characteristics showing a marked change on sustained exposure to 254 and 365 nm ultraviolet (UV) radiation. The reduction in luminescence intensity of Tb 3+ ions, on irradiation with 254 nm photons and subsequent restoration on exposure to 365 nm, has been correlated with the complimentary behaviour in UV-induced TSL. These changes are, in turn, ascribed to inter-configurational (f-d) transitions and e-h formation and recombination processes. UV radiation induced TSL output increases linearly with incident UV radiant energy at a constant radiation flux; however, for a fixed exposure, TSL output increases with increase in radiant flux

  13. Thermally stimulated luminescence and persistent luminescence of β-irradiated YAG:Pr"3"+ nanophosphors produced by combustion synthesis

    International Nuclear Information System (INIS)

    Santacruz-Gomez, K.; Meléndrez, R.; Gil-Tolano, M.I.; Jimenez, J.A.; Makale, M.T.; Barboza-Flores, M.; Castaneda, B.; Soto-Puebla, D.; Pedroza-Montero, M.; McKittrick, J.; Hirata, G.A.

    2016-01-01

    In this work, the thermally stimulated luminescence (TSL) and persistent luminescence (PLUM) properties of praseodymium doped yttrium aluminum garnet (YAG:Pr"3"+) exposed to β-irradiation are reported. X-ray diffraction (XRD) confirms a single phase of YAG obtained by the combustion method. Transmission electron microscopy (TEM) shows that powder particles appear to be irregular crystals with an average size of 67 nm. TSL glow-curve deconvolution of YAG:Pr"3"+ after β-irradiation consist in six peaks centered at 394, 450, 467, 543, 637 and 705 K. The TSL fading and PLUM signals were found to be associated with at least with two different kinds of traps, corresponding to the peaks located at 394, 450 and 467 K. YAG:Pr"3"+ nanophosphors analyzed in this work showed interesting features about the dosimetric sensitivity as well as the reproducibility for both TSL/PLUM techniques, with good linearity dose response. These results indicate that nanocrystalline YAG:Pr3"+ is a good candidate for dosimetric applications in the range of 80 mGy-20 Gy. - Highlights: • β-irradiated YAG:Pr"3"+ TSL consist in 394, 450, 467, 543, 637 and 705 K peaks. • YAG:Pr"3"+ is a good candidate for dosimetry in the range of 80 mGy-20 Gy. • PLUM can be potentially used for in vivo, in situ and quasi in real time dosimetry.

  14. UV induced photoluminescence and thermally stimulated luminescence of ThO{sub 2}:Tb{sup 3+} phosphor

    Energy Technology Data Exchange (ETDEWEB)

    Godbole, S.V.; Nagpal, J.S.; Page, A.G. E-mail: agpage@magnum.barc.ernet.in

    2000-08-15

    Thorium oxide doped with trivalent terbium ions offers itself as a novel phosphor with its photo- and thermally-stimulated luminescence (PL and TSL) characteristics showing a marked change on sustained exposure to 254 and 365 nm ultraviolet (UV) radiation. The reduction in luminescence intensity of Tb{sup 3+} ions, on irradiation with 254 nm photons and subsequent restoration on exposure to 365 nm, has been correlated with the complimentary behaviour in UV-induced TSL. These changes are, in turn, ascribed to inter-configurational (f-d) transitions and e-h formation and recombination processes. UV radiation induced TSL output increases linearly with incident UV radiant energy at a constant radiation flux; however, for a fixed exposure, TSL output increases with increase in radiant flux.

  15. Luminescence and photosensitivity of PbI2 crystals

    International Nuclear Information System (INIS)

    Novosad, S.S.; Novosad, I.S.; Matviishin, I.M.

    2002-01-01

    One studied effect of temperature treatment and storage conditions on spectra features of PbI 2 crystals grown by the Bridgman-Stockbarger method from salt additionally purified by directed crystallization. Spectra of X-ray luminescence, photoluminescence and thermostimulated luminescence were investigated within 85-295 K temperature range under stationary X-ray excitation and emission of N 2 -laser. One studied photoelectret properties of those crystals under 85 K. Luminescence of PbI 2 crystals with maximum within 595 nm region observed following their thermal annealing under 475-495 K temperature and typical for near-the-surface section of specimens may be caused by oxygen-containing centres [ru

  16. The recombination channels of luminescence excitation in YAG:Yb single crystalline films

    International Nuclear Information System (INIS)

    Zakharko, Ya.M.; Luchechko, A.P.; Ubizskii, S.B.; Syvorotka, I.I.; Martynyuk, N.V.; Syvorotka, I.M.

    2007-01-01

    Absorption and emission spectra, luminescence decay kinetics and thermostimulated luminescence of X-ray irradiated YAG:Yb single crystalline films were studied. Two emission bands peaked at 420 and 488 nm have been detected in the investigated films. The strong thermal quenching of luminescence band at 488 nm was observed above 160 K. The influence of growth conditions and annealing in air on the lifetime of Yb 3+ ion excited state in the IR spectral region have been revealed. The recombination mechanisms of the f-f transition at Yb 3+ ion excitation, as well as the mechanism of lifetime shortening for the excited Yb 3+ luminescence have been discussed

  17. Thermally and optically stimulated luminescence of early medieval blue-green glass mosaics

    Energy Technology Data Exchange (ETDEWEB)

    Galli, A. E-mail: anna.galli@mater.unimib.it; Martini, M.; Montanari, C.; Sibilia, E

    2004-12-01

    The preliminary results of a study related to luminescent mechanisms in glass mosaic tesserae are presented. The samples came from a medieval glass deposit found during archaeological excavations in the S. Lorenzo Church in Milan. Energy Dispersive X-rays Fluorescence (EDXRF) measurements were performed to obtain information on the elemental composition of the materials. Thermally Stimulated Luminescence (TSL, both conventional and wavelength resolved) and Optically Stimulated Luminescence (OSL) analyses allowed to get information about traps and luminescence centres. The observed luminescence characteristics were close to that of quartz, showing the presence of an easy to bleach trap (300 deg. C, 1.95 eV) and of a hard to bleach trap (350 deg. C, 2.20 eV); charge transfer phenomena, involving the low-temperature peaks have been observed. There is a strong indication that the easy to bleach traps are responsible for both OSL and TSL emission at 300 deg. C.

  18. Thermally and optically stimulated luminescence of early medieval blue-green glass mosaics

    International Nuclear Information System (INIS)

    Galli, A.; Martini, M.; Montanari, C.; Sibilia, E.

    2004-01-01

    The preliminary results of a study related to luminescent mechanisms in glass mosaic tesserae are presented. The samples came from a medieval glass deposit found during archaeological excavations in the S. Lorenzo Church in Milan. Energy Dispersive X-rays Fluorescence (EDXRF) measurements were performed to obtain information on the elemental composition of the materials. Thermally Stimulated Luminescence (TSL, both conventional and wavelength resolved) and Optically Stimulated Luminescence (OSL) analyses allowed to get information about traps and luminescence centres. The observed luminescence characteristics were close to that of quartz, showing the presence of an easy to bleach trap (300 deg. C, 1.95 eV) and of a hard to bleach trap (350 deg. C, 2.20 eV); charge transfer phenomena, involving the low-temperature peaks have been observed. There is a strong indication that the easy to bleach traps are responsible for both OSL and TSL emission at 300 deg. C

  19. Study of TSL and OSL properties of dental ceramics for accidental dosimetry applications

    International Nuclear Information System (INIS)

    Veronese, Ivan; Galli, Anna; Cantone, Marie Claire; Martini, Marco; Vernizzi, Fabrizio; Guzzi, Gianpaolo

    2010-01-01

    Interest is increasing in the development of new methodologies for accidental dose assessment, exploiting the luminescence and dosimetric properties of objects and materials which can be usually found directly on exposed subjects and/or in the contaminated area. In this work, several types of ceramics employed for dental prosthetics restoration, including both innovative materials used as sub-frames for the construction of the inner part of dental crowns (core), and conventional porcelains used for the fabrication of the external layer (veneer), were investigated with regard to their thermally and optically stimulated luminescence (TSL and OSL respectively) properties, in view of their potential application in accidental dosimetry. The sensitivity to ionizing radiation proved to strongly depend on the type and brand of ceramic, with minimum detectable dose ranging from few mGy up to several tens of mGy. A linear dose-response was observed for most of the samples. However, the luminescence signals were characterised by a significant fading, which has to be taken into account for a reliable accidental dose assessment after a radiation exposure event.

  20. Applicability and performance of an imaging plate at subzero temperatures

    International Nuclear Information System (INIS)

    Sakoda, Akihiro; Ishimori, Yuu; Hanamoto, Katsumi; Kawabe, Atsushi; Kataoka, Takahiro; Nagamatsu, Tomohiro; Yamaoka, Kiyonori

    2010-01-01

    The performance of imaging plates (IPs) has not been studied at temperatures lower than 0 o C. In the present study, an IP was irradiated with gamma rays emitted from the mineral monazite at temperatures between -80 and 30 o C to determine its fundamental properties. The IP response as a function of irradiation time was found to be linear, suggesting that the IP works properly at low temperatures. Fading, an effect which should be considered at temperatures of more than 0 o C, was not observed at -30 and -80 o C. Furthermore, the fading-corrected PSL value of the IP irradiated at -80 o C was lower than at other temperatures (30, 5 and -30 o C). This can be explained by thermostimulated luminescence (TSL). Since the only intensive TSL peak in the temperature range from -80 to 30 o C is present at about -43 o C, some of the electrons trapped at F centers recombine with holes through the process of TSL before the stored radiation image is read out at room temperature. This finding suggests that the apparent sensitivity of the IP is lower at -80 o C although it is similar to sensitivities between -30 and 30 o C. This low sensitivity should be corrected to perform quantitative measurements.

  1. Spectrally resolved thermally stimulated luminescence of irradiated anion-defective alumina single crystals

    Energy Technology Data Exchange (ETDEWEB)

    Kortov, V., E-mail: vskortov@mail.ru [Ural Federal University, Mira Str. 19, 620002 Ekaterinburg (Russian Federation); Lushchik, A.; Nagirnyi, V. [Institute of Physics, University of Tartu, W. Ostwald Str. 1, 50411 Tartu (Estonia); Ananchenko, D. [Ural Federal University, Mira Str. 19, 620002 Ekaterinburg (Russian Federation); Romet, I. [Institute of Physics, University of Tartu, W. Ostwald Str. 1, 50411 Tartu (Estonia)

    2017-06-15

    Thermally stimulated luminescence (TSL) spectra in the 313–580 K temperature range have been studied in anion-defective alumina crystals (named in literature as Al{sub 2}O{sub 3}:C) exposed to different irradiation doses. The TSL curve features two peaks with the maxima at T{sub m1}=437 K and T{sub m2}=565 K. The TSL spectrum of the first peak contains the emission of F centers and the R line of Cr{sup 3+} impurity ions. The absence of the emission of F{sup +} centers indicates that electron traps are responsible for the first dosimetric TSL peak. The TSL spectrum of the second peak features emission bands of F, F{sup +} centers, R line as well as a wide band centered at 550 nm and associated with the formation of aggregate centers (F{sub 2} and F{sub 2}{sup 2+}) under irradiation. Possible excitation mechanisms of the TSL emission bands that involve both electron and hole traps related to anion vacancies and impurities are discussed. - Highlights: •TSL curve of alumina crystals features peaks at 437 and 565 K. •There are emission bands of 410 and 695 nm in the TSL spectrum of the first peak. •TSL spectrum of the second peak features bands of F, F{sub 2}-type centers and the R line of trivalent chromium. •Excitation mechanisms of the emission bands in TSL spectra are discussed.

  2. Thermally stimulated luminescence and electron paramagnetic resonance studies on uranium doped calcium phosphate

    CERN Document Server

    Natarajan, V; Veeraraghavan, R; Sastry, M D

    2003-01-01

    Thermally stimulated luminescence (TSL) and electron paramagnetic resonance (EPR) studies on uranium doped calcium phosphate yielded mechanistic information on the observed glow peaks at 365, 410 and 450 K. TSL spectral studies of the glow peaks showed that UO sub 2 sup 2 sup + acts as the luminescent center. Electron paramagnetic resonance studies on gamma-irradiated samples revealed that the predominant radiation induced centers are H sup 0 , PO sub 4 sup 2 sup - , PO sub 3 sup 2 sup - and O sup - ion. Studies on the temperature dependence studies of the EPR spectra of samples annealed to different temperatures indicate the role of H sup 0 and PO sub 4 sup 2 sup - ions in the main glow peak at 410 K.

  3. SrAl2O4:Eu2+ (1%) luminescence under UV, VUV and electron beam excitation

    Science.gov (United States)

    Nazarov, M.; Mammadova, S.; Spassky, D.; Vielhauer, S.; Abdullayeva, S.; Huseynov, A.; Jabbarov, R.

    2018-01-01

    This paper reports the luminescence properties of nanosized SrAl2O4:Eu2+ (1%) phosphors. The samples were prepared by combustion method at 600 °C, followed by annealing of the resultant combustion ash at 1000 °C in a reductive (Ar + H2) atmosphere. X-ray diffraction (XRD), photo luminescence (PL) and cathodoluminescence (CL) analysis and thermal stimulated luminescence (TSL) method were applied to characterize the phosphor. For the first time a peak at 375 nm was observed in CL spectra of SrAl2O4:Eu2+ (1%) nanophosphors. Luminescence excitation spectra analysis have shown that this peak is related to crystal defects. Also in TSL curve one strong peak was observed in the region above room temperature (T = 325 K), which is attributed to lattice defects, namely oxygen vacancies. A green LED was fabricated by the combination of the SrAl2O4:Eu2+ (1%) nanosized phosphor and a 365 nm UV InGaN chip.

  4. DEMATEL METHOD IN ERP SYSTEMS FOR TSL BRANCH

    Directory of Open Access Journals (Sweden)

    Witold TORBACKI

    2017-12-01

    Full Text Available The article introduces issues concerning the implementation of key performance indicators (KPIs dedicated to the TSL (Transport-Shipping-Logistics branch. The KPIs are used in different modules of the ERP (Enterprise resource planning information systems, which support strategic decision making. Selected indicators have been used to create four perspectives of Balanced Scorecard in accordance with Balanced Scorecard methodology. Using the multi-factor method of DEMATEL (Decision Making Trial and Evaluation Laboratory analysis, the evaluation of indicators and Balanced Scorecard’s perspectives has been performed. This article can be useful to persons interested in the implementation of modern solutions in ERP applications dedicated to the TSL branch. Presented article can be useful to persons from upper management of TSL companies who are interested in modern methods of supporting strategic management and for IT system developers who are considering expanding modules of ERP software solutions dedicated to TSL industry which support strategic management and decision making.

  5. Positron and TSL-studies of superconducting ceramics YBa 2Cu3Oy for various y

    International Nuclear Information System (INIS)

    Aravin, L.G.; Bobolev, A.V.; Gustov, V.V.; Ryzhkov, A.I.; Shantarovich, V.P.; Vydrin, S.N.; Zainullin, R.N.

    1990-01-01

    The effect of oxygen content on the defectivity and structure of the high temperature superconductor YBa 2 Cu 3 O y (6.0 < y < 7.0) has been investigated using positron annihilation lifetime spectroscopy (LS) and thermally stimulated luminescence (TSL). Data analysis and comparison enabled a conclusion on positron trapping by metal (Ba,Cu) but not by oxygen vacancies (contrary to electrons). The trapping rate was sufficiently dependent on oxygen content in the sample. The transition range y between orthorombic (superconducting) and tetragonal (nonsuperconducting) phases was characterized by the increased content of not only oxygen but also metal (Ba,Cu) vacancies

  6. Intrinsic luminescence of un-doped borate glasses

    International Nuclear Information System (INIS)

    Kindrat, I.I.; Padlyak, B.V.; Drzewiecki, A.

    2017-01-01

    The nature of intrinsic luminescence in the un-doped borate glasses of different compositions has been investigated using spectroscopic methods including photoluminescence, optical absorption, electron paramagnetic resonance (EPR), and thermally stimulated luminescence (TSL). The un-doped borate glasses with Li 2 B 4 O 7 , LiKB 4 O 7 , CaB 4 O 7 , and LiCaBO 3 basic compositions were obtained from corresponding polycrystalline compounds in the air with usage the standard technology of glasses. Three different broad emission bands in the UV–Visible spectral range have been observed under different wavelength of photoexcitation. The luminescence kinetics of the observed emission bands have been registered and analysed. The nature and possible mechanisms of the intrinsic luminescence in the investigated borate glasses are considered and discussed based on the obtained results and referenced data.

  7. CSR in TSL companies

    Directory of Open Access Journals (Sweden)

    Joanna DYCZKOWSKA

    2015-03-01

    Full Text Available TSL companies are characterized by high dynamics of an increase of incomes, and hence increased shipping. Owing to a rational policy in the area of the consolidation of production and distribution, they may boast of a better use of the means of transport. The purpose of this article is to present the activities in the area of the eco-friendly CSR aspect in the activities of TSL companies taking into consideration particularly logistic operators. The research methods used in the study include an analysis of secondary data, observations and comparative analyses. Road transport in the shipping structure comes first and it constitutes 84% of freights. In the year 2009, in Poland greenhouse gas emissions from road transport amounted to 42.5 million tons (4.84% of the EU member states and CO emissions were 41.9 million tons (analogically, 4.83% of environment pollutions in the European Union. This causes an emission of fumes into the atmosphere. The policy of sustainable development pursued by logistic operators under corporate social responsibility is a response to the abovementioned data. They take decisions concerning social and environmental aspects. The activities of TSL companies under CSR need to provide an answer to customer expectations and needs, and they have to cause an increase of competitiveness on the market. The selected four largest logistic operators conduct the following eco-friendly activities on the highest level: fume emission reports and the control of these emissions, transport of hazardous goods (ADR, voluntary services in the scope of environmental protection and cooperation with eco-friendly organizations. There are those activities which call for improvement: a limitation of the emission of fumes, waste management and sewage treatment policy.

  8. Influence of photochemical transformations upon optic-spectral characteristics of iodine cadmium crystals with copper dopant

    International Nuclear Information System (INIS)

    Novosad, S.S.

    2000-01-01

    The influence of photochemical transformations upon absorption. X-ray, photo- and thermostimulated luminescence of crystals CdI 2 :CuI, CdI 2 :CuI and CdI 2 :CuO grown by Stockbarger - Czochralski method has been studied. The photochemical reactions in crystals of iodine cadmium with the dopant of copper leads to reducing the intensity of X-ray, photo- and thermostimulated luminescence, the appearance of new luminescent centers is not observed

  9. A comparative study of the models dealing with localized and semi-localized transitions in thermally stimulated luminescence

    International Nuclear Information System (INIS)

    Kumar, Munish; Kher, R K; Bhatt, B C; Sunta, C M

    2007-01-01

    Different models dealing with localized and semi-localized transitions, namely Chen-Halperin, Mandowski and the model based on the Braunlich-Scharmann (BS) approach are compared. It has been found that for recombination dominant situations (r > 1, the three models differ. This implies that for localized transitions under recombination dominant situations, the Chen-Halperin model is the best representative of the thermally stimulated luminescence (TSL) process. It has also been found that for the TSL glow curves arising from delocalized recombination in Mandowski's semi-localized transitions model, the double peak structure of the TSL glow curve is a function of the radiation dose as well as of the heating rate. Further, the double peak structure of the TSL glow curves arising from delocalized recombination disappears at low doses as well as at higher heating rates. It has also been found that the TSL glow curves arising from delocalized recombination in the semi-localized transitions model based on the BS approach do not exhibit double peak structure as observed in the Mandowski semi-localized transitions model

  10. Alginate Microspheres Containing Temperature Sensitive Liposomes (TSL for MR-Guided Embolization and Triggered Release of Doxorubicin.

    Directory of Open Access Journals (Sweden)

    Merel van Elk

    Full Text Available The objective of this study was to develop and characterize alginate microspheres suitable for embolization with on-demand triggered doxorubicin (DOX release and whereby the microspheres as well as the drug releasing process can be visualized in vivo using MRI.For this purpose, barium crosslinked alginate microspheres were loaded with temperature sensitive liposomes (TSL/TSL-Ba-ms, which release their payload upon mild hyperthermia. These TSL contained DOX and [Gd(HPDO3A(H2O], a T1 MRI contrast agent, for real time visualization of the release. Empty alginate microspheres crosslinked with holmium ions (T2* MRI contrast agent, Ho-ms were mixed with TSL-Ba-ms to allow microsphere visualization. TSL-Ba-ms and Ho-ms were prepared with a homemade spray device and sized by sieving. Encapsulation of TSL in barium crosslinked microspheres changed the triggered release properties only slightly: 95% of the loaded DOX was released from free TSL vs. 86% release for TSL-Ba-ms within 30 seconds in 50% FBS at 42°C. TSL-Ba-ms (76 ± 41 μm and Ho-ms (64 ± 29 μm had a comparable size, which most likely will result in a similar in vivo tissue distribution after an i.v. co-injection and therefore Ho-ms can be used as tracer for the TSL-Ba-ms. MR imaging of a TSL-Ba-ms and Ho-ms mixture (ratio 95:5 before and after hyperthermia allowed in vitro and in vivo visualization of microsphere deposition (T2*-weighted images as well as temperature-triggered release (T1-weighted images. The [Gd(HPDO3A(H2O] release and clusters of microspheres containing holmium ions were visualized in a VX2 tumor model in a rabbit using MRI.In conclusion, these TSL-Ba-ms and Ho-ms are promising systems for real-time, MR-guided embolization and triggered release of drugs in vivo.

  11. The nature of unusual luminescence in natural calcite, CaCO3

    Energy Technology Data Exchange (ETDEWEB)

    Gaft, M.; Nagli, L.; Panczer, G.; Waychunas, G.; Porat, N.

    2008-11-01

    The unusual luminescence of particular varieties of natural pink calcite (CaCO{sub 3}) samples was studied by laser-induced time-resolved luminescence spectroscopy at different temperatures. The luminescence is characterized by intense blue emission under short-wave UV lamp excitation with an extremely long decay time, accompanied by pink-orange luminescence under long wave UV excitation. Our investigation included optical absorption, natural thermostimulated luminescence (NTL) and Laser-Induced Breakdown Spectroscopy (LIBS) studies. Two luminescence centers were detected: a narrow violet band, with {lambda}{sub max} = 412 nm, {Delta} = 45 nm, two decay components of {tau}{sub 1} = 5 ns and {tau}{sub 2} = 7.2 ms, accompanied by very long afterglow, and an orange emission band with {lambda}{sub max} = 595 nm, {Delta} = 90 nm and {tau} = 5 ns. Both luminescence centers are thermally unstable with the blue emission disappearing after heating at 500 C, and the orange emission disappearing after heating at different temperatures starting from 230 C, although sometimes it is stable up to 500 C in different samples. Both centers have spectral-kinetic properties very unusual for mineral luminescence, which in combination with extremely low impurity concentrations, prevent their identification with specific impurity related emission. The most likely explanation of these observations may be the presence of radiation-induced luminescence centers. The long violet afterglow is evidently connected with trapped charge carrier liberation, with their subsequent migration through the valence band and ultimate recombination with a radiation-induced center responsible for the unusual violet luminescence.

  12. Characterization of damage created by alpha disintegrations in radionuclear waste glass

    International Nuclear Information System (INIS)

    Jacquet-Francillon, N.; Mueller, P.

    1990-01-01

    Study of thermostimulated luminescence of an alpha irradiated glass used as radionuclear waste glass has revealed the formation of a structural defect induced by alpha irradiation. To detect this structural modification the thermostimulated signal of an alpha irradiated sample is recorded under certain conditions. The nature of generated defects has been established using synthetic glasses of more simple composition such as silica or boro-silicate glasses. Results obtained with these simple glasses are transposed to alpha irradiated radionuclear waste glass. The problem is to see how autoirradiated glass could evolve in time. For this purpose actinide-doped glasses are now being fabricated and specific thermostimulated luminescence equipment has been developed for this purpose

  13. Closure certification report: TA-35 TSL-125 surface impoundment

    International Nuclear Information System (INIS)

    1991-01-01

    This closure report documents closure activities for the TA-35 TSL-125 surface impoundment and associated structures at Los Alamos National Laboratory (the Laboratory). Prior to formal approval of the closure plan, the decision was made to proceed with closure activities to prevent any further releases from the site following informal discussions with New Mexico Environment Department (NMED) personnel. The closure plan is a revision of the previously submitted draft dated July 1988. Clean closure of the TSL-125 site was accomplished through: Removal and proper disposal of all wastes contained within the surface impoundment system; Decontamination and/or removal and proper disposal of the surface impoundment, its associated structures, and contaminated soil underlying the impoundment area; Sampling and analysis of soil to determine the presence and concentrations of any hazardous constituents remaining in the soil at the TSL-125 site; and Demonstration through a risk assessment that any constituents remaining in the soil at the TSL-125 site pose no threat to human health and the environment. All remaining soil concentrations of hazardous constituents were below health-based action levels. Analytical results indicated that benzidine, n-nitrosodimethylamine, and n-nitrosodi-n-propylamine were not detected at or above their limits of quantitation and beryllium was not present at or above its laboratory detection limit. However, the limits of quantitation and detection for these constituents were greater than their calculated health-based action levels. To demonstrate that these constituents were not present, historical data was researched and it was determined that the constituents were not utilized at the Building 125 site. 4 refs., 8 figs., 1 tab

  14. Evaluation of trapping parameters of thermally stimulated luminescence glow curves in Cu-doped Li2B4O7 phosphor

    International Nuclear Information System (INIS)

    Manam, J.; Sharma, S.K.

    2005-01-01

    Evaluation of trapping parameters, including order of kinetics, activation energy and frequency factor, is one of the most important aspect of studies in the field of thermally stimulated luminescence (TSL). A polycrystalline sample of Cu-doped Li 2 B 4 O 7 was prepared by the melting method. Formation of the doped compound was checked by use of Fourier-transform infrared (FTIR) spectroscopy. TSL studies of the Cu-doped lithium tetraborate sample shows three glow peaks, the maximum emission occurring, respectively, at a temperature of 175 deg. C, 290 deg. C and 350 deg. C, the intensity of the 175 deg. C-glow peak being the maximum. The trapping parameters associated with this prominent glow peak of Cu-doped lithium tetraborate are reported herein, using the isothermal luminescence decay and glow curve shape (Chen's) methods. Our results show very good agreement between the trapping parameters calculated by the two methods

  15. Selective creation of colour centres and peaks of thermally stimulated luminescence by VUV photons in LiF single crystals

    International Nuclear Information System (INIS)

    Vasil'chenko, E.; Kudryavtseva, I.; Lushchik, A.; Lushchik, Ch.; Nagirnyi, V.

    2005-01-01

    Processes of radiation creation and annealing of Frenkel defects as well as electron-hole processes have been studied in LiF single crystals with a various content of impurity ions by means of highly sensitive method of thermally stimulated luminescence (TSL) and other optical methods. In highly pure LiF crystals, X-irradiated at 4.2 K, the TSL peaks connected with the annealing of interstitial fluorine ions (25-40 K) or atoms, i.e. H centres (50-65 K) and self-trapped holes (120-140 K) have been separated. For the first time, the creation spectra of the TSL peaks at 480 and 550 K by 10-33 eV-photon irradiation at 295 K have been measured. The anomalously high creation efficiency of the TSL peak at 480 K by 11.7-12.3 eV and 26-27 eV photons is interpreted as the creation of near-impurity electronic excitations both, directly by photons and by hot conduction electrons. (copyright 2005 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  16. Cavitation erosion tests of high tensile stainless steels for the Techno-Superliner (TSL-F) hulls; Techno superliner (TSL-F) sentai kozoyo kokyodo stainless ko no cavitation erosion

    Energy Technology Data Exchange (ETDEWEB)

    Matsuo, M.; Ito, H.; Shibasaki, K. [NKK Corp., Tokyo (Japan); Mizuta, A.; Sugimoto, H. [Kawasaki Heavy Industries, Ltd., Kobe (Japan); Tomono, Y. [Hitachi Zosen Corp., Osaka (Japan)

    1996-12-31

    Investigations were given by using the magnetostrictive vibration method and the high-speed fluid testing method on cavitation erosion resistance of high-tensile stainless steels thought to have high applicability to submerged hull structures of Techno-Supeliner (TSL-L). The investigations revealed that these steels have nearly equivalent resistance to even SUS 304 or 15-5PH steel which is thought to have the highest cavitation erosion resistance among the conventional materials used customarily. An experiment using both materials provided a result different quantitatively but similar qualitatively in relative merits between the materials. Correlation between both materials was presented. A cavitation erosion experiment using a 1/6 scale model of the actual TSL-F was carried out to measure the amount of cavitation erosion generated on wing surfaces. Results from the experiment were used to attempt estimation of cavitation erosion amount at the level of the actual TSL-F. 21 refs., 12 figs., 3 tabs.

  17. Cavitation erosion tests of high tensile stainless steels for the Techno-Superliner (TSL-F) hulls; Techno superliner (TSL-F) sentai kozoyo kokyodo stainless ko no cavitation erosion

    Energy Technology Data Exchange (ETDEWEB)

    Matsuo, M; Ito, H; Shibasaki, K [NKK Corp., Tokyo (Japan); Mizuta, A; Sugimoto, H [Kawasaki Heavy Industries, Ltd., Kobe (Japan); Tomono, Y [Hitachi Zosen Corp., Osaka (Japan)

    1997-12-31

    Investigations were given by using the magnetostrictive vibration method and the high-speed fluid testing method on cavitation erosion resistance of high-tensile stainless steels thought to have high applicability to submerged hull structures of Techno-Supeliner (TSL-L). The investigations revealed that these steels have nearly equivalent resistance to even SUS 304 or 15-5PH steel which is thought to have the highest cavitation erosion resistance among the conventional materials used customarily. An experiment using both materials provided a result different quantitatively but similar qualitatively in relative merits between the materials. Correlation between both materials was presented. A cavitation erosion experiment using a 1/6 scale model of the actual TSL-F was carried out to measure the amount of cavitation erosion generated on wing surfaces. Results from the experiment were used to attempt estimation of cavitation erosion amount at the level of the actual TSL-F. 21 refs., 12 figs., 3 tabs.

  18. UV-induced photoluminescence and thermally stimulated luminescence of CaSO{sub 4}:Eu and CaF{sub 2}:Tb{sup 3+} phosphors

    Energy Technology Data Exchange (ETDEWEB)

    Godbole, S.V.; Nagpal, J.S.; Page, A.G. E-mail: agpage@magnum.barc.ernet.in

    2000-08-15

    Ultraviolet radiation induced changes in photoluminescence (PL) and thermally stimulated luminescence (TSL) of europium activated calcium sulphate (CaSO{sub 4}:Eu{sup 3+}, Eu{sup 2+}) and terbium doped calcium fluoride (CaF{sub 2}:Tb{sup 3+}) phosphors have been studied. PL measurements suggest conversion of Eu{sup 3+} to Eu{sup 2+} on 254 nm irradiation corresponding to charge transfer band of Eu{sup 3+} ions and reduction of Eu{sup 2+} ions with 365 nm illumination representing a f-d transition of Eu{sup 2+} ions. Similar studies carried out on CaF{sub 2}:Tb{sup 3+} phosphor, however, do not show any significant wavelength specific changes. The integrated TSL output appears to be rate-dependent for both phosphors. The wavelength dependent changes in TSL output observed for CaSO{sub 4}:Eu phosphor have been correlated with those obtained in PL studies. The changes in TSL and PL characteristics of CaF{sub 2}:Tb{sup 3+} phosphor have been explained on the basis of stabilisation of traps based on matrix specific charge similarities.

  19. Luminescent and structural properties of Zn_xMg_1_-_xWO_4 mixed crystals

    International Nuclear Information System (INIS)

    Krutyak, N.; Nagirnyi, V.; Spassky, D.; Tupitsyna, I.; Dubovik, A.; Belsky, A.

    2016-01-01

    The structural and luminescent properties of perspective scintillating Zn_xMg_1_-_xWO_4 mixed crystals were studied. The following characteristics were found to depend linearly on x value: the energy of several vibrational modes detected by Raman spectroscopy, the bandgap width deduced from the shift of the excitation spectrum onset of a self-trapped exciton (STE) emission, the position of thermally stimulated luminescence peaks. It is also shown that the thermal stability of the STE luminescence decreases gradually when x decreases. These data indicate that each Zn_xMg_1_-_xWO_4 mixed crystal is not a mixture of two constituents, but possesses its original crystalline structure, as well as optical and luminescent properties. - Highlights: • The structural and luminescent properties of Zn_xMg_1_-_xWO_4 were studied. • The energy of Raman modes, the bandgap width, TSL peak position linearly depend on x. • Each Zn_xMg_1_-_xWO_4 possesses its original crystalline structure.

  20. Thermostimulated recombination processes in LiBaF.sub.3./sub. crystals

    Czech Academy of Sciences Publication Activity Database

    Kulis, P.; Tale, I.; Gromuls, I.; Nikl, Martin; Ichinose, N.; Shimamura, K.

    2004-01-01

    Roč. 38, - (2004), s. 723-726 ISSN 1350-4487 R&D Projects: GA AV ČR(CZ) KSK1010104 Keywords : LiBaF 3 * radiation defects * TSL * absorption Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 0.664, year: 2004

  1. A study of the thermostimulated evolution of labelled hydrogen sulfide from the leached basalt fibers

    International Nuclear Information System (INIS)

    Zheleznov, A.V.; Zyuzin, A.Yu.; Bekman, I.N.

    1991-01-01

    Thermostimulated separation of labelled hydrogen sulfide from basalt fibers leached by hydrochloric acid is investigated by the method of radioactive tracers. It is shown that the type of H 2 35 S thermosorption spectrum depends on the presence of water traces in a fibrous adsrobent. Formal order and activation energy of thermodesorption of labelled hydrogen sulfide as well as inhomogeneity of porous structure of adsorbents based on basalt fibers are established

  2. SO4--SO3- radical pair formation in Ce doped and Ce, U co-doped K3Na(SO4)2: EPR evidence and its role in TSL

    International Nuclear Information System (INIS)

    Natarajan, V.; Seshagiri, T.K.; Kadam, R.M.; Sastry, M.D.

    2002-01-01

    Thermally stimulated luminescence (TSL) and electron paramagnetic resonance (EPR) studies were carried out on cerium doped and cerium-uranium co-doped K 3 Na(SO 4 ) 2 samples after γ-irradiation. Three glow peaks around 352, 415 and 475 K were observed and their spectral characteristics have shown that Ce 3+ and UO 2 2+ act as the emission centres in K 3 Na(SO 4 ) 2 :Ce and K 3 Na(SO 4 ) 2 :Ce, U, respectively. In Ce-U co-doped sample, energy transfer from cerium to uranium takes place. The commonly occurring radiation-induced centres in sulphates, viz SO 3 - and SO 4 - were observed by EPR and SO 4 - radical ion was found to take part in the TSL emission at 415 K. The hitherto unknown information, however, is the formation of SO 4 - -SO 3 - radical pair creating deep traps in these lattices, apparently assisted by the dopants. This is the first observation of such radical pair formation leading to the identification of deep traps in this lattice. The radical pair, (SO 3 - -SO 4 - ) which is stable up to 970 K, decreases the intensity of the peak at 415 K due to the depletion of SO 4 - centres

  3. Direct determination of graphene quantum dots based on terbium-sensitized luminescence

    Science.gov (United States)

    Llorent-Martínez, Eulogio J.; Molina-García, Lucía; Durán, Gema M.; Ruiz-Medina, Antonio; Ríos, Ángel

    2018-06-01

    Graphene quantum dots (GQD) were determined in water samples using terbium-sensitized luminescence (TSL). Terbium ions complex with GQD due to the carboxylic groups that are usually present in these nanomaterials, increasing the luminescence signal of terbium. In Tb(III)-GQD complexes, GQD absorb energy at their characteristic excitation wavelength and transfer it to terbium ion, which emits at its particular emission wavelength. The analytical signal, measured at λexc = 257 nm and λem = 545 nm, increases proportionally to GQD concentration between 50 and 500 μg L-1. Under optimum conditions, the proposed method presents a detection limit of 15 μg L-1 and is selective to GQD in the presence of other nanomaterials of similar size. As GQD are highly water-soluble, they are potential contaminants in environmental or drinking waters water samples, and hence the method was applied to the analysis of different drinking waters which were the target samples for the application of the developed method.

  4. Low temperature luminescence and charge carrier trapping in a cryogenic scintillator Li{sub 2}MoO{sub 4}

    Energy Technology Data Exchange (ETDEWEB)

    Spassky, D.A., E-mail: deris2002@mail.ru [Institute of Physics, University of Tartu, Ravila 14c, 50411 Tartu (Estonia); Skobeltsyn Institute of Nuclear Physics, Moscow State University, 119991 Moscow (Russian Federation); Nagirnyi, V. [Institute of Physics, University of Tartu, Ravila 14c, 50411 Tartu (Estonia); Savon, A.E. [Skobeltsyn Institute of Nuclear Physics, Moscow State University, 119991 Moscow (Russian Federation); Kamenskikh, I.A. [Physics Faculty, Moscow State University, 119991 Moscow (Russian Federation); Barinova, O.P.; Kirsanova, S.V. [D. Mendeleyev University of Chemical Technology of Russia, 125047 Moscow (Russian Federation); Grigorieva, V.D.; Ivannikova, N.V.; Shlegel, V.N. [Nikolaev Institute of Inorganic Chemistry, SB RAS, 630090 Novosibirsk (Russian Federation); Aleksanyan, E. [Institute of Physics, University of Tartu, Ravila 14c, 50411 Tartu (Estonia); A.Alikhanyan National Science Laboratory, 2 Br. Alikhanyan Str., 0036 Yerevan (Armenia); Yelisseyev, A.P. [Sobolev Institute of Geology and Mineralogy, SB RAS, 630090 Novosibirsk (Russian Federation); Belsky, A. [Institute of Light and Matter, CNRS, University Lyon1, 69622 Villeurbanne (France)

    2015-10-15

    The luminescence and optical properties of promising cryogenic scintillator Li{sub 2}MoO{sub 4} were studied in the temperature region of 2–300 K. The data on luminescence spectra and decay characteristics, excitation spectra, thermostimulated luminescence curves and spectra as well as transmission and reflectivity spectra are presented for the single crystals grown by two different procedures, the conventional Czochralski method and the low-temperature gradient Czochralski technique. The bandgap of Li{sub 2}MoO{sub 4} is estimated from the analysis of transmission, luminescence excitation and reflectivity spectra. Up to three luminescence bands with the maxima at 1.98, 2.08 and 2.25 eV are detected in the emission spectra of crystals and their origin is discussed. In the thermoluminescence curves of both studied crystals, two high-intensity peaks were observed at 22 and 42 K, which are ascribed to the thermal release of self-trapped charge carriers. The coexistence of self-trapped electrons and holes allows one to explain the poor scintillation light yield of Li{sub 2}MoO{sub 4} at low temperatures. - Highlights: • Single crystals of Li{sub 2}MoO{sub 4} were grown by two methods. • The transparency cutoff (~4.3 eV) and bandgap values (<4.9 eV) are estimated. • The emission 2.08 eV is ascribed to self-trapped excitons and quenches at T>7 K. • Shallow traps considerably influence the energy transfer to emission centres. • Co-existence of self-trapped holes and electrons results in a low light yield.

  5. Bandgap engineering of the Lu{sub x}Y{sub 1−x}PO{sub 4} mixed crystals

    Energy Technology Data Exchange (ETDEWEB)

    Levushkina, V.S., E-mail: viktoriia.levushkina@ut.ee [Institute of Physics, University of Tartu, Ravila 14c, 50411 Tartu (Estonia); Physics Faculty, Moscow State University, Leninskiye Gory 1-2, 11991 Moscow (Russian Federation); Spassky, D.A. [Institute of Physics, University of Tartu, Ravila 14c, 50411 Tartu (Estonia); Skobeltsyn Institute of Nuclear Physics, Moscow State University, Leninskiye Gory 1-2, 11991 Moscow (Russian Federation); Aleksanyan, E.M. [Institute of Physics, University of Tartu, Ravila 14c, 50411 Tartu (Estonia); A. Alikhanyan National Science Laboratory, Yerevan Physics Institute, Alikhanyan Yeghbayrneri St. 2, 0036 Yerevan (Armenia); Brik, M.G. [Institute of Physics, University of Tartu, Ravila 14c, 50411 Tartu (Estonia); College of Sciences, Chongqing University of Posts and Telecommunications, 400065 Chongqing (China); Institute of Physics, Jan Dlugosz University, Armii Krajowej 13/15, PL-42200 Czestochowa (Poland); Institute of Physics, Polish Academy of Sciences, Al. Lotników 32/46, 02-668 Warsaw (Poland); Tretyakova, M.S.; Zadneprovski, B.I. [Central Research and Development Institute of Chemistry and Mechanics, Nagatinskaya St. 16a, 115487 Moscow (Russian Federation); Belsky, A.N. [Institute of Light and Matter, CNRS, University Lyon1, 69622 Villeurbanne (France)

    2016-03-15

    Bandgap modification of the Lu{sub x}Y{sub 1−x}PO{sub 4} mixed crystals has been studied by thermostimulated luminescence (TSL) and ab-initio calculation methods. Doping of Lu{sub x}Y{sub 1−x}PO{sub 4} with Ce{sup 3+} allowed to follow up the changes of electron traps depth, caused by the modification of the bottom of conduction band. The observed gradual shift of the most intensive TSL peaks to higher temperatures with increase of x value was connected with the high-energy shift of the conduction band bottom. According to the band structure calculations the bottom of the conduction band is formed by the 5d and 4d states of Lu and Y, respectively. Therefore, substitution of one cation by another is responsible for the observed variation of the electronic and optical properties. Doping with Eu{sup 3+} was used to study the modification of the hole traps and the top of the valence band in Lu{sub x}Y{sub 1−x}PO{sub 4}. The independence of the TSL peaks position on x value in Lu{sub x}Y{sub 1−x}PO{sub 4}:Eu{sup 3+} allows to conclude that the top of the valence band is negligibly affected by the cation substitution. According to the band structure calculations the top of the valence band is formed by the O 2p electronic states, which are not affected by the cation substitution. The resulting increase of the bandgap with x value is confirmed by the data of ab-initio calculations. - Highlights: • Band structure modification with x in Lu{sub x}Y{sub 1−x}PO{sub 4}:RE{sup 3+} (RE=Ce, Eu) is studied. • Depth of electron traps is affected by the bandgap modification. • Increase of bandgap with x is due to the shift of conduction band bottom.

  6. Thermally stimulated luminescence studies in combustion ...

    Indian Academy of Sciences (India)

    Wintec

    irradiated aluminum oxide samples were studied. A broad PL ... formance, especially when doped with carbon. A good amount of work on TSL of ... to the spectrograph through optical fibre for detection and analysis. The TSL measurements ...

  7. TSL Family Therapy Followed by Improved Marital Quality and Reduced Oxidative Stress

    Science.gov (United States)

    Kim, Jae Yop; Kim, Dong Goo; Nam, Seok In

    2012-01-01

    Objectives: The current study evaluated the effectiveness of a form of family therapy developed in Korea. The "Thank you--Sorry--Love" (TSL) model was applied to a group of elderly retired men to improve the quality of their marriage and to reduce their stress. Methods: Thirty married retired Korean men were assigned to three groups.…

  8. Thermally and optically stimulated radiative processes in Eu and Y co-doped LiCaAlF6 crystal

    International Nuclear Information System (INIS)

    Fukuda, Kentaro; Yanagida, Takayuki; Fujimoto, Yutaka

    2015-01-01

    Yttrium co-doping was attempted to enhance dosimeter performance of Eu doped LiCaAlF 6 crystal. Eu doped and Eu, Y co-doped LiCaAlF 6 were prepared by the micro-pulling-down technique, and their dosimeter characteristics such as optically stimulated luminescence (OSL) and thermally stimulated luminescence (TSL) were investigated. By yttrium co-doping, emission intensities of OSL and TSL were enhanced by some orders of magnitude. In contrast, scintillation characteristics of yttrium co-doped crystal such as intensity of prompt luminescence induced by X-ray and light yield under neutron irradiation were degraded

  9. Thermally and optically stimulated radiative processes in Eu and Y co-doped LiCaAlF{sub 6} crystal

    Energy Technology Data Exchange (ETDEWEB)

    Fukuda, Kentaro, E-mail: ken-fukuda@tokuyama.co.jp [Tokuyama Corporation, 1-1 Mikage-cho, Shunan-shi, Yamaguchi 745-8648 (Japan); Yanagida, Takayuki; Fujimoto, Yutaka [Kyushu Institute of Technology, 2-4 Hibikino, Wakamatsu, Kitakyushu, Fukuoka 808-0196 (Japan)

    2015-06-01

    Yttrium co-doping was attempted to enhance dosimeter performance of Eu doped LiCaAlF{sub 6} crystal. Eu doped and Eu, Y co-doped LiCaAlF{sub 6} were prepared by the micro-pulling-down technique, and their dosimeter characteristics such as optically stimulated luminescence (OSL) and thermally stimulated luminescence (TSL) were investigated. By yttrium co-doping, emission intensities of OSL and TSL were enhanced by some orders of magnitude. In contrast, scintillation characteristics of yttrium co-doped crystal such as intensity of prompt luminescence induced by X-ray and light yield under neutron irradiation were degraded.

  10. Thermostimulated transitions of radiation colour centers in fiber light guides on the base of pure quartz glass

    International Nuclear Information System (INIS)

    Abramov, A.V.; Dianov, E.M.; Karpechev, V.N.; Kornienko, L.S.; Rybaltovskij, A.O.; Chernov, P.V.

    1987-01-01

    Study on properties and characteristics of induced absorption (IA) in glass fiber light guides (GFLG) with a pure quartz glass core is continued. Effect of thermal-stimulated construction of colour radiation centers (CRC) giving induced absorption bands at 670, 550, and 380 nm has been detected. Effective temperatures of these IA band annealings have been determined as well as bands at 340 nm and induced absorption IR edge. Positions of IA band halfwidths and maxima on the assumption that IA bands have the Gauss form. It is assumed that CRC photo- and thermostimulated construction may occur with participation of physically dissolved in a glass grid gases or their radiolysis products

  11. The composite nature of the thermoluminescence UV emission of quartz

    Energy Technology Data Exchange (ETDEWEB)

    Fasoli, Mauro, E-mail: mauro.fasoli@mater.unimib.it [Dipartimento di Scienza dei Materiali, Università degli Studi di Milano Bicocca, via R. Cozzi 55, I-20125 Milano (Italy); INFN, Sezione di Milano Bicocca, Piazza della Scienza 1, I-20126 Milano (Italy); Martini, Marco [Dipartimento di Scienza dei Materiali, Università degli Studi di Milano Bicocca, via R. Cozzi 55, I-20125 Milano (Italy); INFN, Sezione di Milano Bicocca, Piazza della Scienza 1, I-20126 Milano (Italy)

    2016-05-15

    The radioluminescence (RL) spectra of three types of quartz have been compared to those obtained from wavelength resolved thermally stimulated luminescence (TSL) measurements. A detailed numerical deconvolution into Gaussian components allowed to identify which of the bands are involved in either types of luminescence processes. The blue “A band” at 2.51 eV was confirmed to dominate both RL and TSL spectra in samples exposed to prolonged irradiation. The UV emission of the 110 °C TSL peak was found to be composite. Analogously to what previously reported for RL spectra, an annealing at 500 °C for 10 min induced a strong enhancement of the “C band” at 3.42 eV. This effect was particularly evident in natural and pre-irradiated quartz. A second intense UV component, the “M band” at 3.7 eV, was found to contribute to both TSL and RL spectra of samples annealed at 1000 °C for 10 min. A further broad UV emission seems to be involved only in RL emission but not in the TSL one.

  12. Study of the luminescence properties of dental materials for their use in accidental dosimetry

    International Nuclear Information System (INIS)

    Veronese, Ivan; Cantone, Marie C.; Guzzi, Gianpaolo

    2008-01-01

    Full text: The current social and political situation in many world areas and the increasing hostilities between countries and cultures have accentuated the risk of a malicious use of ionising radiations. Terrorist attacks with the intentional disseminations of radioactive materials in urban settlements may involve a large number of persons, and a rapid estimation of the severity of the exposure is required for undertaking suitable protective actions and supporting decision making. Promising methodologies for a prompt dose evaluation, are those exploiting the luminescence and dosimetric properties of objects and materials which can be easily found in the contaminated area. Among these objects, dental materials have the advantage to be on contact with human body and they could therefore represent individual dosimeters in case of accidental exposure to ionising radiation. The interest in the use of dental ceramics for dosimetric purposes dates back to late 1970, however, it is only through the use of high-sensitive experimental techniques and instrumentation today available, that the potentiality of such materials as accidental dosimeters can be exploited. Moreover, innovative materials are being continuously introduced into the market, containing new additives and pigments with peculiar optical properties. In this study, Thermally Stimulated Luminescence (TSL) and Optically Stimulated Luminescence (OSL) techniques are applied to investigate the luminescence and dosimetric properties of several dental materials, including resins, glass and feldspatic ceramics, and also zirconia and alumina based ceramics, being their use widely increased in the recent years in substitution of metal cores. (author)

  13. Electronic relaxations of radiative defects of the anion sublattice in cesium bromide crystals and exoemission of electrons

    CERN Document Server

    Galyij, P V

    2002-01-01

    The paper presents the results of investigations of thermostimulated exoelectron emission (TSEE) from CsBr crystal, excited by moderate doses (D <= 10 sup 4 Gy) of ultraviolet (h nu <= 7 eV) that selectively creates anion excitons and radiative defects in the anion sublattice. Having used the previously established connection between thermoactivated processes such as thermostimulated exoemission, electroconductivity, and luminescence in the irradiated crystal lattice, the concentrations of exoemission-active centers (EAC) and kinetics parameters of TSEE are calculated. The EAC concentration calculated on a base of the bulk, thermoactivated-recombinational, and band-gap Auger-like exoemission mechanisms, are in satisfactory agreement with the concentration of electron color centers in the irradiated crystals.

  14. Light emitting structures porous silicon-silicon substrate

    International Nuclear Information System (INIS)

    Monastyrskii, L.S.; Olenych, I.B.; Panasjuk, M.R.; Savchyn, V.P.

    1999-01-01

    The research of spectroscopic properties of porous silicon has been done. Complex of photoluminescence, electroluminescence, cathodoluminescence, thermostimulated depolarisation current analyte methods have been applied to study of geterostructures and free layers of porous silicon. Light emitting processes had tendency to decrease. The character of decay for all kinds of luminescence were different

  15. Preparation and determination of the luminescent characteristics of ZrO2 in powder

    International Nuclear Information System (INIS)

    Rivera M, T.; Olvera T, L.; Azorin N, J.; Soto E, A.M.; Velazquez O, C.; Campero C, A.

    2004-01-01

    In this work the luminescent characteristics of the ZrO 2 are presented using the method of Thermally Stimulated Luminescence (TSL), also called thermoluminescence (Tl). The powders of ZrO 2 were obtained by two preparation methods: for precipitation and for evaporation of Sol-gel. The luminescent characteristics of the ZrO 2 are determined using a lamp of radiation of UV light and a radiation source of beta particles of 90 Sr/ 90 Y. Using the method of thermal stimulation the curve representative thermoluminescent of the previously irradiated material was obtained. The curve Tl of the ZrO 2 irradiated with UV light presents a maximum in 180 C. Likewise, the spectrum of the curve Tl of the ZrO 2 irradiated with particles beta presents a maximum centered in 181 C. While using gamma radiation like excitement source one has a spectrum with a peak centered in 184 C. When subjecting the materials obtained by sol-gel to a process of calcination at 1000 C for 24 hours a curved Tl it presents with two maxim in 185 and in 290 C respectively. The intensity of the response induced in the material it is a decisive factor to continue studying the dosimetric characteristics of the ZrO 2 what allows to consider it as a potential material to use it in the beta particle dosimetry and of the UV light using the thermoluminescence method (Tl). (Author)

  16. Electron self-trapped at molybdenum complex in lead molybdate: An EPRand TSL comparative study

    Czech Academy of Sciences Publication Activity Database

    Buryi, Maksym; Laguta, Valentyn; Fasoli, M.; Moretti, F.; Trubitsyn, M.; Volnianskii, M.; Vedda, A.; Nikl, Martin

    2017-01-01

    Roč. 192, Dec (2017), s. 767-774 ISSN 0022-2313 R&D Projects: GA MŠk LO1409; GA MŠk LM2015088; GA ČR GA17-09933S EU Projects: European Commission(XE) 690599 - ASCIMAT Institutional support: RVO:68378271 Keywords : EPR * wavelength resolved TSL * self-trapped electron * lead molybdate * molecular orbitals Subject RIV: BM - Solid Matter Physics ; Magnetism OBOR OECD: Condensed matter physics (including formerly solid state physics, supercond.) Impact factor: 2.686, year: 2016

  17. Effect of thermal annealing on scintillation properties of Ce:Gd{sub 2}Y{sub 1}Ga{sub 2.7}Al{sub 2.3}O{sub 12} under different atmosphere

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Chao; Ding, Dongzhou; Wu, Yuntao; Li, Huanying; Chen, Xiaofeng; Shi, Jian; Wang, Qingqing; Ye, Le; Ren, Guohao [Chinese Academy of Sciences, Shanghai Institute of Ceramics, Shanghai (China)

    2017-05-15

    Cerium-doped 1% Ce:Gd{sub 2}Y{sub 1}Ga{sub 2.7}Al{sub 2.3}O{sub 12}(GYGAG) single crystal samples grown via Czochralski method were annealed under air, O{sub 2} and N{sub 2} atmospheres from 350 to 1400 C. The X-ray excited luminescence spectra, energy spectra and UV as well as thermally stimulated luminescence (TSL) spectra were performed comparatively on ''as-grown'' and thermally annealed samples. It was found that the luminescence efficiency after annealing in air and O{sub 2} was significantly enhanced compared to the non-annealed samples and this phenomenon was suggested to be caused by the existence of some oxygen vacancies in the Ce:GYGAG crystals. And the oxygen vacancies in the as-grown GYGAG crystals can be effectively eliminated by means of annealing in O{sub 2} containing atmosphere without changing the luminescence mechanism. From the TSL curves before and after annealing, three traps within 77-650 K were found to be related to oxygen vacancies. (orig.)

  18. Thermally stimulated exoelectron emission from solid Xe

    International Nuclear Information System (INIS)

    Khyzhniy, I.V.; Grigorashchenko, O.N.; Savchenko, E.V.; Ponomarev, A.N.; Bondybey, V.E.

    2007-01-01

    Thermally-stimulated emission of exoelectrons and photons from solid Xe pre-irradiated by low-energy electrons were studied. A high sensitivity of thermally-stimulated luminescence (TSL) and thermally-stimulated exoelectron emission (TSEE) to sample prehistory was demonstrated. It was shown that electron traps in unannealed samples are characterized by much broader distribution of trap levels in comparison with annealed samples and their concentration exceeds in number that in annealed samples. Both phenomena, TSL and TSEE, were found to be triggered by release of electrons from the same kind of traps. The data obtained suggest a competition between two relaxation channels: charge recombination and electron transport terminated by TSL and TSEE. It was found that TSEE predominates at low temperatures while at higher temperatures TSL prevails. An additional relaxation channel, a photon-stimulated exoelectron emission pre-irradiated solid Xe, was revealed

  19. Study of thermoluminescence emissions of dosimetric phosphors; the detection of intermediate neutrons

    International Nuclear Information System (INIS)

    Santos, E.N. dos.

    1979-01-01

    Thermally stimulated luminescence (TSL) studies have been carried out in cold-pressed CaSO 4 +DY 2 O 3 +KCl (specimen 1) and natural CaF 2 +DY 2 O 3 + KCl (specimen 2) polycrystaline samples. The ratios of the TSL sensivities of specimens 1 and 2 relative to that of 6 LiF:Mg;Ti (TLD-600) are found to be 24 and 3, respectively. The minimum detectable neutron fluence has been determined to be approximately 3.5X10 5 n/cm 2 . The determination of the effective half-life of the TSL emission lead to the identification of the isotope responsible for the self-irradiation of the specimens: 165 66 DY. (F.E.) [pt

  20. Når alderen indhenter én. Kropslighed, aldring og profession hos gymnasiets idrætslærere. Ph.d. afhandling

    DEFF Research Database (Denmark)

    Christensen, Mette Krogh

    Når alderen indhenter én – om kropslighed, aldring og profession hos gymnasiets idrætslærere er en ph.d.-afhandling udarbejdet af Mette Krogh Christensen på Institut for Idræt (Afdeling for Historie og Samfundsvidenskab), Københavns Universitet. Afhandlingen handler om, på hvilken måde alder spil...

  1. Influence of SrF_2-doping in AlN ceramics on scintillation and dosimeter properties

    International Nuclear Information System (INIS)

    Kojima, Kaori; Okada, Go; Fukuda, Kentaro; Yanagida, Takayuki

    2016-01-01

    In this study, we synthesized undoped AlN and SrF_2-doped AlN (AlN-SrF_2) ceramics by Spark Plasma Sintering (SPS), and we characterized their optical, scintillation and dosimeter properties. The prepared undoped AlN ceramic had gray color and visually non-transparent whereas, with an addition of SrF_2, the transparency improved and became translucent. The measured in-line transmittance was approximately 0.2% at wavelengths longer than 500 nm. While the addition of SrF_2 decreased the scintillation intensity, the decay time was significantly fastened, which is a great advantage for fast photon counting-based measurements. Both the thermally-stimulated luminescence (TSL) and optically-stimulated luminescence (OSL) showed good linear response from the milli-gray range to over 10 Gy. The sensitivity seems to decrease by an addition of SrF_2 as it suppresses structural defect centers which are responsible for dosimeter properties. However, the main TSL glow peak position shifts to higher temperature with the addition of SrF_2, which indicates that inclusion of SrF_2 improves the TSL signal stability. - Highlights: • We synthesized undoped and SrF_2-doped AlN ceramics by Spark Plasma Sintering. • We evaluated scintillator and dosimeter properties of undoped and SrF_2-doped AlN. • By doping with SrF_2, the decay time is shortened. • By doping with SrF_2, the stability of TSL and OSL is improved.

  2. Closure certification report: TA-35 TSL-125 surface impoundment

    International Nuclear Information System (INIS)

    1991-01-01

    This report summarizes the actions that were taken to clean close the TA-35 TSL-125 surface impoundment Building 125 is used for developing electron guns and related laser assemblies/equipment for a Laser Technology Research Program at the Laboratory. There is no permanent outfall from the surface impoundment; however, the impoundment accidentally overtopped on December 3, 1986, spilling an unknown volume of insulating oil and water into Ten Site Canyon. Sandbags were installed around the surface impoundment on June 25, 1988, to provide additional freeboard in the impoundment and reduce the risk of overtopping during a precipitation event. On July 1, 1988, the impoundment again overtopped releasing an unknown volume of insulating oil and water. Actions taken include removal of waste from the surface impoundment and its associated structures, decontamination of the floor trough and piping inside Building 125, grouting of the piping connecting the floor drain/trough system to the impoundment, decontamination, removal, and disposal of the impoundment liner and sandbags lining the top of the impoundment, and removal and disposal of contaminated soil underlying the impoundment area. Procedures followed to verify that clean closure objectives have been met are also documented in this report. Initial verification was performed through an extensive soil sampling and analysis program

  3. Sterile medfly males of the tsl Vienna 8 genetic sexing strain display improved mating performance with ginger root oil

    International Nuclear Information System (INIS)

    Paranhos, Beatriz Jordao; Alves, Renata Morelli; McInnis, Donald; Damasceno, Itala; Malavasi, Aldo; Goncalves, Nilmara; Costa, Maria de Lourdes; Walder, Julio; Nascimento, Antonio

    2006-01-01

    A key point of the sterile insect technique applied to the medfly, Ceratitis capitata, is that the sterile males produced in the laboratory should have at least a minimal sexual compatibility with wild females. Among several genetic sexing tsl (Temperature Sensitive Lethal) strains of C. capitata mass-reared around the world, the Biofabrica Moscamed Brasil has chosen the most recent mass produced tsl strain, Vienna 8 (V8), which has been evaluated in the San Francisco River Valley, Brazil, since April, 2005. The tests were accomplished in field cages, with different treatments for V8 males, sterile or fertile, exposed to the aroma of ginger root oil (GRO) or not, versus wild males and females. Males of one strain (V8 or wild) were painted white on the thorax the day before the mating tests. All the insects were virgin, and early in the morning (7-8 A.M.) males were released inside the field cages, 10 min. before females. Mating pairs were collected in glass vials, until early afternoon. From this raw data, both the type of male mating and the time in copula were recorded for each pair. Then, the total percentage of mated females, the RSI (Relative Sterility Index), and Fried's competitiveness values (C), were calculated for each field cage. The percentage of females mated was statistically higher to sterile males exposed to GRO than to non exposed to GRO. Time in copula was significantly higher for wild flies than for laboratory flies, except for the case of fertile V8 males exposed to GRO x wild females. The RSI and C values were significantly higher for V8 males (irradiated and fertile) treated with GRO than for V8 males not treated with GRO. The results indicate that there is adequate sexual compatibility between sterile males of the tsl Vienna 8 strain and wild C. capitata females from the San Francisco River Valley, Brazil. Also, the radiation dose of 95 Gy, used to sterilize the males, did not affect their sexual activity. Ginger root oil acted as a

  4. Sterile medfly males of the tsl Vienna 8 genetic sexing strain display improved mating performance with ginger root oil

    Energy Technology Data Exchange (ETDEWEB)

    Paranhos, Beatriz Jordao; Alves, Renata Morelli, E-mail: bjordao@cpatsa.embrapa.b [EMBRAPA Semi-Arido, Petrolina, PE (Brazil); McInnis, Donald [U.S. Department of Agriculture (USDA/ARS/PBARC), Honolulu, HI (United States). Agricultural Research Service. Pacific Basin Agricultural Research Center; Uramoto, Keiko [Universidade de Sao Paulo (USP), SP (Brazil); Damasceno, Itala; Malavasi, Aldo [Biofabrica Moscamed Brasil, Juazeiro, BA (Brazil); Goncalves, Nilmara [Valexport, Petrolina, PE (Brazil); Costa, Maria de Lourdes; Walder, Julio [Centro de Energia Nuclear na Agricultura (CENA/USP), Piracicaba, SP (Brazil); Nascimento, Antonio [EMBRAPA Mandioca e Fruticultura, Cruz das Almas, BA (Brazil)

    2006-07-01

    A key point of the sterile insect technique applied to the medfly, Ceratitis capitata, is that the sterile males produced in the laboratory should have at least a minimal sexual compatibility with wild females. Among several genetic sexing tsl (Temperature Sensitive Lethal) strains of C. capitata mass-reared around the world, the Biofabrica Moscamed Brasil has chosen the most recent mass produced tsl strain, Vienna 8 (V8), which has been evaluated in the San Francisco River Valley, Brazil, since April, 2005. The tests were accomplished in field cages, with different treatments for V8 males, sterile or fertile, exposed to the aroma of ginger root oil (GRO) or not, versus wild males and females. Males of one strain (V8 or wild) were painted white on the thorax the day before the mating tests. All the insects were virgin, and early in the morning (7-8 A.M.) males were released inside the field cages, 10 min. before females. Mating pairs were collected in glass vials, until early afternoon. From this raw data, both the type of male mating and the time in copula were recorded for each pair. Then, the total percentage of mated females, the RSI (Relative Sterility Index), and Fried's competitiveness values (C), were calculated for each field cage. The percentage of females mated was statistically higher to sterile males exposed to GRO than to non exposed to GRO. Time in copula was significantly higher for wild flies than for laboratory flies, except for the case of fertile V8 males exposed to GRO x wild females. The RSI and C values were significantly higher for V8 males (irradiated and fertile) treated with GRO than for V8 males not treated with GRO. The results indicate that there is adequate sexual compatibility between sterile males of the tsl Vienna 8 strain and wild C. capitata females from the San Francisco River Valley, Brazil. Also, the radiation dose of 95 Gy, used to sterilize the males, did not affect their sexual activity. Ginger root oil acted as a

  5. Complex reactions of excitable tissue on radio-, photo- and thermostimulation

    International Nuclear Information System (INIS)

    Neu, E.; Bischof, R.; Seidenbusch, W.; Willich, N.

    2003-01-01

    Photo-, radio and thermotherapies are an essential part of modern treatment. A summary of some selected earlier and resent data about motor reactions of non- and vascular preparations is given [1-4, incl. methods]. Radiostimulation: X-irradiation (50-150 kV: 1-50 Gy, 10-30 Gy/min) induced in frog and rat aorta (helical strips) as well as guinea pig (GP) (and rat) detrusor, t. coli, frog lung and neuro-muscle prep. of hirudo med. reversible contractions. Photostimulation: After UV-irradiation (450 W Xenon lamp) frog aorta and hirudo (max. 267-308 nm) and frog lung (max. 294-335 nm) also reacted with reversible contr., but rat aorta and GP t. coli (max. 294-335 nm) with a photorelaxation. Laser (He-Ne 632.8 nm, 10 mW) induced photocontractions in detrusor and hirudo. Thermostimulation: After hypothermia (37 to 25/5 deg C) a relaxation of frog and rat aorta appeared: X-ray contr. of frog aorta and GP detrusor was potentiated, but of rat aorta - abolished; hyperthermic (37 to 42/45 deg C) tonic contr. of rat rct. were observed. Differences in the radio-, photo- and thermosensitizing / -inhibitory effects by drugs and ions are observed. The influence of non-ionizing radiation (infrared laser 9.5-11.5 μm and 50 μm-1 mm) as well as of micro- (cm) and ultrashort (m) waves (MHz, GHz) on excitable tissue in context of combined effects with ionizing radiation and signal transduction will be studied. Lit.: Furchgott et al [a] J Gen Physiol 44, 499, 1961; [b] Nature 218, 682, 1968. [2] Michailov et al, Strahlenther [a] 167, 5, 311-318, 1991 and 165, 860-5, 1989 and 159, 448-451, 1983; [b] Proc. ICRR Dublin, 234, 1999 and Wuerzburg 400, 1995. [3] Neu et al [a] in: IORT, Vg 'Blaue Eule' 27-39, 1993; [b] Gyn Rdsch 33/S1, 206-7, 1993. [4] Welscher et al [a] Front Rad Ther Oncol 31, Karger 22-35, 1997; [b] Proc ICRR Wuerzburg 434, 1995 and Toronto 265, 1991; [c] Physiol Res 48, S138, 1999; [d] Eur J. Physiol 430/S, 604, 1995?

  6. Luminescence nanothermometry

    Science.gov (United States)

    Jaque, Daniel; Vetrone, Fiorenzo

    2012-07-01

    The current status of luminescence nanothermometry is reviewed in detail. Based on the main parameters of luminescence including intensity, bandwidth, bandshape, polarization, spectral shift and lifetime, we initially describe and compare the different classes of luminescence nanothermometry. Subsequently, the various luminescent materials used in each case are discussed and the mechanisms at the root of the luminescence thermal sensitivity are described. The most important results obtained in each case are summarized and the advantages and disadvantages of these approaches are discussed.The current status of luminescence nanothermometry is reviewed in detail. Based on the main parameters of luminescence including intensity, bandwidth, bandshape, polarization, spectral shift and lifetime, we initially describe and compare the different classes of luminescence nanothermometry. Subsequently, the various luminescent materials used in each case are discussed and the mechanisms at the root of the luminescence thermal sensitivity are described. The most important results obtained in each case are summarized and the advantages and disadvantages of these approaches are discussed. This work was supported by the Universidad Autónoma de Madrid and Comunidad Autónoma de Madrid (Project S2009/MAT-1756), by the Spanish Ministerio de Educacion y Ciencia (MAT2010-16161) and by Caja Madrid Foundation.

  7. Luminescence and photothermally stimulated defects creation processes in PbWO4:La3+, Y3+ (PWO II) crystals

    International Nuclear Information System (INIS)

    Auffray, E.; Korjik, M.; Zazubovich, S.

    2015-01-01

    Photoluminescence and thermally stimulated luminescence (TSL) are studied for a PbWO 4 crystal grown by the Czochralski method at Bogoroditsk Technical Chemical Plant, Russia from the melt with a precise tuning of the stoichiometry and co-doped with La 3+ and Y 3+ ions (the PWO II crystal). Photothermally stimulated processes of electron and hole centers creation under selective UV irradiation of this crystal in the 3.5–5.0 eV energy range and the 85–205 K temperature range are clarified and the optically created electron and hole centers are identified. The electrons in PWO II are mainly trapped at the (WO 4 ) 2− groups located close to single La 3+ and Y 3+ ions, producing the electron {(WO 4 ) 3− –La 3+ } and {(WO 4 ) 3− –Y 3+ } centers. The holes are mainly trapped at the regular oxygen ions O 2− located close to La 3+ and Y 3+ ions associated with lead vacancies, producing the hole O − (I)-type centers. No evidence of single-vacancy-related centers has been observed in PWO II. The data obtained indicate that excellent scintillation characteristics of the PWO II crystal can be explained by a negligible concentration of single (non-compensated) oxygen and lead vacancies as the traps for electrons and holes, respectively. - Highlights: • Photoluminescence of the PbWO 4 :La 3+ , Y 3+ (PWO II) crystal is investigated. • Creation of defects under UV irradiation of PWO II is studied by TSL. • Origin of dominating electron and hole centers is ascertained. • Concentration of single-vacancy-related centers is found to be negligible. • Excellent scintillation characteristics of the PWO II crystal are explained.

  8. Luminescent and scintillation properties of Sc3+and La3+doped Y2SiO5 powders and single crystalline films

    International Nuclear Information System (INIS)

    Zorenko, Yu.; Gorbenko, V.; Zorenko, T.; Voznyak, T.; Voloshynovskii, A.; Vistovskiy, V.; Paprocki, K.; Mosińska, L.; Bilski, P.; Twardak, A.; Fedorov, A.; Nikl, M.; Mares, J.A.

    2016-01-01

    The paper is dedicated to the investigation of the luminescence of Sc 3+ and La 3+ isoelectronic impurities in Y 2 SiO 5 (YSO) single crystalline films (SCF), grown by the liquid phase epitaxy (LPE) method, and in the powder analogs of these compounds prepared using the ceramic technology. The Sc 3+ and La 3+ dopants replacing the Y 3+ cations in Y1and Y2 positions of YSO host introduce the strong complex emission bands in the UV range peaked at 330 and 345 nm, respectively. The Sc 3+ and La 3+ dopant in YSO matrix yields also the strong TSL peaks at 400 and 405 K related to the ScY and ScLa centers formation, respectively. The luminescence and scintillation properties of YSO SCFs doped with Sc 3+ and La 3+ ions and co-doped with Ce 3+ ions on the trace impurity level have been also studied in our work. We have found that the light yield (LY) of these YSO:Sc and YSO:La SCFs can reach 50–65% of LY in reference YSO:Ce SCF due to strong quenching influence of Pb 2+ ions. Finally, the potential of Sc 3+ and La 3+ doped SCF of orthosilicates for creation of heavy scintillation screens, emitting in the UV range, is discussed.

  9. Preparation and determination of the luminescent characteristics of ZrO{sub 2} in powder; Preparacion y determinacion de las caracteristicas luminiscentes del ZrO{sub 2} en polvo

    Energy Technology Data Exchange (ETDEWEB)

    Rivera M, T. [ESIME-IPN Unidad Culhuacan Mexico D.F. (Mexico); Olvera T, L.; Azorin N, J.; Soto E, A.M.; Velazquez O, C.; Campero C, A. [UAM-I, 09340 Mexico D.F. (Mexico)

    2004-07-01

    In this work the luminescent characteristics of the ZrO{sub 2} are presented using the method of Thermally Stimulated Luminescence (TSL), also called thermoluminescence (Tl). The powders of ZrO{sub 2} were obtained by two preparation methods: for precipitation and for evaporation of Sol-gel. The luminescent characteristics of the ZrO{sub 2} are determined using a lamp of radiation of UV light and a radiation source of beta particles of {sup 90}Sr/{sup 90}Y. Using the method of thermal stimulation the curve representative thermoluminescent of the previously irradiated material was obtained. The curve Tl of the ZrO{sub 2} irradiated with UV light presents a maximum in 180 C. Likewise, the spectrum of the curve Tl of the ZrO{sub 2} irradiated with particles beta presents a maximum centered in 181 C. While using gamma radiation like excitement source one has a spectrum with a peak centered in 184 C. When subjecting the materials obtained by sol-gel to a process of calcination at 1000 C for 24 hours a curved Tl it presents with two maxim in 185 and in 290 C respectively. The intensity of the response induced in the material it is a decisive factor to continue studying the dosimetric characteristics of the ZrO{sub 2} what allows to consider it as a potential material to use it in the beta particle dosimetry and of the UV light using the thermoluminescence method (Tl). (Author)

  10. Dosimeter properties of Ce and Eu doped LiCaAlF6

    International Nuclear Information System (INIS)

    Yanagida, Takayuki; Fujimoto, Yutaka; Watanabe, Kenichi; Fukuda, Kentaro

    2014-01-01

    Optical, scintillation properties, optical stimulated luminescence, and thermally stimulated luminescence of Ce 1, 3, and 5% doped and Eu 1, 1.5, and 2% doped LiCaAlF 6 crystals fabricated by Tokuyama Corp. were investigated. In transmittance, absorption was proportional to dopant concentrations and typical optical quantum yield of Ce and Eu-doped LiCaAlF 6 were 40 and 100%, respectively. Scintillation wavelength and decay time profiles were investigated under X-ray irradiation. Ce 3+ and Eu 2+ 5d-4f luminescence appeared around 300 nm and 370 nm with typical decay time of 40 ns and 1.5 μs, respectively. Optically stimulated luminescence of Ce-doped ones appeared under 405 nm stimulation with detectable intensity while those of Eu doped ones were quite weak. Thermally stimulated luminescence of Ce- and Eu-doped LiCaAlF 6 were enough strong and they exhibited good response function from 1 to 1000 mGy exposure. - Highlights: • Optical, scintillation, OSL, and TSL properties of Ce or Eu differently doped LiCaAlF6 were studied. • PL quantum yield of Ce and Eu doped LiCaAlF6 showed 40% and 100%, respectively. • OSL was observed in Ce-doped LiCaAlF6. • TSL was observed in both material systems and exhibited a good dose response from 1 to 1000 mGy

  11. Luminescence and photothermally stimulated defects creation processes in PbWO{sub 4}:La{sup 3+}, Y{sup 3+} (PWO II) crystals

    Energy Technology Data Exchange (ETDEWEB)

    Auffray, E. [CERN, Geneva 23, Geneva (Switzerland); Korjik, M. [Institute for Nuclear Problems, 11 Bobruiskaya, 220020 Minsk (Belarus); Zazubovich, S., E-mail: svetlana.zazubovits@ut.ee [Institute of Physics, University of Tartu, Ravila 14 c, 50411 Tartu (Estonia)

    2015-12-15

    Photoluminescence and thermally stimulated luminescence (TSL) are studied for a PbWO{sub 4} crystal grown by the Czochralski method at Bogoroditsk Technical Chemical Plant, Russia from the melt with a precise tuning of the stoichiometry and co-doped with La{sup 3+} and Y{sup 3+} ions (the PWO II crystal). Photothermally stimulated processes of electron and hole centers creation under selective UV irradiation of this crystal in the 3.5–5.0 eV energy range and the 85–205 K temperature range are clarified and the optically created electron and hole centers are identified. The electrons in PWO II are mainly trapped at the (WO{sub 4}){sup 2−} groups located close to single La{sup 3+} and Y{sup 3+} ions, producing the electron {(WO_4)"3"−–La"3"+} and {(WO_4)"3"−–Y"3"+} centers. The holes are mainly trapped at the regular oxygen ions O{sup 2−} located close to La{sup 3+} and Y{sup 3+} ions associated with lead vacancies, producing the hole O{sup −}(I)-type centers. No evidence of single-vacancy-related centers has been observed in PWO II. The data obtained indicate that excellent scintillation characteristics of the PWO II crystal can be explained by a negligible concentration of single (non-compensated) oxygen and lead vacancies as the traps for electrons and holes, respectively. - Highlights: • Photoluminescence of the PbWO{sub 4}:La{sup 3+}, Y{sup 3+} (PWO II) crystal is investigated. • Creation of defects under UV irradiation of PWO II is studied by TSL. • Origin of dominating electron and hole centers is ascertained. • Concentration of single-vacancy-related centers is found to be negligible. • Excellent scintillation characteristics of the PWO II crystal are explained.

  12. Luminescence dating

    International Nuclear Information System (INIS)

    Rieser, U.

    2013-01-01

    The luminescence techniques have evolved over the last 40 years to a powerful dating instrument in archaeology and geoscience. Depending on how the luminescence is stimulated, one distinguishes the phenomena of thermoluminescence (TL), optically stimulated luminescence (OSL) and infrared stimulated luminescence (IRSL). Each of these phenomena has its specific potential for dating various archaeological materials in the time range from medieval back to palaeolithic periods, or, speaking in geological terms, for dating of Holocene and late Pleistocene objects. The OSL and IRSL techniques are sometimes treated together as 'optical dating'. The luminescence techniques differ from other major dating techniques, such as 14 C, essentially by their applicability to inorganic materials, their wide age-range from about 100 years to more than 100,000 years and the kind of datable events which are the last exposure to heat or to light. (author). 10 refs., 3 figs.

  13. Luminescence dating

    International Nuclear Information System (INIS)

    Rieser, U.

    2009-01-01

    The luminescence techniques have evolved over the last 40 years to a powerful dating instrument in archaeology and geoscience. Depending on how the luminescence is stimulated, one distinguishes the phenomena of thermoluminescence (TL), optically stimulated luminescence (OSL) and infrared stimulated luminescence (IRSL). Each of these phenomena has its specific potential for dating various archaeological materals in the time range from medieval back to palaeolithic periods, or, speaking in geological terms, for dating of Holocene and late Pleistocene objects. The OSL and IRSL techniques are sometimes treated together as 'optical dating'. The luminescence techniques differ from other major dating techniques, such as 14 C, essentially by their applicability to inorganic materials, their wide age-range from about 100 years to more than 100,000 years and the kind of datable events which are the last exposure to heat or to light. (author). 10 refs., 3 figs.

  14. Luminescence dating

    International Nuclear Information System (INIS)

    Rieser, U.

    2008-01-01

    The luminescence techniques have evolved over the last 40 years to a powerful dating instrument in archaeology and geoscience. Depending on how the luminescence is stimulated, one distinguishes the phenomena of thermoluminescence (TL), optically stimulated luminescence (OSL) and infrared stimulated luminescence (IRSL). Each of these phenomena has its specific potential for dating various archaeological materals in the time range from medieval back to palaeolithic periods, or, speaking in geological terms, for dating of Holocene and late Pleistocene objects. The OSL and IRSL techniques are sometimes treated together as 'optical dating'. The luminescence techniques differ from other major dating techniques, such as 14 C, essentially by their applicability to inorganic materials, their wide age-range from about 100 years to more than 100,000 years and the kind of datable events which are the last exposure to heat or to light. (author). 10 refs., 3 figs

  15. Luminescence dating

    International Nuclear Information System (INIS)

    Rieser, U.

    2012-01-01

    The luminescence techniques have evolved over the last 40 years to a powerful dating instrument in archaeology and geoscience. Depending on how the luminescence is stimulated, one distinguishes the phenomena of thermoluminescence (TL), optically stimulated luminescence (OSL) and infrared stimulated luminescence (IRSL). Each of these phenomena has its specific potential for dating various archaeological materials in the time range from medieval back to palaeolithic periods, or, speaking in geological terms, for dating of Holocene and late Pleistocene objects. The OSL and IRSL techniques are sometimes treated together as 'optical dating'. The luminescence techniques differ from other major dating techniques, such as 14 C, essentially by their applicability to inorganic materials, their wide age-range from about 100 years to more than 100,000 years and the kind of datable events which are the last exposure to heat or to light. (author). 10 refs., 3 figs.

  16. Luminescence dating

    International Nuclear Information System (INIS)

    Rieser, U.

    2009-01-01

    The luminescence techniques have evolved over the last 40 years to a powerful dating instrument in archaeology and geoscience. Depending on how the luminescence is stimulated, one distinguishes the phenomena of thermoluminescence (TL), optically stimulated luminescence (OSL) and infrared stimulated luminescence (IRSL). Each of these phenomena has its specific potential for dating various archaeological materals in the time range from medieval back to palaeolithic periods, or, speaking in geological terms, for dating of Holocene and late Pleistocene objects. The OSL and IRSL techniques are sometimes treated together as 'optical dating'. The luminescence techniques differ from other major dating techniques, such as 14 C, essentially by their applicability to inorganic materials, their wide age-range from about 100 years to more than 100,000 years and the kind of datable events which are the last exposure to heat or to light. (author). 10 refs., 3 figs

  17. Luminescence and energy transfer

    Energy Technology Data Exchange (ETDEWEB)

    Blasse, G; Bleijenberg, K C; Powell, R C

    1980-01-01

    This paper deals with the luminescence of uranate centres in solids. The luminescence properties are influenced by the coordination number of the hexavalent uranium ion and by the crystallographic surroundings of the uranate centre. Transitions playing a role in the luminescence processes within the octahedral UO/sub 6//sup 6 -/ group are discussed using the results from both theoretical and experimental studies on another octahedral uranium complex: UF/sub 6/. The luminescence of the octahedral uranate group in oxidic compounds is discussed. Attention is paid to the vibrational structure, which is observed in the luminescence spectra at low temperatures and to the temperature quenching of the luminescence. The temperature quenching of the uranate luminescence in uranium-doped tungstates with ordered perovskite structure can be described in terms of a three state single configurational coordinate diagram. The complicated luminescence spectra of uranium-activated sodium fluoride (NaF-U) crystals have been unraveled using chemical variation of the crystal compositions and using site selective laser excitation techniques. Four different luminescent uranate centres have been observed in NaF-U. A model for the configurations of the luminescent centres has been deduced using the results from ionic conductivity experiments.

  18. On the nature of capture centers in irradiated ceramics SK-1

    International Nuclear Information System (INIS)

    Ashurov, M.Kh.; Gasanov, E.M.; Kim, Gen Chan; Nuritdinov, I.; Saidahmedov, Kh.

    2006-01-01

    Full text: Along with other methods, for detection of radiation defects, the luminescent methods are widely used. One of such methods is the thermo-stimulated luminescence (TSL) method. By using this method, information on nature and energy depth (E c ) of capture centers can be obtained. In this work, the influence of high dose γ--irradiation on magnesial ceramics SK-1 was studied by the TL method. The samples were irradiated with ' 60 Co source, and the γ-irradiation dose varied between 10 4 and 10 10 R. The TL curves were measured in the temperature ranges from 80 to 700 K. As a result of irradiation the samples acquired brown colour. After γ-irradiation one can see the peak with maximum of 220 K and the peaks with 428, 548 and 658 K in the low-temperature ( 300 K) regions of the TL curves, respectively. To determine the nature of capture centers the samples were annealed in the air-conditions environment. Annealing conditions do not lead to changes in intensities of the existing TL peaks. After heat treatment in air the increase in intensity of 220, 428 and 548 K of TLS peaks can be observed, whereas in 10-hour treatment the saturation can be observed. Besides, the TL peaks at 353-363 K appears. Consequent restoring annealing decreases intensities of 220, 428 and 548 K and leads to disappearing peaks at 353-363 K. The energy depth values E c calculated by the Uhrbach formula E c =T, K/500 occurred to be : 0,44 eV; 0,86 eV and 1,096 eV for 220, 428 and 548 K, respectively. Besides, at annealing the increase of reflection characteristics of ceramics samples within 300-700 nm in observed, whereas the reflection intensities fall for the samples undergone the annealing. The analysis of the experimental results demonstrated that 220, 428 and 548 K peaks and additional absorption in the region of 300-700 nm are conditioned by V-centers. Possible mechanisms of CC formation and improvement of explanation characteristics of SK-1 ceramics in the ionization fields are

  19. LiCaAlF sub 6 :Ce crystal: a new scintillator

    CERN Document Server

    Gektin, A V; Neicheva, S; Gavrilyuk, V; Bensalah, A; Fukuda, T; Shimamura, K

    2002-01-01

    Scintillation properties of LiCaAlF sub 6 :Ce crystal, well known as the effective UV laser material, is reported. Ce sup 3 sup + emission at 286-305 nm with a single exponential decay time of 35 ns provides a scintillation pulse. Radiation damage in pure and Ce-doped crystals is studied. In contrast to the majority of fluoride crystals, cerium is responsible for the ultradeep traps formation revealing thermostimulated luminescence. Overlapping of color center absorption and Ce sup 3 sup + ion emission bands limits the scintillation efficiency of LiCaAlF sub 6 :Ce at high radiation doses.

  20. Luminescent beam stop

    Energy Technology Data Exchange (ETDEWEB)

    Bryant, Diane; Morton, Simon A.

    2017-10-25

    This disclosure provides systems, methods, and apparatus related to beam stops. In one aspect, a device comprises a luminescent material, a beam stop plate, and an optical fiber. The luminescent material is a parallelepiped having a first side and a second side that are squares and having a third side that is a rectangle or a square. The first side and the second side are perpendicular to the third side. The beam stop plate is attached to the first side of the luminescent material. The optical fiber has a first end and a second end, with the first end of the optical fiber attached to the third side of the luminescent material.

  1. Determination of the dose of gamma radiation sterilization for assessment of biological parameters of male Ceratitis capitada (Diptera: Tephritidae), tsl - Vienna 8 strain; Determinacao da dose de radiacao gama esterilizante pela avaliacao dos parametros biologicos de machos de Ceratitis capitata (Diptera: Tephritidae), linhagem tsl - Vienna 8

    Energy Technology Data Exchange (ETDEWEB)

    Rocha, Aline Cristina Pereira da

    2011-07-01

    The Vienna-8, tsl (temperature sensitive lethal) strain of Ceratitis capitata, by presenting mutations that facilitate the mass rearing and release only of sterile males in the field, has been used in (Sterile Insect Technique) programmes. The objective of this study was to determine the radiation dose that provides the highest level of sterility for Vienna-8, tsl males assessing their biological parameters that indicate the quality of sterile males to be released. Brown pupae (males) of the tsl strain were obtained from the mass rearing of the Food Irradiation and Radio entomology laboratory of CENA/USP, and they were irradiated (with gamma radiation - {sup 60}Co) 24 hours before the emergence at rates of 0, 30, 60, 90 and 120 Gy. The determination of the sterilizing dose was based on fertility of sexually mature females of the bisexual strain and not irradiated, mated with males of different treatments. Eggs were collected daily during 6 days, were counted and it was possible to estimate fecundity, and assess the hatching rate. The emergence and flight ability were determined by following the protocol of quality control manual for FAO/IAEA/USDA (2003). To assess the longevity under nutritional stress, the insects were kept a period of 48 h after emergence in the absence of water and food, and after this period, mortality was recorded. The size of the testes (left and right) was obtained by dissecting irradiated and non-irradiated males at the eighth day of life, and measure the testes in an ocular micrometer, considering the maximum length and width of each sample. To determine the sperm number was necessary to dissect the males and break their testicles. No difference was observed in emergence rate, flight ability and longevity of irradiated and non-irradiated males, nor in the fecundity of females mated with males of different treatments. The sterilizing dose that resulted in lower fertility of females was 120 Gy, with 1.5% hatching. Considering the parameters

  2. Comparative study of scintillation properties of RE doped NaPO3-Al(PO3)3 glasses

    International Nuclear Information System (INIS)

    Kuro, Tomoaki; Yanagida, Takayuki; Okada, Go; Fujimoto, Yutaka; Masai, Hirokazu

    2015-01-01

    We systematically investigated photoluminescence (PL), scintillation and dosimeter properties of rare-earth (RE) doped NaPO 3 -Al(PO 3 ) 3 (NAP) glasses. Ag-doped NAP glass is widely used for individual radiation dosimeter, however, there have been few reports on studies about NAP glasses when RE ions are doped as the luminescence center. The NAP glasses doped with 0.3 wt% RE (La∼Yb) were prepared by the conventional melt-quenching method. PL decay time and scintillation decay time profiles showed fast (ns) and slow (μs or ms) components: the fast components were from several tens to 100 ns due to the host emission or 5d-4f transition emission, and the slow component from few μs to few ms was caused by 4f-4f transition emission of RE 3+ . Thermally stimulated luminescence (TSL) was evaluated as a dosimeter property, and glow peaks appeared around 400degC in all the samples. The TSL dose response function was examined in the dose range from 10 mGy to 10 Gy, and good linearity was observed in RE-doped NAP glasses. (author)

  3. Application of TSL Underwater Robots (AUV) for Investigation of Benthic Ecosystems and Quantification of Benthic Invertebrate Reserves

    Science.gov (United States)

    Golikov, S. Yu; Dulepov, V. I.; Maiorov, I. S.

    2017-11-01

    The issues on the application of autonomous underwater vehicles for assessing the abundance, biomass, distribution and reserves of invertebrates in the marine benthic ecosystems and on the environmental monitoring are discussed. An example of the application of methodology to assess some of the quantitative characteristics of macrobenthos is provided based upon using the information obtained from the TSL AUV in the Peter the Great Gulf (the Sea of Japan) in the Bay of Paris and the Eastern Bosphorus Strait within the area of the bridge leading to the Russian island. For the quantitative determination of the benthic invertebrate reserves, the values of biomass density of specific species are determined. Based on the data of direct measurements and weightings, the equations of weight dependencies on the size of animals are estimated according to the studied species that are well described by the power law dependence.

  4. Luminescence detection of shellfish

    International Nuclear Information System (INIS)

    Sanderson, D.C.W.; Carmichael, L.A.; Spencer, J.Q.; Naylor, J.D.

    1996-01-01

    The Scottish Universities Research and Reactor Centre (SURRC) has been active in the development and application of luminescence techniques in the detection of irradiated foods, in support of UK legislation. Thermoluminescence (TL), photostimulated luminescence (PSL) and photo-transfer luminescence (PTTL) are radiation-specific phenomena which arise due to energy stored by trapped charge carriers following irradiation. The energy released following stimulation is accompanied by detectable luminescence. The TL method involves preparation of pure silicate extracts from the sample and subsequent TL analysis, whereas PSL uses stimulation by electromagnetic radiation (visible, or near visible wavelengths) thus avoiding heating the sample. (author)

  5. Radiation defects in SrB4O7:Eu2+ crystals

    International Nuclear Information System (INIS)

    Yavetskiy, R.P.; Dolzhenkova, E.F.; Tolmachev, A.V.; Parkhomenko, S.V.; Baumer, V.N.; Prosvirnin, A.L.

    2007-01-01

    Radiation-induced defects in SrB 4 O 7 :Eu 2+ (0.033 at.%) single crystal irradiated with γ and X-ray quanta has been studied. The induced optical absorption in the 400-700 nm region has been ascribed to F + centers. The Eu 2+ ions have been shown to act simultaneously as traps and as radiative recombination centers of charge carriers. Basing on the thermally stimulated luminescence (TSL), optical absorption and photoluminescence studies of SrB 4 O 7 :Eu 2+ crystals, a TSL mechanism has been proposed associated with the decay of F + centers being in non-equivalent crystallographic positions followed by radiative recombination of charge carriers on europium ions. Various positions of localization of the radiation-induced defects in the SrB 4 O 7 crystal structure have been discussed

  6. Existence of the uranyl ion at regular Sr site in U doped SrBPO5

    International Nuclear Information System (INIS)

    Mithlesh Kumar; Mohapatra, M.; Natarajan, V.

    2014-01-01

    Actinide doped alkaline earth borophosphates of the general formula MBPO 5 (M = Ca 2+ , Sr 2+ , Ba 2+ ) are of special interest due to array of defect centers that can be generated in these compounds by internal (α and γ) irradiation effects. Further, the crystalline alkaline earth borophosphates are also reported to be isostructural with stillwellite-LnBSiO 5 , which are built up by BO 4 and SiO 4 tetrahedra. This structure suggests that the host MBPO 5 should be a good matrix for luminescence investigations for suitable activator ions. The important advantages of MBPO 5 type systems are their high luminescence, moderate preparation temperature and low thermal degradation. XRD pattern of the prepared phosphor confirmed the formation of SrBPO 5 in a single phase. The presence of uranium in SrBPO 5 sample was ascertained from Energy Dispersive X-ray Fluorescence (EDXRF) measurements performed on a Jordan Valley instrument. The U content in the sample was found to be about 0.85%. An Inductively Coupled Plasma Atomic Emission Spectrometric (ICP-AES), Jobin Yvon, France was used for analysis of the sample, which showed all other metallic impurities except U to be present at concentrations below 5 :U, PL, TSL and ESR studies were conducted on the solid state route samples. PL and TSL techniques were used with a view to understand the species responsible for the luminescence and its site symmetry

  7. Positron-Induced Luminescence

    Science.gov (United States)

    Stenson, E. V.; Hergenhahn, U.; Stoneking, M. R.; Pedersen, T. Sunn

    2018-04-01

    We report on the observation that low-energy positrons incident on a phosphor screen produce significantly more luminescence than electrons do. For two different wide-band-gap semiconductor phosphors (ZnS:Ag and ZnO:Zn), we compare the luminescent response to a positron beam with the response to an electron beam. For both phosphors, the positron response is significantly brighter than the electron response, by a factor that depends strongly on incident energy (0-5 keV). Positrons with just a few tens of electron-volts of energy (for ZnS:Ag) or less (for ZnO:Zn) produce as much luminescence as is produced by electrons with several kilo-electron-volts. We attribute this effect to valence band holes and excited electrons produced by positron annihilation and subsequent Auger processes. These results demonstrate a valuable approach for addressing long-standing questions about luminescent materials.

  8. Luminescence from metals and insulators

    International Nuclear Information System (INIS)

    Crawford, O.H.

    1985-01-01

    The term luminescence is normally applied to light emission that is not explainable by the mechanisms discussed by the other speakers in this meeting. Specifically, it is not transition radiation, surface plasmon radiation, or bremsstrahlung. One normally thinks of luminescence as arising from one-electron transitions within a medium. This talk consists of an overview of luminescence from condensed matter under irradiation by either energetic particles or photons. The author begins with organic molecules, where luminescence is best understood, and then discusses inorganic insulators and metals. Finally, the dependence of yield upon projectile species and velocity is discussed, and predictions are made concerning the relative effectiveness of electrons, protons, and hydrogen atoms in exciting luminescence

  9. Resonance-shifting luminescent solar concentrators

    Energy Technology Data Exchange (ETDEWEB)

    Giebink, Noel Christopher; Wiederrecht, Gary P.; Wasielewski, Michael R.

    2018-01-23

    An optical system and method to overcome luminescent solar concentrator inefficiencies by resonance-shifting, in which sharply directed emission from a bi-layer cavity into a glass substrate returns to interact with the cavity off-resonance at each subsequent reflection, significantly reducing reabsorption loss en route to the edges. In one embodiment, the system comprises a luminescent solar concentrator comprising a transparent substrate, a luminescent film having a variable thickness; and a low refractive index layer disposed between the transparent substrate and the luminescent film.

  10. Feldspar, Infrared Stimulated Luminescence

    DEFF Research Database (Denmark)

    Jain, Mayank

    2014-01-01

    This entry primarily concerns the characteristics and the origins of infrared-stimulated luminescence in feldspars.......This entry primarily concerns the characteristics and the origins of infrared-stimulated luminescence in feldspars....

  11. Time-resolved measurements of luminescence

    Energy Technology Data Exchange (ETDEWEB)

    Collier, Bradley B. [Department of Biomedical Engineering, 408 Mechanical Engineering Office Building, Spence Street, Texas A and M University, College Station, TX 77843 (United States); McShane, Michael J., E-mail: mcshane@tamu.edu [Department of Biomedical Engineering, 408 Mechanical Engineering Office Building, Spence Street, Texas A and M University, College Station, TX 77843 (United States); Materials Science and Engineering Program, 408 Mechanical Engineering Office Building, Spence Street, Texas A and M University, College Station, TX 77843 (United States)

    2013-12-15

    Luminescence sensing and imaging has become more widespread in recent years in a variety of industries including the biomedical and environmental fields. Measurements of luminescence lifetime hold inherent advantages over intensity-based response measurements, and advances in both technology and methods have enabled their use in a broader spectrum of applications including real-time medical diagnostics. This review will focus on recent advances in analytical methods, particularly calculation techniques, including time- and frequency-domain lifetime approaches as well as other time-resolved measurements of luminescence. -- Highlights: • Developments in technology have led to widespread use of luminescence lifetime. • Growing interest for sensing and imaging applications. • Recent advances in approaches to lifetime calculations are reviewed. • Advantages and disadvantages of various methods are weighed. • Other methods for measurement of luminescence lifetime also described.

  12. Time-resolved measurements of luminescence

    International Nuclear Information System (INIS)

    Collier, Bradley B.; McShane, Michael J.

    2013-01-01

    Luminescence sensing and imaging has become more widespread in recent years in a variety of industries including the biomedical and environmental fields. Measurements of luminescence lifetime hold inherent advantages over intensity-based response measurements, and advances in both technology and methods have enabled their use in a broader spectrum of applications including real-time medical diagnostics. This review will focus on recent advances in analytical methods, particularly calculation techniques, including time- and frequency-domain lifetime approaches as well as other time-resolved measurements of luminescence. -- Highlights: • Developments in technology have led to widespread use of luminescence lifetime. • Growing interest for sensing and imaging applications. • Recent advances in approaches to lifetime calculations are reviewed. • Advantages and disadvantages of various methods are weighed. • Other methods for measurement of luminescence lifetime also described

  13. Determination of the dose of gamma radiation sterilization for assessment of biological parameters of male Ceratitis capitada (Diptera: Tephritidae), tsl - Vienna 8 strain

    International Nuclear Information System (INIS)

    Rocha, Aline Cristina Pereira da

    2011-01-01

    The Vienna-8, tsl (temperature sensitive lethal) strain of Ceratitis capitata, by presenting mutations that facilitate the mass rearing and release only of sterile males in the field, has been used in (Sterile Insect Technique) programmes. The objective of this study was to determine the radiation dose that provides the highest level of sterility for Vienna-8, tsl males assessing their biological parameters that indicate the quality of sterile males to be released. Brown pupae (males) of the tsl strain were obtained from the mass rearing of the Food Irradiation and Radio entomology laboratory of CENA/USP, and they were irradiated (with gamma radiation - 60 Co) 24 hours before the emergence at rates of 0, 30, 60, 90 and 120 Gy. The determination of the sterilizing dose was based on fertility of sexually mature females of the bisexual strain and not irradiated, mated with males of different treatments. Eggs were collected daily during 6 days, were counted and it was possible to estimate fecundity, and assess the hatching rate. The emergence and flight ability were determined by following the protocol of quality control manual for FAO/IAEA/USDA (2003). To assess the longevity under nutritional stress, the insects were kept a period of 48 h after emergence in the absence of water and food, and after this period, mortality was recorded. The size of the testes (left and right) was obtained by dissecting irradiated and non-irradiated males at the eighth day of life, and measure the testes in an ocular micrometer, considering the maximum length and width of each sample. To determine the sperm number was necessary to dissect the males and break their testicles. No difference was observed in emergence rate, flight ability and longevity of irradiated and non-irradiated males, nor in the fecundity of females mated with males of different treatments. The sterilizing dose that resulted in lower fertility of females was 120 Gy, with 1.5% hatching. Considering the parameters of

  14. Advantages and disadvantages of luminescence dosimetry

    Energy Technology Data Exchange (ETDEWEB)

    Olko, Pawel, E-mail: Pawel.Olko@ifj.edu.p [Institute of Nuclear Physics Polish Academy of Science (IFJ PAN), Krakow (Poland)

    2010-03-15

    Owing to their excellent dosimetric properties, luminescence detectors of ionizing radiation are now extensively applied in individual dosimetry services. The most frequently used personal dosemeters are based on Optically Stimulated Luminescence (OSL), radiophotoluminescence (RPL) or thermoluminescence (TL). Luminescence detectors have also found several applications in clinical dosimetry, especially around new radiation modalities in radiotherapy, such as Intensity Modulated Radiotherapy (IMRT) or ion beam radiotherapy. Requirements of luminescence detectors applied in individual and clinical dosimetry and some recent developments in luminescence of detectors and techniques leading to significant improvements of the functionality and accuracy of dosimetry systems are reviewed and discussed.

  15. Near white light emitting ZnAl2O4:Dy3+ nanocrystals: Sol–gel synthesis and luminescence studies

    International Nuclear Information System (INIS)

    Kumar, Mithlesh; Gupta, Santosh K.; Kadam, R.M.

    2016-01-01

    Highlights: • ZnAl 2 O 4 :Dy 3+ spinel synthesized using sol–gel method. • Characterized by XRD, SEM and PL spectroscopy. • Investigations of emission, excitation and lifetime properties. • Evaluation of defect centers and trap parameters of the system. • Evaluation of CIE indices of near white light emitting phosphor. - Abstract: ZnAl 2 O 4 :Dy 3+ nanoparticles were synthesized using citrate sol–gel method and characterized systematically using X-ray diffraction, scanning electron microscopy and photoluminescence spectroscopy. Emission spectrum of pure ZnAl 2 O 4 shows intense violet blue emission under ultra violet irradiation. Based on electron paramagnetic resonance (EPR) results; it was attributed to presence of singly ionized oxygen vacancy centres in ZnAl 2 O 4 . On doping Dy 3+ in ZnAl 2 O 4 , complete host–dopant energy transfer does not take place. Local structural investigation and lifetime measurements reveal that dysprosium ion is distributed between both Zn 2+ and Al 3+ sites. Near white light from ZnAl 2 O 4 :Dy 3+ is attributed to combined host and dopant luminescence. The trap parameters such as activation energy (E) and frequency factor (s) for TSL glow peak 165 °C were determined using different heating rate method. Thermally stimulated emission showed the presence of oxygen related defect centre.

  16. Seismic Moment and Recurrence using Luminescence Dating Techniques: Characterizing brittle fault zone materials suitable for luminescence dating

    Science.gov (United States)

    Tsakalos, E.; Lin, A.; Bassiakos, Y.; Kazantzaki, M.; Filippaki, E.

    2017-12-01

    During a seismic-geodynamic process, frictional heating and pressure are generated on sediments fragments resulting in deformation and alteration of minerals contained in them. The luminescence signal enclosed in minerals crystal lattice can be affected and even zeroed during such an event. This has been breakthrough in geochronological studies as it could be utilized as a chronometer for the previous seismic activity of a tectonically active area. Although the employment of luminescence dating has in some cases been successfully described, a comprehensive study outlining and defining protocols for routine luminescence dating applied to neotectonic studies has not been forthcoming. This study is the experimental investigation, recording and parameterization of the effects of tectonic phenomena on minerals luminescence signal and the development of detailed protocols for the standardization of the luminescence methodology for directly dating deformed geological formations, so that the long-term temporal behaviour of seismically active faults could be reasonably understood and modeled. This will be achieved by: a) identifying and proposing brittle fault zone materials suitable for luminescence dating using petrological, mineralogical and chemical analyses and b) investigating the "zeroing" potential of the luminescence signal of minerals contained in fault zone materials by employing experimental simulations of tectonic processes in the laboratory, combined with luminescence measurements on samples collected from real fault zones. For this to be achieved, a number of samples collected from four faults of four different geographical regions will be used. This preliminary-first step of the study presents the microstructural, and mineralogical analyses for the characterization of brittle fault zone materials that contain suitable minerals for luminescence dating (e.g., quartz and feldspar). The results showed that the collected samples are seismically deformed fault

  17. Metal plasmon enhanced europium complex luminescence

    International Nuclear Information System (INIS)

    Liu Feng; Aldea, Gabriela; Nunzi, Jean-Michel

    2010-01-01

    The plasmon enhanced luminescence of a rare-earth complex Tris(6, 6, 7, 7, 8, 8, 8-heptafluoro-2, 2-dimethyl-3, 5-octanedionato) europium (Eu(fod) 3 ) was investigated. A polyvinyl alcohol (PVA) thin film was successfully adopted as a spacer to separate the Eu complex from the silver island film (SIF), and five-fold enhancement of the radiative decay rate of the Eu complex on SIF was demonstrated based on the luminescence intensity and lifetime measurement. Investigation of the distance dependent luminescence indicates that 7 nm is an optimal distance for SIF enhanced Eu luminescence. Plasmon enhanced rare-earth luminescence based on an organic film spacer would find potential applications in plasmon enhanced organic light emitting diode (OLED) devices.

  18. Investigation into scanning tunnelling luminescence microscopy

    International Nuclear Information System (INIS)

    Manson-Smith, S.K.

    2001-01-01

    This work reports on the development of a scanning tunnelling luminescence (STL) microscope and its application to the study of Ill-nitride semiconductor materials used in the production of light emitting devices. STL microscopy is a technique which uses the high resolution topographic imaging capabilities of the scanning tunnelling microscope (STM) to generate high resolution luminescence images. The STM tunnelling current acts as a highly localised source of electrons (or holes) which generates luminescence in certain materials. Light generated at the STM tunnelling junction is collected concurrently with the height variation of the tunnelling probe as it is scanned across a sample surface, producing simultaneous topographic and luminescence images. Due to the very localised excitation source, high resolution luminescence images can be obtained. Spectroscopic resolution can be obtained by using filters. Additionally, the variation of luminescence intensity with tunnel current and with bias voltage can provide information on recombination processes and material properties. The design and construction of a scanning tunnelling luminescence microscope is described in detail. Operating under ambient conditions, the microscope has several novel features, including a new type of miniature inertial slider-based approach motor, large solid-angle light collection optical arrangement and a tip-height regulation system which requires the minimum of operator input. (author)

  19. Polymeric Luminescent Compositions Doped with Beta-Diketonates Boron Difluoride as Material for Luminescent Solar Concentrator

    Science.gov (United States)

    Khrebtov, A. A.; Fedorenko, E. V.; Reutov, V. A.

    2017-11-01

    In this paper we investigated polymeric luminescent compositions based on polystyrene doped with beta diketonates boron difluoride. Transparent films with effective absorption in the ultraviolet and blue regions of the spectrum were obtained. Polymeric luminescent compositions based on the mixture of dyes allow expanding the absorption region and increase the radiation shift. A luminescent solar concentrator consisting of a glass plate coated with such film can be used for photovoltaic window application.

  20. Luminescence sensitivity changes in quartz

    CERN Document Server

    Wintle, A G

    1999-01-01

    In the luminescence dating of sedimentary or heated quartz, some heat treatment is usually applied to the sample immediately prior to the measurement of the optically stimulated luminescence. In this paper we report experiments on a 30,000-year-old sedimentary quartz, in which we use the luminescence response to a test dose to monitor the changes in sensitivity that are caused by holding the quartz at temperatures from 160 to 280 deg. C for times from 10 s to 22 h. For an optically bleached sample, the monitoring is by both optically stimulated luminescence and the 110 deg. C TL peak; both luminescence signals are shown to have the same sensitisation (i.e. activation energy) characteristics. For natural or laboratory irradiated samples only the 110 deg. C TL peak can be used; sensitivity increases of up to a factor of 1.3 and 3 are observed for the natural and laboratory irradiated aliquots, respectively. Up to four exponential components are used to deconvolve the sensitivity change data; the dominant compon...

  1. Luminescence in medical image science

    Energy Technology Data Exchange (ETDEWEB)

    Kandarakis, I.S., E-mail: kandarakis@teiath.gr

    2016-01-15

    Radiation detection in Medical Imaging is mostly based on the use of luminescent materials (scintillators and phosphors) coupled to optical sensors. Materials are employed in the form of granular screens, structured (needle-like) crystals and single crystal transparent blocks. Storage phosphors are also incorporated in some x-ray imaging plates. Description of detector performance is currently based on quality metrics, such as the Luminescence efficiency, the Modulation Transfer Function (MTF), the Noise Power Spectrum (NPS) and the Detective Quantum Efficiency (DQE) can be defined and evaluated. The aforementioned metrics are experimental evaluated for various materials in the form of screens. A software was designed (MINORE v1) to present image quality measurements in a graphical user interface (GUI) environment. Luminescence efficiency, signal and noise analysis are valuable tools for the evaluation of luminescent materials as candidates for medical imaging detectors. - Highlights: • Luminescence based medical imaging detectors. • Image science: MTF, NPS, DQE. • Phosphors screens light emission efficiency experimental evaluation. • Theoretical models for estimation of phosphor screen properties. • Software for medical image quality metrics.

  2. Plasmon-enhanced optically stimulated luminescence

    International Nuclear Information System (INIS)

    Guidelli, E. J.; Baffa, O.; Ramos, A. P.

    2015-10-01

    Full text: Optically Stimulated Luminescence dosimeters (OSLD) have been largely used for personal, medical, and industrial radiation dosimetry. Developing highly sensitive and small-sized radiation detectors and dosimeters is essential for improving spatial resolution and consequently diagnosis quality and treatment efficacy in the case of applications in radiodiagnosis and radiation therapy, for instance. Conventional methods to improve the OSLD sensitivity consist of doping and co-doping the host materials with atoms of other elements, thereby increasing the amount of trapping and/or luminescent centers. Our group is researching on the use of the plasmon properties of noble metal nanoparticles to increase OSL intensity. Upon incidence of a light beam with appropriate resonant wavelengths, the oscillation of the free electrons at the nanoparticle surface originates the Localized Surface Plasmons (LSP) and the consequent plasmon resonance band. The interaction between the LSP and the surrounding luminescent material leads to new optical properties largely employed for enhancing several luminescent processes. Here we will show our results regarding the use of LSP to increase OSLD sensitivity. The interaction between the traps/luminescent centers and the plasmons depends on the distance between them, on the plasmon resonance band intensity and position, as well as on the surrounding medium. Therefore, the plasmon-enhanced luminescence is a promising tool to develop more sensitive and miniaturized OSLD. (Author)

  3. Plasmon-enhanced optically stimulated luminescence

    Energy Technology Data Exchange (ETDEWEB)

    Guidelli, E. J.; Baffa, O. [Universidade de Sao Paulo, Faculdade de Filosofia, Ciencias e Letras de Ribeirao Preto, Departamento de Fisica, Av. Bandeirantes 3900, 14040-901 Ribeirao Preto, Sao Paulo (Brazil); Ramos, A. P., E-mail: ederguidelli@gmail.com [Universidade de Sao Paulo, Faculdade de Filosofia, Ciencias e Letras de Ribeirao Preto, Departamento de Quimica, Av. Bandeirantes 3900, 14040-901 Ribeirao Preto, Sao Paulo (Brazil)

    2015-10-15

    Full text: Optically Stimulated Luminescence dosimeters (OSLD) have been largely used for personal, medical, and industrial radiation dosimetry. Developing highly sensitive and small-sized radiation detectors and dosimeters is essential for improving spatial resolution and consequently diagnosis quality and treatment efficacy in the case of applications in radiodiagnosis and radiation therapy, for instance. Conventional methods to improve the OSLD sensitivity consist of doping and co-doping the host materials with atoms of other elements, thereby increasing the amount of trapping and/or luminescent centers. Our group is researching on the use of the plasmon properties of noble metal nanoparticles to increase OSL intensity. Upon incidence of a light beam with appropriate resonant wavelengths, the oscillation of the free electrons at the nanoparticle surface originates the Localized Surface Plasmons (LSP) and the consequent plasmon resonance band. The interaction between the LSP and the surrounding luminescent material leads to new optical properties largely employed for enhancing several luminescent processes. Here we will show our results regarding the use of LSP to increase OSLD sensitivity. The interaction between the traps/luminescent centers and the plasmons depends on the distance between them, on the plasmon resonance band intensity and position, as well as on the surrounding medium. Therefore, the plasmon-enhanced luminescence is a promising tool to develop more sensitive and miniaturized OSLD. (Author)

  4. Luminescence of LiH(D):Ru monocrystals

    International Nuclear Information System (INIS)

    Sabirzyanov, A.A.; Oparin, D.V.; Pilipenko, G.I.; Gavrilov, F.F.

    1993-01-01

    Luminescence of lithium hydride (deuteride) activated by ruthenium is recorded for the first time. The features connected with the structure and oscillations of the basic lattice are detected in luminescence spectrum. The qualitative model of luminescence spectrum is suggested

  5. Uranyl fluoride luminescence in acidic aqueous solutions

    International Nuclear Information System (INIS)

    Beitz, J.V.; Williams, C.W.

    1996-01-01

    Luminescence emission spectra and decay rates are reported for uranyl species in acidic aqueous solutions containing HF or added NaF. The longest luminescence lifetime, 0.269 ± 0.006 ms, was observed from uranyl in 1 M HF + 1 M HClO 4 at 296 K and decreased with increasing temperature. Based on a luminescence dynamics model that assumes equilibrium among electronically excited uranyl fluoride species and free fluoride ion, this long lived uranyl luminescence in aqueous solution is attributed primarily to UO 2 F 2 . Studies on the effect of added LiNO 3 or Na 2 WO 4 ·2H 2 O showed relatively weak quenching of uranyl fluoride luminescence which suggests that high sensitivity determination of the UF 6 content of WF 6 gas should be feasible via uranyl luminescence analysis of hydrolyzed gas samples of impure WF 6

  6. Material for a luminescent solar concentrator

    Science.gov (United States)

    Andrews, L.J.

    1984-01-01

    A material for use in a luminescent solar concentrator, formed by ceramitizing the luminescent ion Cr/sup 3 +/ with a transparent ceramic glass containing mullite. The resultant material has tiny Cr/sup 3 +/-bearing crystallites dispersed uniformly through an amorphous glass. The invention combines the high luminescent efficiency of Cr/sup 3 +/ in the crystalline phase with the practical and economical advantages of glass technology.

  7. Virulence of luminescent and non-luminescent isogenic vibrios towards gnotobiotic Artemia franciscana larvae and specific pathogen-free Litopenaeus vannamei shrimp.

    Science.gov (United States)

    Phuoc, L H; Defoirdt, T; Sorgeloos, P; Bossier, P

    2009-04-01

    This study was conducted to test the virulence of luminescent (L) and non-luminescent (NL) isogenic strains of Vibrio campbellii LMG21363, Vibrio harveyi BB120 (wild type) and quorum-sensing mutant strains derived from the wild type such as Vibrio harveyi BB152, BB170, MM30 and BB886. The NL strains could be obtained by culturing rifampicin-resistant luminescent strains in the dark under static condition. The virulence of the L and NL strains was tested in gnotobiotic Artemia franciscana larvae challenged with 10(4) CFU ml(-1) of bacteria. All luminescent isogenic tested strains showed higher virulence compared to the NL strains. The virulence of L and NL V. campbellii and V. harveyi BB120 was also tested in specific pathogen-free juvenile shrimp upon intramuscular injection with 10(6) CFU of bacteria. In contrast with Artemia, there was no significant difference in mortality between the groups challenged with L and NL strains (P > 0.05). The non-luminescent strains were not able to revert back to the luminescent state and quorum sensing did not influence this phenotypic shift. Luminescent Vibrio strains can switch to a non-luminescent state by culturing them in static conditions. The NL strains become less virulent as verified in Artemia. The luminescent state of Vibrio cells in a culture needs to be verified in order to assure maintenance of virulence.

  8. Luminescence of uranyl ion complexed with 2,6-pyridine dicarboxylic acid as ligand in acetonitrile medium. Observation of co-luminescence

    Energy Technology Data Exchange (ETDEWEB)

    Maji, Siuli; Kumar, Satendra; Sankaran, Kannan [Indira Ghandi Centre for Atomic Research, Tamil Nadu (India). Materials Chemistry Div.

    2017-10-01

    Luminescence from UO{sub 2}{sup 2+} (uranyl ion) complexed with 2,6-pyridine dicarboxylic acid (PDA) has been studied using acetonitrile (MeCN) as solvent between pH 1.0 and 6.0. The enhancement in luminescence intensity because of sensitization by PDA in the non-aqueous environment provided by the MeCN is found to be one order better than in aqueous medium. The luminescence is further enhanced by about four times following the addition of Y{sup 3+}; a process known as co-luminescence. This is the first study on co-luminescence of uranyl ion in its PDA complex. Lifetime studies indicate the presence of two species having different micro-environments. Formations of both intra and inter molecular complexes are believed to be responsible for enhancement due to co-luminescence.

  9. Luminescence of uranyl ion complexed with 2,6-pyridine dicarboxylic acid as ligand in acetonitrile medium. Observation of co-luminescence

    International Nuclear Information System (INIS)

    Maji, Siuli; Kumar, Satendra; Sankaran, Kannan

    2017-01-01

    Luminescence from UO_2"2"+ (uranyl ion) complexed with 2,6-pyridine dicarboxylic acid (PDA) has been studied using acetonitrile (MeCN) as solvent between pH 1.0 and 6.0. The enhancement in luminescence intensity because of sensitization by PDA in the non-aqueous environment provided by the MeCN is found to be one order better than in aqueous medium. The luminescence is further enhanced by about four times following the addition of Y"3"+; a process known as co-luminescence. This is the first study on co-luminescence of uranyl ion in its PDA complex. Lifetime studies indicate the presence of two species having different micro-environments. Formations of both intra and inter molecular complexes are believed to be responsible for enhancement due to co-luminescence.

  10. Receptor-Targeted Luminescent Silver Bionanoparticles

    NARCIS (Netherlands)

    Bunschoten, Anton; Chin, Patrick T.K.; Buckle, Tessa; Linden, van der Marte; Barendregt, Arjan; Verheijen, Marcel A.; Leeuwen, van Fijs W.B.

    2016-01-01

    Luminescent Ag nanoclusters (Ag-NC) provide the next generation in bionanoparticles, wherein the luminescence (650 nm) and large Stokes shift of these inorganic nanoclusters are favorable for biological imaging. By combining these characteristics with those of human serum albumin (HSA; a protein

  11. Reflection measurements for luminescent powders

    Science.gov (United States)

    Kroon, R. E.

    2018-04-01

    Luminescent materials are useful in applications varying from lighting and display technologies to document security features and medical research, amongst many others. Measurement of the excitation range is an important consideration, and absorption bands are often determined from a decrease in the measured diffuse reflectance of the material using a ultraviolet-visible (UV-vis) spectrophotometer with an integrating sphere. Such a system may provide questionable results when used to measure the reflectance of a luminescence material, which is demonstrated for a Tb doped silica phosphor, because the system cannot differentiate between the reflected light and luminescence. It is shown that more reliable results are achieved for this phosphor by measuring the reflectance using a synchronous zero-offset scan in a fluorescence spectrometer equipped with an integrating sphere. This method is therefore recommended instead of traditional reflectance measurements using a UV-vis spectrophotometer for luminescent powders.

  12. Near-Infrared Quantum Cutting Long Persistent Luminescence

    OpenAIRE

    Zou, Zehua; Feng, Lin; Cao, Cheng; Zhang, Jiachi; Wang, Yuhua

    2016-01-01

    By combining the unique features of the quantum cutting luminescence and long persistent luminescence, we design a new concept called ?near-infrared quantum cutting long persistent luminescence (NQPL)?, which makes it possible for us to obtain highly efficient (>100%) near-infrared long persistent luminescence in theory. Guided by the NQPL concept, we fabricate the first NQPL phosphor Ca2Ga2GeO7:Pr3+,Yb3+. It reveals that both the two-step energy transfer of model (I) and the one-step energy ...

  13. Enhancing and quenching luminescence with gold nanoparticle films: the influence of substrate on the luminescent properties

    International Nuclear Information System (INIS)

    Guidelli, Eder José; Baffa, Oswaldo; Ramos, Ana Paula

    2016-01-01

    Gold nanoparticle (AuNP) films were sputtered over glass and aluminum substrates to enhance optically stimulated luminescence (OSL), a luminescent technique employed for radiation detection, from x-ray irradiated NaCl nanocrystals. The AuNP films deposited over glass led to enhanced-OSL emission, whereas the AuNP films deposited on aluminum substrates quenched the OSL emission. The enhanced-OSL intensity is proportional to the optical density of the film's plasmon resonance band at the stimulation wavelength. For the case of the AuNP/aluminum films, the luminescence quenching diminishes, and OSL intensity partially recovers upon increasing the distance between the AuNPs and the aluminum substrates, and between the luminescent nanocrystals and the AuNP films. These results suggest that plasmonic interactions between the emitter nanocrystals, the localized surface plasmons (LSP) of the AuNPs, and the substrate are responsible for the OSL enhancement and quenching. In this sense, the substrate dictates whether LSP relaxation occurs by radiative or non-radiative transisitions, leading to enhanced or quenched OSL, respectively. Therefore, besides showing that AuNP films can enhance and/or tune the sensitivity of luminescent radiation detectors, and demonstrating OSL as a new technique to investigate mechanisms of plasmon-enhanced luminescence, these results bring insights on how substrates strongly modify the optical properties of AuNP films. (paper)

  14. Luminescence dating of Netherland's sediments

    NARCIS (Netherlands)

    Wallinga, J.; Davids, F.; Dijkmans, J.W.A.

    2007-01-01

    Over the last decades luminescence dating techniques have been developed that allow earth scientists to determine the time of deposition of sediments. In this contribution we revity: 1) the development of the methodology, 2) tests of the reliability of luminescence dating on Netherlands' sediments;

  15. Discuss on luminescence dose data analysis technology

    International Nuclear Information System (INIS)

    Ma Xinhua; Xiao Wuyun; Ai Xianyun; Shi Zhilan; Liu Ying

    2009-01-01

    This article describes the development of luminescence dose data measurement and processing technology. General design planning of luminescence dose data measurement and processing technology is put forward with the diverse demands. The emphasis is focused on dose data processing method, luminescence curve analysis method, using of network, mechanics of communication among computers, data base management system of individual dose in this paper. The main methods and skills used in this technology as well as their advantages are also discussed. And it offers general design references for development luminescence dose data processing software. (authors)

  16. Luminescence enhancement of uranyl ion by benzoic acid in acetonitrile

    International Nuclear Information System (INIS)

    Satendra Kumar; Maji, S.; Joseph, M.; Sankaran, K.

    2014-01-01

    Uranyl ion is known for its characteristic green luminescence and therefore luminescence spectroscopy is a suitable technique for characterizing different uranyl species. In aqueous medium, luminescence of uranyl ion is generally weak due to its quenching by water molecules and therefore in order to enhance the luminescence of uranyl ion in aqueous medium, luminescence enhancing reagents such as H 3 PO 4 , H 2 SO 4 , HCIO 4 have been widely used. The other method to enhance the uranyl luminescence is by ligand sensitized luminescence, a method well established for lanthanides. In this work, luminescence of uranyl ion is found to be enhanced by benzoic acid in acetonitrile medium. In aqueous medium benzoic acid does not enhance the uranyl luminescence although it forms 1:1 and 1:2 complexes with uranyl ion. Luminescence spectra of uranyl benzoate revealed that enhancement is due to sensitization of uranyl luminescence by benzoate ions. UV-Vis spectroscopy has been utilized to characterize the specie formed in the in acetonitrile medium. UV-Vis spectroscopy along with luminescence spectra revealed that the specie to be tribenzoate complex of uranyl (UO 2 (C 6 H 5 COO) 3 ) - having D 3 h symmetry. (author)

  17. Recent developments in luminescent solar concentrators

    Science.gov (United States)

    van Sark, W. G. J. H. M.

    2014-10-01

    High efficiency photovoltaic devices combine full solar spectrum absorption and effective generation and collection of charge carriers, while commercial success depends on cost effectiveness in manufacturing. Spectrum modification using down shifting has been demonstrated in luminescent solar concentrators (LSCs) since the 1970s, as a cheap alternative for standard c-Si technology. LSCs consist of a highly transparent plastic plate, in which luminescent species are dispersed, which absorb incident light and emit light at a red-shifted wavelength, with high quantum efficiency. Material issues have hampered efficiency improvements, in particular re-absorption of light emitted by luminescent species and stability of these species. In this contribution, approaches are reviewed on minimizing re-absorption, which should allow surpassing the 10% luminescent solar concentrator efficiency barrier.

  18. Review of present trends in luminescence research

    International Nuclear Information System (INIS)

    Williams, F.; Delaware Univ., Newark

    1981-01-01

    The difficulties of a comprehensive review of the broad and diverse branches of molecular and solid-state luminescence research are noted. This review is thus limited to selective topics. Some general concepts and trends are then introduced, including: luminescence excitation as a collective excitation of a many-body problem, encompassing in some cases the source and probe in its formulation; continuing trends towards extremal conditions of experiments and towards inhomogeneous and structured materials, from man-made superlattices to biological materials; and increased attention to applications of luminescence research to lamps, displays, solar devices and biological research. Representative recent and new specific research areas include: site selection spectroscopy and 'hole burning'; picosecond delayed coherent anti-Stokes Raman scattering; computer simulation of dynamical processes in luminescence; electron-hole expansion from the Fermi pressure of e-h plasmas; and hot electron phenomena and hot luminescence. Finally some pending problems in luminescence research, such as reconciling the configuration coordinate model and the electronic band theory and clarifying multi-phonon non-radiative processes, are discussed. (orig.)

  19. Luminescence imaging of water during alpha particle irradiation

    Science.gov (United States)

    Yamamoto, Seiichi; Komori, Masataka; Koyama, Shuji; Toshito, Toshiyuki

    2016-05-01

    The luminescence imaging of water using the alpha particle irradiation of several MeV energy range is thought to be impossible because this alpha particle energy is far below the Cerenkov-light threshold and the secondary electrons produced in this energy range do not emit Cerenkov-light. Contrary to this consensus, we found that the luminescence imaging of water was possible with 5.5 MeV alpha particle irradiation. We placed a 2 MBq of 241Am alpha source in water, and luminescence images of the source were conducted with a high-sensitivity, cooled charge-coupled device (CCD) camera. We also carried out such imaging of the alpha source in three different conditions to compare the photon productions with that of water, in air, with a plastic scintillator, and an acrylic plate. The luminescence imaging of water was observed from 10 to 20 s acquisition, and the intensity was linearly increased with time. The intensity of the luminescence with the alpha irradiation of water was 0.05% of that with the plastic scintillator, 4% with air, and 15% with the acrylic plate. The resolution of the luminescence image of water was better than 0.25 mm FWHM. Alpha particles of 5.5 MeV energy emit luminescence in water. Although the intensity of the luminescence was smaller than that in air, it was clearly observable. The luminescence of water with alpha particles would be a new method for alpha particle detection and distribution measurements in water.

  20. Luminescence imaging of water during alpha particle irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Yamamoto, Seiichi, E-mail: s-yama@met.nagoya-u.ac.jp [Radiological and Medical Laboratory Sciences, Nagoya University Graduate School of Medicine (Japan); Komori, Masataka; Koyama, Shuji [Radiological and Medical Laboratory Sciences, Nagoya University Graduate School of Medicine (Japan); Toshito, Toshiyuki [Department of Proton Therapy Physics, Nagoya Proton Therapy Center, Nagoya City West Medical Center (Japan)

    2016-05-21

    The luminescence imaging of water using the alpha particle irradiation of several MeV energy range is thought to be impossible because this alpha particle energy is far below the Cerenkov-light threshold and the secondary electrons produced in this energy range do not emit Cerenkov-light. Contrary to this consensus, we found that the luminescence imaging of water was possible with 5.5 MeV alpha particle irradiation. We placed a 2 MBq of {sup 241}Am alpha source in water, and luminescence images of the source were conducted with a high-sensitivity, cooled charge-coupled device (CCD) camera. We also carried out such imaging of the alpha source in three different conditions to compare the photon productions with that of water, in air, with a plastic scintillator, and an acrylic plate. The luminescence imaging of water was observed from 10 to 20 s acquisition, and the intensity was linearly increased with time. The intensity of the luminescence with the alpha irradiation of water was 0.05% of that with the plastic scintillator, 4% with air, and 15% with the acrylic plate. The resolution of the luminescence image of water was better than 0.25 mm FWHM. Alpha particles of 5.5 MeV energy emit luminescence in water. Although the intensity of the luminescence was smaller than that in air, it was clearly observable. The luminescence of water with alpha particles would be a new method for alpha particle detection and distribution measurements in water.

  1. Towards Luminescence Dating Of Mosaic Glass

    Science.gov (United States)

    Galli, A.; Martini, M.; Sibila, E.; Villa, I.

    The possibility of dating archaeological glass by means of luminescent techniques has been investigated in recent years, despite the difficulties of this application, mainly linked to the amorphous structure of the material. We focused in particular on mosaic glass, after the encouraging results obtained on byzantine and medieval samples. Further studies were devoted to the comprehension of the luminescent mechanisms in silica glasses, and to the investigation of the relationships between luminescence, colouring or opacifier ions and crystalline phase of the vitreous matrix. The results of a study on the dosimetric characteristics of thermoluminescence (TL) and Optically Stimulated Luminescence (OSL) of a few medieval blue-green mosaic glasses from the San Lorenzo church (Milan) are presented, and the experimental protocols established to identify their suitability for dating are discussed.

  2. Luminescent amine sensor based on europium(III) chelate.

    Science.gov (United States)

    Petrochenkova, Nataliya V; Mirochnik, Anatolii G; Emelina, Tatyana B; Sergeev, Alexander A; Leonov, Andrei A; Voznesenskii, Sergey S

    2018-07-05

    The effect of methylamine vapor on luminescence of Eu(III) tris-benzoylacetonate (I) immobilized in thin-layer chromatography plates has been investigated. It has been revealed that interaction of I with analyte vapor results in increase of the intensity of Eu(III) luminescence. The mechanism of the effect of methylamine vapors on intensification of the Eu(III) luminescence has been suggested using the data of IR spectroscopy and quantum chemistry calculations. The mechanism of luminescence sensitization consists in bonding of an analyte molecule with a water molecule into the coordination sphere of Eu(III). As a result, the bond of a water molecule with the luminescence centre weakens, rigid structural fragment including europium ion, water and methylamine molecules forms. The presence of such fragment must naturally promote decrease of influence of OH-vibrations on luminescence of the complex I. Copyright © 2018 Elsevier B.V. All rights reserved.

  3. Silica nanoparticles with a substrate switchable luminescence

    International Nuclear Information System (INIS)

    Bochkova, O D; Mustafina, A R; Fedorenko, S V; Konovalov, A I

    2011-01-01

    Silica nanoparticles with visible (Tb and Ru doped), near IR (Yb doped) and dual visible-near IR luminescence (Ru-Yb doped) were obtained by reverse w/o microemulsion procedure. Plenty of luminescent complexes (from 4900 to 10000) encapsulated into each nanoparticle ensures the intensive luminescence of nanoparticles and their applicability as biomarkers. The silica surface decoration by definite anchor groups is the required step for the gaining to these nanoparticles marking and sensing functions. Thus covalent and non-covalent surface modification of these nanoparticles was developed to provide the binding with biotargets and sensing of anions. The dicationic surfactant coating of negatively charged Tb(III)-TCAS doped silica nanoparticles was chosen as the basis for the anion responsible system. The reversible insertion of the quenching anions (namely phenol red) into the surfactant based layer at the surface of luminescent nanoparticles switches off the Tb-centered luminescence. In turn the reversible reestablishment of the luminescence results from the competitive insertion of the non-quenching anions into the surfactant layer at the silica/water interface. The hydrophobic anions exemplified by dodecylsulfates versus hydrophilic ones (hydrophosphates) are preferable in the competition with phenol red anions.

  4. Quenching methods for background reduction in luminescence-based probe-target binding assays

    Energy Technology Data Exchange (ETDEWEB)

    Cai, Hong [Los Alamos, NM; Goodwin, Peter M [Los Alamos, NM; Keller, Richard A [Los Alamos, NM; Nolan, Rhiannon L [Santa Fe, NM

    2007-04-10

    Background luminescence is reduced from a solution containing unbound luminescent probes, each having a first molecule that attaches to a target molecule and having an attached luminescent moiety, and luminescent probe/target adducts. Quenching capture reagent molecules are formed that are capable of forming an adduct with the unbound luminescent probes and having an attached quencher material effective to quench luminescence of the luminescent moiety. The quencher material of the capture reagent molecules is added to a solution of the luminescent probe/target adducts and binds in a proximity to the luminescent moiety of the unbound luminescent probes to quench luminescence from the luminescent moiety when the luminescent moiety is exposed to exciting illumination. The quencher capture reagent does not bind to probe molecules that are bound to target molecules and the probe/target adduct emission is not quenched.

  5. Uranyl(VI) luminescence spectroscopy at elevated temperatures

    Energy Technology Data Exchange (ETDEWEB)

    Steudtner, Robin; Franzen, Carola; Brendler, Vinzenz [Helmholtz-Zentrum Dresden-Rossendorf e.V., Dresden (Germany). Div. Surface Processes; Haubitz, Toni [Brandenburg Univ. of Technology, Cottbus-Senftenberg (Germany)

    2016-07-01

    We studied the influence of temperature and ionic strength on the luminescence characteristics (band position, decay time and intensity) of the free uranyl ion (UO{sub 2}{sup 2+}) in acidic aqueous solution. Under the chosen conditions an increasing temperature reduced both intensity and luminescence decay time of the UO{sub 2}{sup 2+} luminescence, but the individual U(VI) emission bands did not change.

  6. Sub-ppb level detection of uranium using ligand sensitized luminescence

    International Nuclear Information System (INIS)

    Kumar, Satendra; Maji, S.; Joseph, M.; Sankaran, K.

    2015-01-01

    Uranyl ion (UO 2 2+ ) is known to exhibit weak luminescence in aqueous medium due to poor molar absorptivity and low quantum yield. In order to enhance the luminescence of uranyl ion in aqueous medium, luminescence enhancing reagents such as H 3 PO 4 , H 2 SO 4 , HClO 4 have been widely used. Like lanthanides, uranyl luminescence can also be sensitized by using some organic ligands. Pyridine 2,6-dicarboxylic acid (PDA) has shown enhancement of luminescence of uranyl in aqueous medium. Enhancement in intensity is due to sensitization of uranyl luminescence by PDA. In order to see the effect of non-aqueous medium, in this work, luminescence of uranyl-PDA complex has been studied in acetonitrile medium. More than one order luminescence enhancement has been observed compared to UO 2 2+ - PDA complex in aqueous medium. The lifetime of uranyl luminescence of the complex in acetonitrile medium is 90 μs which is very high compared to 10 μs in aqueous medium, suggesting that the luminescence enhancement is a result of reduction in non-radiative decay channels in acetonitrile medium. The large enhancement of uranyl luminescence of uranyl-PDA complex in acetonitrile medium can be used for ultra-trace level detection of uranium. Linearity in the luminescence intensity has been observed over the uranium concentration range of 5 to 80 ppb and the detection limit calculated using the criterion of 3 σ is ~ 0.2 ppb. (author)

  7. Optically stimulated exoelectron emission processes in quartz: comparison of experiment and theory

    DEFF Research Database (Denmark)

    Pagonis, V.; Ankjærgaard, Christina; Murray, A.S.

    2009-01-01

    Recent experiments have demonstrated that it is possible to measure optically stimulated exoelectron emission (OSE) signals simultaneously with optically stimulated luminescence (OSL) from quartz samples. These experiments provide valuable information on the charge movement in quartz grains. Two...... data yield a value of χ1.2 eV for the work function of quartz. The experimental temperature dependence of the OSE signals is interpreted on the basis of a photo-thermostimulated (PTSEE) process involving the main OSL trap at 320 °C; this process takes place with a thermal assistance energy estimated...... at W(0.29±0.02) eV. Good quantitative agreement is obtained between theory and experiment by assuming a thermal broadening of the thermal depletion factor for the OSL traps, described by a Gaussian distribution of energies....

  8. Apparatus for reducing solvent luminescence background emissions

    Energy Technology Data Exchange (ETDEWEB)

    Affleck, Rhett L. (Los Alamos, NM); Ambrose, W. Patrick (Los Alamos, NM); Demas, James N. (Charlottesville, VA); Goodwin, Peter M. (Jemez Springs, NM); Johnson, Mitchell E. (Pittsburgh, PA); Keller, Richard A. (Los Alamos, NM); Petty, Jeffrey T. (Los Alamos, NM); Schecker, Jay A. (Sante Fe, NM); Wu, Ming (Los Alamos, NM)

    1998-01-01

    The detectability of luminescent molecules in solution is enhanced by reducing the background luminescence due to impurity species also present in the solution. A light source that illuminates the solution acts to photolyze the impurities so that the impurities do not luminesce in the fluorescence band of the molecule of interest. Molecules of interest may be carried through the photolysis region in the solution or may be introduced into the solution after the photolysis region.

  9. Optically stimulated luminescence (OSL) and some other luminescence images from granite slices exposed with radiations

    International Nuclear Information System (INIS)

    Hashimoto, T.; Notoya, S.; Ojima, T.; Hoteida, M.

    1995-01-01

    Optically stimulated luminescence (OSL) images of some X- and γ-irradiated granite slices were obtained using photon detection through a 570 nm bandpass filter with diode-laser excitation of 910 nm. Alternative photo-induced phosphorescence (PIP) images, which were colour photographed immediately after the sunlight exposure of slice samples, were also found to be helpful in the observation of the luminescence properties and to filter selection for OSL measurements. These OSL and PIP images were compared with some other colour luminescence images, including thermoluminescence images (TLCI) and after-glow images (AGCI). It was obvious that there exists a variety of coloured emissions derived mainly from feldspar constituents and these were found to be dependent on the geological history or metamorphism of the granites. (Author)

  10. Defect studies in quartz: Composite nature of the blue and UV emissions

    Energy Technology Data Exchange (ETDEWEB)

    Martini, Marco, E-mail: m.martini@unimib.it [Dipartimento di Scienza dei Materiali, Università degli Studi di Milano Bicocca, via R. Cozzi 55, I-20125 Milano (Italy); INFN, Sezione di Milano Bicocca, Piazza della Scienza 1, I-20126 Milano (Italy); Fasoli, Mauro; Villa, Irene [Dipartimento di Scienza dei Materiali, Università degli Studi di Milano Bicocca, via R. Cozzi 55, I-20125 Milano (Italy)

    2014-05-01

    Quartz is an extremely diffused natural luminescence dosimeter. Thanks to the presence of traps and luminescence centres, its TSL and OSL (Thermally and Optically Stimulated Luminescence) properties have been extensively exploited. Quartz is then used for archaeological and geological dating and is one of the most useful materials for accident dosimetry. Many luminescence emissions are known to be present in the OSL and TSL of quartz. Three main emission bands are always reported, as the red, blue and UV bands, centred at around 650, 470, and 360–380 nm, respectively. Although the assignment of the luminescence emissions to specific defect centres in quartz is still undefined, a thorough analysis of the radioluminescence emissions and their response to irradiation and thermal treatments turned out to be very useful in understanding many features. Specifically, the presence of the same emission bands in natural and synthetic quartz and their dependence on the presence of extrinsic impurities is a common characteristic. The main impurities involve Al ions substituting Si ones and charge compensated by nearby either alkali ions, H{sup +}, or a hole. The emission spectra dynamics evidenced in our experiment confirm the role of Al-related centres in the luminescence properties of quartz. From the measurements presented in this paper the composite nature of the “blue” emission is confirmed. Two bands labelled as A at 2.5 eV and B at 2.8 eV contribute to the emission in this region, their behaviour being different as a function of irradiation. More complex is the picture in the UV region, where, besides the already detected C and D bands at 3.4 eV and 3.9 eV, respectively, two further emissions have been detected at 3.1 eV and 3.7 eV. Despite both the 3.4 eV and the 3.7 eV bands are shown to be affected by thermal treatments, the annealing temperature dependence of their intensity is markedly different. In fact, whereas the C band intensity, at 3.4 eV, increases

  11. Defect studies in quartz: Composite nature of the blue and UV emissions

    International Nuclear Information System (INIS)

    Martini, Marco; Fasoli, Mauro; Villa, Irene

    2014-01-01

    Quartz is an extremely diffused natural luminescence dosimeter. Thanks to the presence of traps and luminescence centres, its TSL and OSL (Thermally and Optically Stimulated Luminescence) properties have been extensively exploited. Quartz is then used for archaeological and geological dating and is one of the most useful materials for accident dosimetry. Many luminescence emissions are known to be present in the OSL and TSL of quartz. Three main emission bands are always reported, as the red, blue and UV bands, centred at around 650, 470, and 360–380 nm, respectively. Although the assignment of the luminescence emissions to specific defect centres in quartz is still undefined, a thorough analysis of the radioluminescence emissions and their response to irradiation and thermal treatments turned out to be very useful in understanding many features. Specifically, the presence of the same emission bands in natural and synthetic quartz and their dependence on the presence of extrinsic impurities is a common characteristic. The main impurities involve Al ions substituting Si ones and charge compensated by nearby either alkali ions, H + , or a hole. The emission spectra dynamics evidenced in our experiment confirm the role of Al-related centres in the luminescence properties of quartz. From the measurements presented in this paper the composite nature of the “blue” emission is confirmed. Two bands labelled as A at 2.5 eV and B at 2.8 eV contribute to the emission in this region, their behaviour being different as a function of irradiation. More complex is the picture in the UV region, where, besides the already detected C and D bands at 3.4 eV and 3.9 eV, respectively, two further emissions have been detected at 3.1 eV and 3.7 eV. Despite both the 3.4 eV and the 3.7 eV bands are shown to be affected by thermal treatments, the annealing temperature dependence of their intensity is markedly different. In fact, whereas the C band intensity, at 3.4 eV, increases after

  12. Modern luminescence spectroscopy of minerals and materials

    CERN Document Server

    Gaft, Michael; Panczer, Gerard

    2005-01-01

    Luminescence Spectroscopy of Minerals and Materials presents an overview of the general concepts in luminescence spectroscopy as well as experimental methods and their interpretation. Special emphasis is laid on the fluorescence lifetime and the determination of time-resolved spectra. This method enables the exposure of new luminescence in minerals previously hidden by more intensive centers. Specialists in the fields of solid state physics, chemistry and spectroscopy will find a wealth of new information in this unique book.

  13. Luminescence enhancement in irradiated polyethylene

    International Nuclear Information System (INIS)

    Charlesby, A.; Owen, G.P.

    1976-01-01

    Results are presented for the luminescence decay in polyethylene following irradiation at liquid nitrogen temperature and its enhancement on application of an electric field. It is found that both the luminescence enhancement and its subsequent decay may be described by a model involving electron tunnelling from a monoenergetic trap distribution to the parent positive ion. The possible nature of the trap is briefly discussed. (author)

  14. Photoluminescence, reddish orange long persistent luminescence and photostimulated luminescence properties of praseodymium doped CdGeO3 phosphor

    International Nuclear Information System (INIS)

    Jin, Yahong; Hu, Yihua; Chen, Li; Fu, Yinrong; Mu, Zhongfei; Wang, Tao; Lin, Jun

    2014-01-01

    Highlights: • A novel phosphor CdGeO 3 :Pr 3+ was synthesized successfully. • The persistent luminescence properties of CdGeO 3 :Pr 3+ were studied. • The photostimulated luminescence properties of CdGeO 3 :Pr 3+ were investigated. • The persistent and photostimulated luminescence mechanisms were discussed in detail. - Abstract: Praseodymium doped CdGeO 3 phosphors were prepared successfully by a conventional high temperature solid-state reaction method. It showed reddish orange long persistent luminescence (LPL) after the short UV-irradiation. The reddish orange photostimulated luminescence (PSL) was also observed upon near infrared stimulation at 980 nm after per-exposure into UV light. The origin of LPL and PSL was identified with the emission from Pr 3+ ions with the aid of traps in host lattice. The optimal concentration of Pr 3+ ions for the brightest photoluminescence (PL) emission and the best LPL characteristic were experimentally to be about 3% and 0.5 mol%, respectively. The trapping and de-trapping processes of charge carriers between shallower and deep traps were illustrated. A model was proposed on the basis of experimental results to study the mechanisms of LPL and PSL

  15. Cleavage Luminescence from Cleaved Indium Phosphide

    International Nuclear Information System (INIS)

    Dong-Guang, Li

    2008-01-01

    We outline the experiments performed to gain further information about the structure and properties of cleaved InP surfaces. The experiments involved detecting the luminescence produced after cleaving thin InP plates within a high vacuum, by a process of converting the luminescence to an electrical signal which could be amplified and measured accurately. The experimental results show that the detected luminescence durations from cleaved InP are usually only about 10μs. It is believed that this time represents the time of travel of the crack with the actual recombination time being much shorter. Strong signals could also be picked up from cleaved InP in air

  16. Luminescent converter of neodymium laser radiation

    International Nuclear Information System (INIS)

    Ryba-Romanowski, W.; Golab, S.

    1992-01-01

    The new luminescent converter of neodymium laser radiation has been worked out. Activated inorganic compounds of ytterbium and erbium ions has been used as luminescent agent. The multi-component inorganic glass containing tellurium oxide as well as boron, sodium, magnesium and zinc oxides has been applied as a converter matrix

  17. Luminescence spectroscopy with synchrotron radiation: History, highlights, future

    International Nuclear Information System (INIS)

    Zimmerer, Georg

    2006-01-01

    Luminescence spectroscopy and the investigation of dynamical processes with synchrotron radiation (SR) started about 35 years ago in nearly all SR laboratories existing at that time. In the present paper, the pioneering experiments are particularly emphasized. The exciting development is illustrated presenting highlights for the whole period from the beginning to the present day. The highlights are taken from fields like exciton self-trapping, inelastic electron-electron scattering, optically stimulated desorption, cross luminescence, or probing of cluster properties with luminescence spectroscopic methods. More technological aspects play a role in present day's experiments, like quantum cutting in rare-earth-doped insulators. Promising two-photon excitation and light amplification experiments with SR will be included, as well as the first results obtained in a luminescence experiment with selective Vaccum ultraviolet-free electron laser excitation. Finally, a few ideas concerning the future development of luminescence spectroscopy with SR will be sketched

  18. Chemisorptive luminescence on γ-irradiated magnesium oxide

    International Nuclear Information System (INIS)

    Breakspere, R.J.; Read, R.L.

    1976-01-01

    The intensity of a chemisorptive luminescence produced on MgO by oxygen at room temperature is increased by prior γ-irradiation of the MgO, under vacuum, before adsorption. This enhancement of the luminescence increases with radiation dose up to 1.9 x 10 6 rad and is attributed to the interaction between the F + sub (s) centres produced by the radiation and oxygen molecules arriving at the surface from the gas phase. In this work, the spectrum of the emitted luminescence could not be measured. (author)

  19. Europium enabled luminescent nanoparticles for biomedical applications

    Energy Technology Data Exchange (ETDEWEB)

    Syamchand, S.S., E-mail: syamchand.ss@gmail.com; Sony, G., E-mail: emailtosony@gmail.com

    2015-09-15

    Lanthanide based nanoparticles are receiving great attention ought to their excellent luminescent and magnetic properties and find challenging biomedical applications. Among the luminescent lanthanide NPs, europium based NPs (Eu-NPs) are better candidates for immunoassay and imaging applications. The Eu-NPs have an edge over quantum dots (QDs) by means of their stable luminescence, long fluorescence lifetime, sharp emission peaks with narrow band width, lack of blinking and biocompatibility. This review surveys the synthesis and properties of a variety of Eu-NPs consolidated from different research articles, for their applications in medicine and biology. The exquisite luminescent properties of Eu-NPs are explored for developing biomedical applications such as immunoassay and bioimaging including multimodal imaging. The biomedical applications of Eu-NPs are mostly diagnostic in nature and mainly focus on various key analytes present in biological systems. The luminescent properties of europium enabled NPs are influenced by a number of factors such as the site symmetry, the metal nanoparticles, metal ions, quantum dots, surfactants, morphology of Eu-NPs, crystal defect, phenomena like antenna effect and physical parameters like temperature. Through this review we explore and assimilate all the factors which affect the luminescence in Eu-NPs and coil a new thread of parameters that control the luminescence in Eu-NPs, which would provide further insight in developing Eu-based nanoprobes for future biomedical prospects. - Highlights: • The review describes 14 major factors that influence the luminescence properties of europium enabled luminescent nanoparticles (Eu-NPs). • Surveys different types of europium containing nanoparticles that have been reported for their biomedical applications. • Eu-NPs are conveniently divided into four different categories, based on the type of the substrates involved. The four categories are (1) virgin Eu-substrate based NPs; (2

  20. Europium enabled luminescent nanoparticles for biomedical applications

    International Nuclear Information System (INIS)

    Syamchand, S.S.; Sony, G.

    2015-01-01

    Lanthanide based nanoparticles are receiving great attention ought to their excellent luminescent and magnetic properties and find challenging biomedical applications. Among the luminescent lanthanide NPs, europium based NPs (Eu-NPs) are better candidates for immunoassay and imaging applications. The Eu-NPs have an edge over quantum dots (QDs) by means of their stable luminescence, long fluorescence lifetime, sharp emission peaks with narrow band width, lack of blinking and biocompatibility. This review surveys the synthesis and properties of a variety of Eu-NPs consolidated from different research articles, for their applications in medicine and biology. The exquisite luminescent properties of Eu-NPs are explored for developing biomedical applications such as immunoassay and bioimaging including multimodal imaging. The biomedical applications of Eu-NPs are mostly diagnostic in nature and mainly focus on various key analytes present in biological systems. The luminescent properties of europium enabled NPs are influenced by a number of factors such as the site symmetry, the metal nanoparticles, metal ions, quantum dots, surfactants, morphology of Eu-NPs, crystal defect, phenomena like antenna effect and physical parameters like temperature. Through this review we explore and assimilate all the factors which affect the luminescence in Eu-NPs and coil a new thread of parameters that control the luminescence in Eu-NPs, which would provide further insight in developing Eu-based nanoprobes for future biomedical prospects. - Highlights: • The review describes 14 major factors that influence the luminescence properties of europium enabled luminescent nanoparticles (Eu-NPs). • Surveys different types of europium containing nanoparticles that have been reported for their biomedical applications. • Eu-NPs are conveniently divided into four different categories, based on the type of the substrates involved. The four categories are (1) virgin Eu-substrate based NPs; (2

  1. luminescence properties

    Indian Academy of Sciences (India)

    1Faculty of Science and Arts, Department of Chemistry, Bozok University, Yozgat 66900, Turkey. 2Faculty of Science, Department of Chemistry, Erciyes ... synthesized by the conventional solid-state reaction method, their crystal structures and luminescence properties were investigated. X-ray diffraction patterns (XRD) ...

  2. Luminescent properties of fluorophosphate glasses with lead chalcogenides molecular clusters

    International Nuclear Information System (INIS)

    Kolobkova, E.V.; Kukushkin, D.S.; Nikonorov, N.V.; Shakhverdov, T.A.; Sidorov, A.I.; Vasiliev, V.N.

    2015-01-01

    Fluorophosphate glasses containing lead, selenium, and sulfur exhibit an intense luminescence in the 400–620 nm spectral region when excited by the 240–420 nm radiation. This luminescence is due to the presence of (PbSe) n and/or (PbS) n molecular clusters in the glasses, which appear in the as-prepared glasses before quantum dots formation. The thermal treatment at temperatures less than the glass transition temperature results in the red-shift of the luminescence bands and in an increase in the luminescence intensity. Heating the thermally treated glass samples leads to the reversible thermal quenching of the luminescence. - Highlights: • Fluorophosphate glasses with Pb, Se, and S ions contain (PbSe) n or (PbS) n molecular clusters. • (PbSe) n and (PbS) n molecular clusters possess luminescence in the visible with UV excitation. • Heating the glass leads to the reversible thermal quenching of the luminescence

  3. Luminescent polymethyl methacrylate modified by gamma radiation

    International Nuclear Information System (INIS)

    Morais, Guilherme F.; Forster, Pedro L.; Marchini, Leonardo G.; Lugao, Ademar B.; Parra, Duclerc F.

    2011-01-01

    Thin films of PMMA (polymethyl methacrylate) doped with luminescent complexes have been studied and developed for applications in advanced technologies. The problem of stability of these films is focused in this study. Films stabilization by reaction with fluorinated monomers is a recent study that aims to increase its luminescence properties for long time. The films were prepared by dilution of PMMA in chloroform with addition of europium complex, at proportion of 5% by weight of polymer. The luminescent polymer films were obtained by casting. Thin layer slides of the film were separated in three parts. One was reacted with fluorinated monomers (C 2 F 4 ) in closed reactor for 48 hours. A second part was reacted with C 2 F 4 after irradiation in gamma source at 5 kGy in simultaneous process. The last part was used as obtained. The luminescent polymer matrices were characterized using the techniques of infrared (FTIR) and thermogravimetry (TGA/DTG). Samples of the films were, in presence of fluorine monomers, exposed to ionizing radiation in dose of 5 kGy, for react with monomers in the doped polymer surface. In this case the effects of radiation were evaluated on the luminescent films. (author)

  4. Zero-reabsorption doped-nanocrystal luminescent solar concentrators.

    Science.gov (United States)

    Erickson, Christian S; Bradshaw, Liam R; McDowall, Stephen; Gilbertson, John D; Gamelin, Daniel R; Patrick, David L

    2014-04-22

    Optical concentration can lower the cost of solar energy conversion by reducing photovoltaic cell area and increasing photovoltaic efficiency. Luminescent solar concentrators offer an attractive approach to combined spectral and spatial concentration of both specular and diffuse light without tracking, but they have been plagued by luminophore self-absorption losses when employed on practical size scales. Here, we introduce doped semiconductor nanocrystals as a new class of phosphors for use in luminescent solar concentrators. In proof-of-concept experiments, visibly transparent, ultraviolet-selective luminescent solar concentrators have been prepared using colloidal Mn(2+)-doped ZnSe nanocrystals that show no luminescence reabsorption. Optical quantum efficiencies of 37% are measured, yielding a maximum projected energy concentration of ∼6× and flux gain for a-Si photovoltaics of 15.6 in the large-area limit, for the first time bounded not by luminophore self-absorption but by the transparency of the waveguide itself. Future directions in the use of colloidal doped nanocrystals as robust, processable spectrum-shifting phosphors for luminescent solar concentration on the large scales required for practical application of this technology are discussed.

  5. Oxide/polymer nanocomposites as new luminescent materials

    Science.gov (United States)

    Vollath, D.; Szabó, D. V.; Schlabach, S.

    2004-06-01

    It is demonstrated that nanocomposites, consisting of an electrically insulating oxide core and PMMA coating exhibit strong luminescence. This luminescence is connected to the interface, where PMMA is bond via a carboxylate bonding to the surface. In this case, luminescence is originated at the carbonyl group of the coating polymer. With decreasing particle size, this emission shows a blue shift, following a law inversely the ones found for quantum confinement systems. For semi-conducting oxides, such as ZnO, this interface related emission is found additionally to quantum confinement phenomena.

  6. Application of luminescence techniques in retrospective dosimetry

    DEFF Research Database (Denmark)

    Bøtter-Jensen, L.; Jungner, H.

    1999-01-01

    Luminescence signals measured from minerals within bricks or ceramic samples can provide information about the absorbed radiation dose. This feature has for several years been used in dating archaeological and geological samples and recently luminescence techniques have been intensively used far ...

  7. Luminescence at the end of the tunnelling - Investigating charge transfer mechanisms and luminescence dating methods for feldspar minerals

    NARCIS (Netherlands)

    Kars, R.H.

    2014-01-01

    This thesis comprises analyses of mineral physics with an application in geology and archeology. The thesis contributes to the development of feldspar luminescence dating methods in order to extend the applicable age range of feldspar luminescence dating in the Quaternary (last 2.6 Ma). The research

  8. Luminescence and the light emitting diode the basics and technology of leds and the luminescence properties of the materials

    CERN Document Server

    Williams, E W; Pamplin, BR

    2013-01-01

    Luminescence and the Light Emitting Diode: The Basics and Technology of LEDS and the Luminescence Properties of the Materials focuses on the basic physics and technology of light emitting diodes (LEDS) and pn junction lasers as well as their luminescence properties. Optical processes in semiconductors and the useful devices which can be made are discussed. Comprised of 10 chapters, this book begins with an introduction to the crystal structure and growth, as well as the optical and electrical properties of LED materials. The detailed fabrication of the LED is then considered, along with the lu

  9. Ratiometric Time-Gated Luminescence Probe for Nitric Oxide Based on an Apoferritin-Assembled Lanthanide Complex-Rhodamine Luminescence Resonance Energy Transfer System.

    Science.gov (United States)

    Tian, Lu; Dai, Zhichao; Liu, Xiangli; Song, Bo; Ye, Zhiqiang; Yuan, Jingli

    2015-11-03

    Using apoferritin (AFt) as a carrier, a novel ratiometric luminescence probe based on luminescence resonance energy transfer (LRET) between a Tb(3+) complex (PTTA-Tb(3+)) and a rhodamine derivative (Rh-NO), PTTA-Tb(3+)@AFt-Rh-NO, has been designed and prepared for the specific recognition and time-gated luminescence detection of nitric oxide (NO) in living samples. In this LRET probe, PTTA-Tb(3+) encapsulated in the core of AFt is the energy donor, and Rh-NO, a NO-responsive rhodamine derivative, bound on the surface of AFt is the energy acceptor. The probe only emits strong Tb(3+) luminescence because the emission of rhodamine is switched off in the absence of NO. Upon reaction with NO, accompanied by the turn-on of rhodamine emission, the LRET from Tb(3+) complex to rhodamine occurs, which results in the remarkable increase and decrease of the long-lived emissions of rhodamine and PTTA-Tb(3+), respectively. After the reaction, the intensity ratio of rhodamine emission to Tb(3+) emission, I565/I539, is ∼24.5-fold increased, and the dose-dependent enhancement of I565/I539 shows a good linearity in a wide concentration range of NO. This unique luminescence response allowed PTTA-Tb(3+)@AFt-Rh-NO to be conveniently used as a ratiometric probe for the time-gated luminescence detection of NO with I565/I539 as a signal. Taking advantages of high specificity and sensitivity of the probe as well as its good water-solubility, biocompatibility, and cell membrane permeability, PTTA-Tb(3+)@AFt-Rh-NO was successfully used for the luminescent imaging of NO in living cells and Daphnia magna. The results demonstrated the efficacy of the probe and highlighted it's advantages for the ratiometric time-gated luminescence bioimaging application.

  10. Novel Mechano-Luminescent Sensors Based on Piezoelectric/Electroluminescent Composites

    Directory of Open Access Journals (Sweden)

    Yunzhang Fang

    2011-04-01

    Full Text Available A high-sensitivity mechano-luminescent sensor was fabricated on the basis of piezoelectric/electroluminescent composites. The working principle of this mechano-luminescent sensor was elucidated by analyzing the relationship between the piezoelectric-induced charges and the electroluminescent effects. When a stress is applied on the piezoelectric layer, electrical charges will be induced at both the top and bottom sides of the piezoelectric layer. The induced electrical charges will lead to a light output from the electroluminescent layer, thus producing a mechano-luminescence effect. By increasing the vibration strength or frequency applied, the mechano-luminescence output can be obviously enhanced. Mechano-luminescence sensors have potential in smart stress-to-light devices, such as foot-stress-distribution-diagnosis systems and dynamic-load-monitors for bridge hanging cables.

  11. Increasing lanthanide luminescence by use of the RETEL effect.

    Science.gov (United States)

    Leif, Robert C; Vallarino, Lidia M; Becker, Margie C; Yang, Sean

    2006-08-01

    Luminescent lanthanide complexes produce emissions with the narrowest-known width at half maximum; however, their significant use in cytometry required an increase in luminescence intensity. The companion review, Leif et al., Cytometry 2006;69A:767-778, described a new technique for the enhancement of lanthanide luminescence, the Resonance Energy Transfer Enhanced Luminescence (RETEL) effect, which increases luminescence and is compatible with standard slide microscopy. The luminescence of the europium ion macrocyclic complex, EuMac, was increased by employing the RETEL effect. After adding the nonluminescent gadolinium ion complex of the thenoyltrifluoroacetonate (TTFA) ligand or the sodium salt of TTFA in ethanol solution, the EuMac-labeled sample was allowed to dry. Both a conventional arc lamp and a time-gated UV LED served as light sources for microscopic imaging. The emission intensity was measured with a CCD camera. Multiple time-gated images were summed with special software to permit analysis and effective presentation of the final image. With the RETEL effect, the luminescence of the EuMac-streptavidin conjugate increased at least six-fold upon drying. Nuclei of apoptotic cells were stained with DAPI and tailed with 5BrdUrd to which a EuMac-anti-5BrdU conjugate was subsequently attached. Time-gated images showed the long-lived EuMac luminescence but did not show the short-lived DAPI fluorescence. Imaging of DNA-synthesizing cells with an arc lamp showed that both S phase and apoptotic cells were labeled, and that their labeling patterns were different. The images of the luminescent EuMac and fluorescent DAPI were combined to produce a color image on a white background. This combination of simple chemistry, instrumentation, and presentation should make possible the inexpensive use of the lanthanide macrocycles, Quantum Dyes, as molecular diagnostics for cytological and histopathological microscopic imaging. (c) 2006 International Society for Analytical

  12. Luminescent solar concentrator

    Directory of Open Access Journals (Sweden)

    Tugce Tosun

    2015-07-01

    Full Text Available Luminescent solar concentrator (LSC is a device that has luminescent molecules embedding or topping polymeric or glass waveguide to generate electricity from sunlight with a photovoltaic cell attachment. LSCs can be employed both in small and large scale projects, independent on the direction or angle of the surface with respect to the sun, promising more freedom for integration in urban environments compared to the traditional PV systems. The aim of the SEB&C PDEng project is to investigate the applicability of this innovative technology in the built environment and to bridge the gap of knowledge linking societal, design and technological aspects. The final goal is to exhibit potential application concepts of LSC developed by co-creative methods at SPARK campus which is a hub for open innovation in built environment. Necessity of a paradigm shift towards sustainable and smart cities came into being due to the significant increase in energy demand of the buildings. The challenge is to increase renewable sources in the energy mix while designing aesthetic environments. Thus, building integrated renewable energy technologies represent a great opportunity to help overcome this current challenge. Smart energy, energy efficiency and use of renewable sources are key aspects to be considered nowadays and many innovative technologies need further exploitation to be commercially viable, such as luminescent solar concentrator.

  13. Luminescence and circularly polarized luminescence of macrocyclic Eu(III) and Tb(III) complexes embedded in xerogel and sol-gel SiO2 glasses

    International Nuclear Information System (INIS)

    Morita, M.; Rau, D.; Kai, T.

    2002-01-01

    Luminescence, time-resolved luminescence, circularly polarized luminescence (CPL) and decay profiles of Ln(III)(15-crownether-5) (Ln=Ce, Sm, Eu, Tb) and Tb(III)-(R),(S)-cyclen derivative complexes doped in xerogel and sol-gel silica glasses are measured at temperatures down to 10 K to characterize luminescence properties and the electronic structure in the excited states. Luminescence spectral profiles and calculation of crystal field parameters (B 0 (2) ,B 2 (2) ) in the 5 D 0 → 7 F J (J=1,2) transition give evidence of the fact that the pentagonal and planar structure of Eu(III) (15-crownether-5) does hold in xerogel and sol-gel glasses prepared at temperatures below 100 deg. C. As annealing temperatures are increased from 80 deg. C to 750 deg. C, Eu(III) complexes in sol-gel glasses are found to decompose gradually to SiO 2 :Eu 3+ . Tb(III)-(R) and (S)-cyclen derivative complexes in xerogel reveal at room temperature and 10 K sharp CPL spectra with luminescence dissymmetry factors g lum =-0.1 and 0.1, respectively. These complexes doped in sol-gel glasses represent luminescence characteristics of rare earth ions encapsulated in the nano-porous host

  14. Polymethylmethacrylate-based luminescent solar concentrators with bottom-mounted solar cells

    International Nuclear Information System (INIS)

    Zhang, Yi; Sun, Song; Kang, Rui; Zhang, Jun; Zhang, Ningning; Yan, Wenhao; Xie, Wei; Ding, Jianjun; Bao, Jun; Gao, Chen

    2015-01-01

    Graphical abstract: - Highlights: • Bottom-mounted luminescent solar concentrators on dye-doped plates were studied. • The mechanism of transport process was proposed. • The fabricated luminescent solar concentrator achieved a gain of 1.38. • Power conversion efficiency of 5.03% was obtained with cell area coverage of 27%. • The lowest cost per watt of $1.89 was optimized with cell area coverage of 18%. - Abstract: Luminescent solar concentrators offer an attractive approach to concentrate sunlight economically without tracking, but the narrow absorption band of luminescent materials hinders their further development. This paper describes bottom-mounted luminescent solar concentrators on dye-doped polymethylmethacrylate plates that absorb not only the waveguided light but also the transmitted sunlight and partial fluorescent light in the escape cone. A series of bottom-mounted luminescent solar concentrators with size of 78 mm × 78 mm × 7 mm were fabricated and their gain and power conversion efficiency were investigated. The transport process of the waveguided light and the relationship between the bottom-mounted cells were studied to optimize the performance of the device. The bottom-mounted luminescent solar concentrator with cell area coverage of 9% displayed a cell gain of 1.38, to our best knowledge, which is the highest value for dye-doped polymethylmethacrylate plate luminescent solar concentrators. Power conversion efficiency as high as 5.03% was obtained with cell area coverage of 27%. Furthermore, the bottom-mounted luminescent solar concentrator was found to have a lowest cost per watt of $1.89 with cell area coverage of 18%. These results suggested that the fabricated bottom-mounted luminescent solar concentrator may have a potential in low-cost building integrated photovoltaic application

  15. Kinetics of infrared stimulated luminescence from feldspars

    DEFF Research Database (Denmark)

    Jain, Mayank; Sohbati, Reza; Guralnik, Benny

    2015-01-01

    thermal and optical, of the infrared stimulated luminescence signal from feldspar. Based on the application of this model, it is concluded that different infra-red stimulated luminescence emissions (UV, blue, yellow and far-red) follow the same kinetics, and, therefore, involve participation of the same...

  16. Effect on thermoluminescence parameters of biotite mineral due to thermal quenching

    International Nuclear Information System (INIS)

    Kalita, J.M.; Wary, G.

    2012-01-01

    The Thermally Stimulated Luminescence (TSL) at room temperature X-ray irradiated natural biotite in form of micro-grain powder was studied under various heating rates. TSL peaks showed at temperatures 393 K, 399.6 K, 403.5 K, 404.5 K, 406.9 K at their respective heating rates 2 K/s, 4 K/s, 6 K/s, 8 K/s and 10 K/s. The effect of thermal quenching on thermoluminescence parameters such as peak maximum temperature, peak area, FWHM, geometrical symmetry factor, the activation energy were investigated. From the symmetry factor it is clear that the TL glow curve follows the first order kinetics for the lowest heating rate, but as the heating rate increases it defers from the first order. The activation energies for each heating rates were calculated by using Chen peak shape methods for general order kinetics and found to be decreased for higher heating rates. When activation energy is calculated by variable heating rate method it is observed that the method overestimated the value of activation energy and pre-exponential frequency factor significantly due to thermal quenching. - Highlights: ► Biotite is a common mineral with chemical formula K(Mg,Fe) 3 AlSi 3 O 10 (F,OH) 2 . ► Structural, compositional and elemental analysis of biotite is carried out. ► TSL of X-ray irradiated natural biotite was studied under various heating rates. ► The effect of thermal quenching on TL parameters has been investigated.

  17. Process for obtaining luminescent glass layers

    International Nuclear Information System (INIS)

    Heindi, R.; Robert, A.

    1984-01-01

    Process for obtaining luminescent glass layers, application to the production of devices provided with said layers and to the construction of photoscintillators. The process comprises projecting onto a support, by cathodic sputtering, the material of at least one target, each target including silica and at least one chemical compound able to give luminescent centers, such as a cerium oxide, so as to form at least one luminescent glass layer of the said support. The layer or layers formed preferably undergo a heat treatment such as annealing in order to increase the luminous efficiency thereof. It is in this way possible to form a scintillating glass layer on the previously frosted entrance window of a photomultiplier in order to obtain an integrated photoscintillator

  18. NaCl samples for optical luminescence dosimetry

    International Nuclear Information System (INIS)

    Catli, S.

    2005-01-01

    Optically stimulated luminescence (OSL) have been used broadly for luminescence dosimetry and dating. In many cases, it has been pointed out that the decay of the OSL do not generally behave according to a simple exponential function. In this study the Infra-red stimulated luminescence (IRSL) intensity from NaCl samples were experimentally measured. The decay curves for this sample were fitted to some functions and it is in good agreement with the function y = α + b exp(-cx). The IRSL decay curves from NaCl using different β-doses have been obtained and investigated their dose response

  19. Luminescent polymethyl methacrylate modified by gamma radiation

    Energy Technology Data Exchange (ETDEWEB)

    Morais, Guilherme F. [Faculdade de Tecnologia de Sao Paulo (FATEC-ZL), Sao Paulo, SP (Brazil); Forster, Pedro L.; Marchini, Leonardo G.; Lugao, Ademar B.; Parra, Duclerc F., E-mail: dfparra@ipen.b [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)

    2011-07-01

    Thin films of PMMA (polymethyl methacrylate) doped with luminescent complexes have been studied and developed for applications in advanced technologies. The problem of stability of these films is focused in this study. Films stabilization by reaction with fluorinated monomers is a recent study that aims to increase its luminescence properties for long time. The films were prepared by dilution of PMMA in chloroform with addition of europium complex, at proportion of 5% by weight of polymer. The luminescent polymer films were obtained by casting. Thin layer slides of the film were separated in three parts. One was reacted with fluorinated monomers (C{sub 2}F{sub 4}) in closed reactor for 48 hours. A second part was reacted with C{sub 2}F{sub 4} after irradiation in gamma source at 5 kGy in simultaneous process. The last part was used as obtained. The luminescent polymer matrices were characterized using the techniques of infrared (FTIR) and thermogravimetry (TGA/DTG). Samples of the films were, in presence of fluorine monomers, exposed to ionizing radiation in dose of 5 kGy, for react with monomers in the doped polymer surface. In this case the effects of radiation were evaluated on the luminescent films. (author)

  20. On luminescence lifetimes in quartz

    International Nuclear Information System (INIS)

    Chithambo, M.L.; Galloway, R.B.

    2000-01-01

    In this paper we present results of investigations concerning the time dependence of luminescence emission relative to the time of stimulation in quartz. Measurements of time-resolved spectra were performed on a new versatile pulsed light emitting diode system using 525 nm stimulation, an 11 μs duration pulse, a repetition rate of 11 kHz and a 64 μs dynamic range. Effects on luminescence lifetime resulting from sample treatments such as optical stimulation, irradiation, and preheating, are reported

  1. Fabrication of luminescent porous silicon with stain etches and evidence that luminescence originates in amorphous layers

    Science.gov (United States)

    Fathauer, R. W.; George, T.; Ksendzov, A.; Lin, T. L.; Pike, W. T.; Vasquez, R. P.; Wu, Z.-C.

    1992-01-01

    Simple immersion of Si in stain etches of HF:HNO3:H2O or NaNO2 in aqueous HF was used to produce films exhibiting luminescence in the visible similar to that of anodically-etched porous Si. All of the luminescent samples consist of amorphous porous Si in at least the near surface region. No evidence was found for small crystalline regions within these amorphous layers.

  2. Novel lanthanide doped micro- and mesoporous solids. Characterization of ion-host-interactions, species distribution and luminescence properties using time-resolved luminescence spectroscopy

    International Nuclear Information System (INIS)

    Gessner, Andre

    2010-12-01

    In this work lanthanide-doped microporous zeolites, microporous-mesoporous hybrid materials and mesoporous silicates were investigated regarding their luminescence properties and the ion-host-interactions using time-resolved luminescence spectroscopy. Thereby, time-resolved emission spectra (TRES) provide information in the wavelength and time domain. For the analysis of the TRES a broad set of analytic methods was applied and thus a corresponding ''toolbox'' developed. Fitting of the luminescence decays was performed with a discrete number of exponentials and supported by luminescence decay times distributions. Time-resolved area normalized emission spectra (TRANES), an advancement of TRES, could be used for the determination of the number of emissive lanthanide species in porous materials for the first time. Calculation of the decay-associated spectra (DAS) allowed the correlation of spectral information with luminescence decay times and thus delivered the luminescence spectra of the different europium species. For europium(III) we could use in addition the time-dependent asymmetry ratio and spectral evolution of the 5 D 0 - 7 F 0 -transition with time to obtain further information about the distribution of the lanthanide ions in the host material. Luminescence decay times and spectra allowed conclusions on the number of OH-oscillators in and the symmetry of the first coordination sphere. For the microporous and microporous-mesoporous materials were found different lanthanide species, which were characterized by the above mentioned methods. These lanthanide species can be found on different positions in the host material. One position is located deep in the pore system. Here, lanthanide ions are hardly accessible for water and mainly coordinated by framework oxygens. This results in long luminescence decay times and distorted coordination spheres. The second position can be found near or on the outer surface or in the mesopores. Lanthanide ions located here, are

  3. Controlled fabrication of luminescent and magnetic nanocomposites

    Science.gov (United States)

    Ma, Yingxin; Zhong, Yucheng; Fan, Jing; Huang, Weiren

    2018-03-01

    Luminescent and magnetic multifunctional nanocomposite is in high demand and widely used in many scales, such as drug delivery, bioseparation, chemical/biosensors, and so on. Although lots of strategies have been successfully developed for the demand of multifunctional nanocomposites, it is not easy to prepare multifunctional nanocomposites by using a simple method, and satisfy all kinds of demands simultaneously. In this work, via a facile and versatile method, luminescent nanocrystals and magnetic nanoparticles were successfully synthesized through self-assembly under vigorous stirring and ultrasonic treatment. These multifunctional nanocomposites are not only water stable but also find wide application such as magnetic separation and concentration with a series of moderate speed, multicolor fluorescence at different emission wavelength, high efficiency of the excitation and emission, and so on. By changing different kinds of luminescent nanocrystals and controlling the amount of luminescent and magnetic nanoparticles, a train of multifunctional nanocomposites was successfully fabricated via a versatile and robust method.

  4. Luminescence imaging using radionuclides: a potential application in molecular imaging

    International Nuclear Information System (INIS)

    Park, Jeong Chan; Il An, Gwang; Park, Se-Il; Oh, Jungmin; Kim, Hong Joo; Su Ha, Yeong; Wang, Eun Kyung; Min Kim, Kyeong; Kim, Jung Young; Lee, Jaetae; Welch, Michael J.; Yoo, Jeongsoo

    2011-01-01

    Introduction: Nuclear and optical imaging are complementary in many aspects and there would be many advantages when optical imaging probes are prepared using radionuclides rather than classic fluorophores, and when nuclear and optical dual images are obtained using single imaging probe. Methods: The luminescence intensities of various radionuclides having different decay modes have been assayed using luminescence imaging and in vitro luminometer. Radioiodinated Herceptin was injected into a tumor-bearing mouse, and luminescence and microPET images were obtained. The plant dipped in [ 32 P]phosphate solution was scanned in luminescence mode. Radio-TLC plate was also imaged in the same imaging mode. Results: Radionuclides emitting high energy β + /β - particles showed higher luminescence signals. NIH3T6.7 tumors were detected in both optical and nuclear imaging. The uptake of [ 32 P]phosphate in plant was easily followed by luminescence imaging. Radio-TLC plate was visualized and radiochemical purity was quantified using luminescence imaging. Conclusion: Many radionuclides with high energetic β + or β - particles during decay were found to be imaged in luminescence mode due mainly to Cerenkov radiation. 'Cerenkov imaging' provides a new optical imaging platform and an invaluable bridge between optical and nuclear imaging. New optical imaging probes could be easily prepared using well-established radioiodination methods. Cerenkov imaging will have more applications in the research field of plant science and autoradiography.

  5. The analysis of time-resolved optically stimulated luminescence: I. Theoretical considerations

    International Nuclear Information System (INIS)

    Chithambo, M L

    2007-01-01

    This is the first of two linked papers on the analysis of time-resolved optically stimulated luminescence. This paper focusses on a theoretical basis of analytical methods and on methods for interpretation of time-resolved luminescence spectra and calculation of luminescence throughput. Using a comparative analysis of the principal features of time-resolved luminescence and relevant analogues from steady state optical stimulation, formulae for configuring a measurement system for optimum performance are presented. We also examine the possible use of stretched-exponential functions for analysis of time-resolved optically stimulated luminescence spectra

  6. Luminescence and radiocarbon dating of raised beach sediments, Bunger Hills, East Antarctica

    International Nuclear Information System (INIS)

    Augustinus, P.C.; Duller, G.A.T.

    2002-01-01

    Luminescence and radiocarbon dating of raised marine sediments from the Bunger Hills, East Antarctica, demonstrates that luminescence methods can be applied to such poorly bleached sediments as long as the luminescence behaviour of the sediments is understood. This is essential as the complete zeroing of the luminescence signal due to light exposure is required to allow an accurate age for the sediment accumulation. Unfortunately, independent checks on the luminescence ages are rare. In the present study, some independent age control is provided by AMS radiocarbon ages from shell obtained from and adjacent to the luminescence dated horizons, although the radiocarbon ages may suffer to some degree from variability in the marine reservoir effect. Application of the single aliquot luminescence technique to feldspar grains from the marine sediments demonstrated that the luminescence behaviour of the sediments was complex. For each sample, 18 replicate paleodose estimates were used to demonstrate whether the sediments were well bleached before deposition. Optically, well-bleached samples give younger luminescence ages, whilst poorly bleached samples often give excessively old ages compared to the associated radiocarbon-dated material. (author)

  7. Magnetic-luminescent spherical particles synthesized by ultrasonic spray pyrolysis

    International Nuclear Information System (INIS)

    Michel, Norma L; Hirata, Gustavo A; Flores, Dora L

    2015-01-01

    The combination of magnetic and luminescent properties in a single particle system, opens-up a wide range of potential applications in biotechnology and biomedicine. In this work, we performed the synthesis of magnetic-luminescent Gd 2 O 3 :Eu 3+ @Fe 2 O 3 particles by ultrasonic spray pyrolysis performed in a tubular furnace. In order to achieve the composite formation, commercial superparamagnetic Fe 3 O 4 nanoparticles were coated with a luminescent Eu 3+ -doped Gd 2 O 3 shell in a low-cost one-step process. The spray pyrolysis method yields deagglomerated spherical shape magneto/luminescent particles. The photoluminescence spectra under UV excitation (λ Exc = 265 nm) of the magnetic Gd 2 O 3 :Eu 3+ @Fe 2 O 3 compound showed the characteristic red emission of Eu 3+ (λ Em = 612 nm). This magneto/luminescent system will find applications in biomedicine and biotechnology. (paper)

  8. Quantitative analysis of time-resolved infrared stimulated luminescence in feldspars

    DEFF Research Database (Denmark)

    Pagonis, Vasilis; Ankjærgaard, Christina; Jain, Mayank

    2016-01-01

    Time-resolved infrared-stimulated luminescence (TR-IRSL) from feldspar samples is of importance in the field of luminescence dating, since it provides information on the luminescence mechanism in these materials. In this paper we present new analytical equations which can be used to analyze TR-IR...

  9. Luminescence Properties of Surface Radiation-Induced Defects in Lithium Fluoride

    Science.gov (United States)

    Voitovich, A. P.; Kalinov, V. S.; Martynovich, E. F.; Novikov, A. N.; Runets, L. P.; Stupak, A. P.

    2013-11-01

    Luminescence and luminescence excitation spectra are recorded for surface radiation-induced defects in lithium fluoride at temperatures of 77 and 293 K. The presence of three bands with relatively small intensity differences is a distinctive feature of the excitation spectrum. These bands are found to belong to the same type of defects. The positions of the peaks and the widths of the absorption and luminescence bands for these defects are determined. The luminescence decay time is measured. All the measured characteristics of these surface defects differ from those of previously known defects induced by radiation in the bulk of the crystals. It is found that the luminescence of surface defects in an ensemble of nanocrystals with different orientations is not polarized. The number of anion vacancies in the surface defects is estimated using the polarization measurements. It is shown that radiative scattering distorts the intensity ratios of the luminescence excitation bands located in different spectral regions.

  10. Exciton luminescence in CdxMn1-xTe compounds

    International Nuclear Information System (INIS)

    Caraman, M.; Gashin, P.; Metelitsa, Snejana; Nicorici, Valentina; Nicorici, A.

    2002-01-01

    The Cd x Mn 1-x Te (0.5 7 W/cm 2 . The luminescence spectra were observed at 78 K. The results of the study had shown that the presence of relatively narrow luminescence peaks localized in the region of the fundamental absorption edge is characteristic for these spectra and for the majority of the crystals a wide maximum in the long wavelength region is observed. The luminescence maxima with an accuracy of ∼ 5 meV correspond to the resonance energy of the excitons of the state with n=1 determined from the absorption spectra. Hence, these maxima can be considered as exciton luminescence stimulated either by the excitons of the state n=1 or bounded to the exciton ionization centers. From the analysis of the absorption and exciton luminescence spectra one can make a conclusion about the fact that the homogeneity extent of the crystals decreases from CdTe to the compounds with x= 0.8 - 0.7 and slightly increases at the x decrease to 0.5. The exciton luminescence lines in CdTe and Cd 0.99 Mn 0.01 Te crystals is shifting by 7 - 10 meV relatively to the lines of free excitons absorption. This fact is explained by the fact that in these crystals, probably, excitons bounding to the lattice inherited defects with the binding energy of 7 - 10 meV participate in the luminescence. In the long wavelength region a wide peak is observed on which the impurity lines are not displayed. In the luminescence spectra of CdTe with 0.1%. As crystals three maxima at 1.51 eV, 1.46 eV and 1.42 eV are revealed. For pure CdTe the maximum at 1.4 eV is also revealed. These maxima are explained by the luminescence through the recombination levels localized at 0.46 eV. (authors)

  11. Study of the liquid water luminescence induced by charged particles

    International Nuclear Information System (INIS)

    Rusu, Mircea; Stere, Oana; Haiduc, Maria; Caramete, Laurentiu

    2004-01-01

    Many observations suggested that liquid water (with impurities) could give a luminescence output when irradiated with charged particles. We investigate theoretical and practical possibility of detecting such luminescence. Preliminary results on this possibility are presented, and a layout of the device proposed for measuring luminescence is given. (authors)

  12. Ion irradiation effect of alumina and its luminescence

    Energy Technology Data Exchange (ETDEWEB)

    Aoki, Yasushi; Yamamoto, Shunya; Naramoto, Hiroshi [Japan Atomic Energy Research Inst., Takasaki, Gunma (Japan). Takasaki Radiation Chemistry Research Establishment; My, N T

    1997-03-01

    The luminescence spectra of single crystalline alpha-alumina and ruby which has 0.02% of Cr{sub 2}O{sub 3} as a impurity, induced by 200 keV He{sup +} and Ar{sup +} irradiation were measured at room temperature as a function of irradiation dose. The analysis of the measured spectra showed the existence of three main luminescence features in the wavelength region of 250 to 350 nm, namely anionic color centers, F-center at 411 nm and F{sup +}-center at 330 nm and a band observed around 315 nm. As alpha-alumina was irradiated with He{sup +}, F-center and F{sup +}-center luminescence grew and decayed, but the behaviors of those were different from each other. It seems that a concentration quenching occurred on the F-center luminescence in the dose range above 1x10{sup 14} He/cm{sup 2}. Furthermore, F-center luminescence was strongly suppressed in ruby, compared with that in alumina. On the other hand, the luminescence band around 315 nm appeared only in the early stage of irradiation and did not show its growth part. The dose dependent behavior was similar to that of Cr{sup 3+} emission at 695 nm (R-line) in ruby in both cases of He{sup +} and Ar{sup +} irradiation. Based on the experimental results mentioned above, the processes of defect formation and excitation in alumina in the early stage of ion irradiation will be discussed. (author)

  13. Flight testing of a luminescent surface pressure sensor

    Science.gov (United States)

    Mclachlan, B. G.; Bell, J. H.; Espina, J.; Gallery, J.; Gouterman, M.; Demandante, C. G. N.; Bjarke, L.

    1992-01-01

    NASA ARC has conducted flight tests of a new type of aerodynamic pressure sensor based on a luminescent surface coating. Flights were conducted at the NASA ARC-Dryden Flight Research Facility. The luminescent pressure sensor is based on a surface coating which, when illuminated with ultraviolet light, emits visible light with an intensity dependent on the local air pressure on the surface. This technique makes it possible to obtain pressure data over the entire surface of an aircraft, as opposed to conventional instrumentation, which can only make measurements at pre-selected points. The objective of the flight tests was to evaluate the effectiveness and practicality of a luminescent pressure sensor in the actual flight environment. A luminescent pressure sensor was installed on a fin, the Flight Test Fixture (FTF), that is attached to the underside of an F-104 aircraft. The response of one particular surface coating was evaluated at low supersonic Mach numbers (M = 1.0-1.6) in order to provide an initial estimate of the sensor's capabilities. This memo describes the test approach, the techniques used, and the pressure sensor's behavior under flight conditions. A direct comparison between data provided by the luminescent pressure sensor and that produced by conventional pressure instrumentation shows that the luminescent sensor can provide quantitative data under flight conditions. However, the test results also show that the sensor has a number of limitations which must be addressed if this technique is to prove useful in the flight environment.

  14. Recent Advances on Luminescent Enhancement-Based Porous Silicon Biosensors.

    Science.gov (United States)

    Jenie, S N Aisyiyah; Plush, Sally E; Voelcker, Nicolas H

    2016-10-01

    Luminescence-based detection paradigms have key advantages over other optical platforms such as absorbance, reflectance or interferometric based detection. However, autofluorescence, low quantum yield and lack of photostability of the fluorophore or emitting molecule are still performance-limiting factors. Recent research has shown the need for enhanced luminescence-based detection to overcome these drawbacks while at the same time improving the sensitivity, selectivity and reducing the detection limits of optical sensors and biosensors. Nanostructures have been reported to significantly improve the spectral properties of the emitting molecules. These structures offer unique electrical, optic and magnetic properties which may be used to tailor the surrounding electrical field of the emitter. Here, the main principles behind luminescence and luminescence enhancement-based detections are reviewed, with an emphasis on europium complexes as the emitting molecule. An overview of the optical porous silicon microcavity (pSiMC) as a biosensing platform and recent proof-of-concept examples on enhanced luminescence-based detection using pSiMCs are provided and discussed.

  15. X-ray luminescent glasses

    International Nuclear Information System (INIS)

    Takahashi, T.; Yamada, O.

    1981-01-01

    X-ray luminescent glasses comprising a divalent cation such as an alkaline earth metal or other divalent cations such as pb, cd, or zn, and certain rare earth metaphosphates are suitable as vitreous, x-ray phosphors or x-ray luminescent glass fibers in an x-ray intensifying screen. The glasses have the composition n(Mo X p2o5)((1-y)tb2o3 X yce2o3 X 3p2o5) wherein N is greater than zero but less than or equal to 16, M is an alkaline earth metal or other divalent cation such as pb, cd, or zn, and Y is greater than or equal to zero but less than one

  16. Determination of uranium by luminescent method (tablet variant)

    International Nuclear Information System (INIS)

    Sergeev, A.N.; Yufa, B.Ya.

    1985-01-01

    A new tablet variant of luminescent determination of uranium in rocks is developed. The analytical process includes the following operations: sample decomposition, uranium separation from luminescence quencher impurities, preparation of luminescent sample (tablet), photometry of the tablet. The method has two variants developed: the first one is characterized by a more hard decomposition, sample mass being 0.2 g; the second variant has a better detection limit (5x10 -6 %), the sample mass being 0.2-1 g. Procedures of the sample preparation for both variants of analysis are described

  17. Fabrication and Spectral Properties of Wood-Based Luminescent Nanocomposites

    Directory of Open Access Journals (Sweden)

    Xianjun Li

    2014-01-01

    Full Text Available Pressure impregnation pretreatment is a conventional method to fabricate wood-based nanocomposites. In this paper, the wood-based luminescent nanocomposites were fabricated with the method and its spectral properties were investigated. The results show that it is feasible to fabricate wood-based luminescent nanocomposites using microwave modified wood and nanophosphor powders. The luminescent strength is in positive correlation with the amount of phosphor powders dispersed in urea-formaldehyde resin. Phosphors absorb UV and blue light efficiently in the range of 400–470 nm and show a broad band of bluish-green emission centered at 500 nm, which makes them good candidates for potential blue-green luminescent materials.

  18. K2SO4 and LiKSO4 crystals luminescence

    International Nuclear Information System (INIS)

    Charapiev, B.; Nurakhmetov, T.N.

    2002-01-01

    In the paper a nature of X-ray and tunnel luminescence in LiKSO 4 and Li 2 SO 4 ·H 2 O crystals are discussed. It is shown, that X-ray luminescence and Li 2 SO 4 ·H 2 O and LiKSO 4 appeals in the result of electrons recombination with auto-localized holes (SO 4 - ), and tunnel luminescence appeals at electrons transfer from ground state of electron center into hole center capture ground state. Under heating of irradiated crystal de-localized holes at recombination moment with electron capture centers are forming auto-localized excitons, which are disintegrating with photon emitting, and so X-ray luminescence spectrum and thermally induces luminescence peaks are coinciding. Nature of radiation appealing in LiKSO 4 at ultraviolet excitation is discussing

  19. Time-resolved luminescence from quartz: An overview of contemporary developments and applications

    Energy Technology Data Exchange (ETDEWEB)

    Chithambo, M.L., E-mail: m.chithambo@ru.ac.za [Department of Physics and Electronics, Rhodes University, PO BOX 94, Grahamstown 6140 (South Africa); Ankjærgaard, C. [Soil Geography and Landscape Group, Wageningen University Netherlands Centre for Luminescence Dating, Droevendaalsesteeg 3, 6708 PB Wageningen, The Netherlands (Netherlands); Pagonis, V. [McDaniel College, Physics Department, Westminster, MD 21157 (United States)

    2016-01-15

    Time-resolved optical stimulation of luminescence has become established as a key method for measurement of optically stimulated luminescence from quartz, feldspar and α-Al{sub 2}O{sub 3}:C, all materials of interest in dosimetry. The aim of time-resolved optical stimulation is to separate in time the stimulation and emission of luminescence. The luminescence is stimulated from a sample using a brief light pulse and the emission monitored during stimulation in the presence of scattered stimulating light or after pulsing, over photomultiplier noise only. Although the use of the method in retrospective dosimetry has been somewhat limited, the technique has been successfully applied to study mechanisms in the processes leading up to luminescence emission. The main means for this has been the temperature dependence of the luminescence intensity as well as the luminescence lifetimes determined from time-resolved luminescence spectra. In this paper we review some key developments in theory and applications to quartz including methods of evaluating lifetimes, techniques of evaluating kinetic parameters using both the dependence of luminescence intensity and lifetime on measurement temperature, and of lifetimes on annealing temperature. We then provide an overview of some notable applications such as separation of quartz signals from a quartz–feldspar admixture and the utility of the dynamic throughput, a measure of luminescence measured as a function of the pulse width. The paper concludes with some suggestions of areas where further exploration would advance understanding of dynamics of luminescence in quartz and help address some outstanding problems in its application.

  20. Luminescence properties of some food dye-stuffs

    International Nuclear Information System (INIS)

    Astanov, S.Kh.; Muminova, Z.A.; Urunov, R.G.

    2004-01-01

    The luminescence properties of the natural food dye-stuffs and vitamins in temperature range of 300-5.2 K are studied. On the basis of experimental data on quantum yields of the fluorescence, trans-cis-isomerization and luminescence of the molecular oxygen the main ways of the inactivation of electronic excitations in researching compounds have been defined. (author)

  1. Method and apparatus for reducing solvent luminescence background emissions

    Energy Technology Data Exchange (ETDEWEB)

    Affleck, Rhett L. (Los Alamos, NM); Ambrose, W. Patrick (Los Alamos, NM); Demas, James N. (Charlottesville, VA); Goodwin, Peter M. (Jemez Springs, NM); Johnson, Mitchell E. (Pittsburgh, PA); Keller, Richard A. (Los Alamos, NM); Petty, Jeffrey T. (Los Alamos, NM); Schecker, Jay A. (Santa Fe, NM); Wu, Ming (Los Alamos, NM)

    1998-01-01

    The detectability of luminescent molecules in solution is enhanced by reducing the background luminescence due to impurity species also present in the solution. A light source that illuminates the solution acts to photolyze the impurities so that the impurities do not luminesce in the fluorescence band of the molecule of interest. Molecules of interest may be carried through the photolysis region in the solution or may be introduced into the solution after the photolysis region.

  2. Luminescent materials and their applications

    CERN Document Server

    Virk, Hardev Singh

    2015-01-01

    It is pertinent to note that Luminescence phenomenon has once again occupied a central stage with the announcement of Nobel Prize in October 2014 to three Japanese scientists. The discovery of Galium Nitride proved to be a revolutionary step forward in creation of Blue LEDs. With the advent of LED lamps we now have more long-lasting and more efficient alternatives to older light sources. The Volume under reference consists of 9 Chapters, written by experts in the area of Luminescent Materials. First 5 Chapters are contributed as Review Papers and the last 4 are based on Research Papers.Chapter

  3. Cerium luminescence in nd0 perovskites

    International Nuclear Information System (INIS)

    Setlur, A.A.; Happek, U.

    2010-01-01

    The luminescence of Ce 3+ in perovskite (ABO 3 ) hosts with nd 0 B-site cations, specifically Ca(Hf,Zr)O 3 and (La,Gd)ScO 3 , is investigated in this report. The energy position of the Ce 3+ excitation and emission bands in these perovskites is compared to those of typical Al 3+ perovskites; we find a Ce 3+ 5d 1 centroid shift and Stokes shift that are larger versus the corresponding values for the Al 3+ perovskites. It is also shown that Ce 3+ luminescence quenching is due to Ce 3+ photoionization. The comparison between these perovskites shows reasonable correlations between Ce 3+ luminescence quenching, the energy position of the Ce 3+ 5d 1 excited state with respect to the host conduction band, and the host composition. - Graphical abstract: Ce 3+ decay times versus temperature for perovskites with nd 0 B-site cations.

  4. Paper-based biodetection using luminescent nanoparticles.

    Science.gov (United States)

    Ju, Qiang; Noor, M Omair; Krull, Ulrich J

    2016-05-10

    Point-of-care and in-field technologies for rapid, sensitive and selective detection of molecular biomarkers have attracted much interest. Rugged bioassay technology capable of fast detection of markers for pathogens and genetic diseases would in particular impact the quality of health care in the developing world, but would also make possible more extensive screening in developed countries to tackle problems such as those associated with water and food quality, and tracking of infectious organisms in hospitals and clinics. Literature trends indicate an increasing interest in the use of nanomaterials, and in particular luminescent nanoparticles, for assay development. These materials may offer attributes for development of assays and sensors that could achieve improvements in analytical figures of merit, and provide practical advantages in sensitivity and stability. There is opportunity for cost-efficiency and technical simplicity by implementation of luminescent nanomaterials as the basis for transduction technology, when combined with the use of paper substrates, and the ubiquitous availability of cell phone cameras and associated infrastructure for optical detection and transmission of results. Luminescent nanoparticles have been described for a broad range of bioanalytical targets including small molecules, oligonucleotides, peptides, proteins, saccharides and whole cells (e.g., cancer diagnostics). The luminescent nanomaterials that are described herein for paper-based bioassays include metal nanoparticles, quantum dots and lanthanide-doped nanocrystals. These nanomaterials often have broad and strong absorption and narrow emission bands that improve opportunity for multiplexed analysis, and can be designed to provide emission at wavelengths that are efficiently processed by conventional digital cameras. Luminescent nanoparticles can be embedded in paper substrates that are designed to direct fluid flow, and the resulting combination of technologies can offer

  5. Luminescence properties of tetravalent uranium in aqueous solution

    International Nuclear Information System (INIS)

    Kirishima, A.; Kimura, T.; Nagaishi, R.; Tochiyama, O.

    2004-01-01

    The luminescence spectra of U 4+ in aqueous solutions were observed in the UV-VIS region at ambient and liquid nitrogen temperatures. The excitation spectrum indicates that the luminescence is arising from the deexcitation of a 5f electron at the 1 S 0 level and no other emissions of U 4+ in aqueous solutions were detected for other f-f transitions. All the luminescence peaks were assigned to the transitions from 1 S 0 to lower 5f levels. To estimate the luminescence lifetime, luminescence decay curves were measured using time-resolved laser-induced fluorescence spectroscopy. At room temperature, the decay curve indicated that the lifetime was shorter than 20 ns. On the other hand, the frozen sample of U 4+ in aqueous solution at liquid nitrogen temperature showed the same emission spectrum as at room temperature and its lifetime was 149 ns in H 2 O system and 198 ns in D 2 O system. The longer lifetime at liquid nitrogen temperature made it possible to measure the spectrum of U 4+ at the concentration as low as 10 -6 M. The difference in the anion species (ClO 4 - , Cl - , SO 4 2- ) affected the structure of the emission spectrum to some extent. (orig.)

  6. Nanostructured Ag-zeolite Composites as Luminescence-based Humidity Sensors

    Science.gov (United States)

    Dieu, Bjorn; Roeffaers, Maarten B.J.; Hofkens, Johan

    2016-01-01

    Small silver clusters confined inside zeolite matrices have recently emerged as a novel type of highly luminescent materials. Their emission has high external quantum efficiencies (EQE) and spans the whole visible spectrum. It has been recently reported that the UV excited luminescence of partially Li-exchanged sodium Linde type A zeolites [LTA(Na)] containing luminescent silver clusters can be controlled by adjusting the water content of the zeolite. These samples showed a dynamic change in their emission color from blue to green and yellow upon an increase of the hydration level of the zeolite, showing the great potential that these materials can have as luminescence-based humidity sensors at the macro and micro scale. Here, we describe the detailed procedure to fabricate a humidity sensor prototype using silver-exchanged zeolite composites. The sensor is produced by suspending the luminescent Ag-zeolites in an aqueous solution of polyethylenimine (PEI) to subsequently deposit a film of the material onto a quartz plate. The coated plate is subjected to several hydration/dehydration cycles to show the functionality of the sensing film. PMID:27911397

  7. [Synthesis of reserve polyhydroxyalkanoates by luminescent bacteria].

    Science.gov (United States)

    Boiandin, A N; Kalacheva, G S; Rodicheva, E K; Volova, T G

    2008-01-01

    The ability of marine luminescent bacteria to synthesize polyesters of hydroxycarboxylic acids (polyhydroxyalkanoates, PHA) as reserve macromolecules was studied. Twenty strains from the collection of the luminescent bacteria CCIBSO (WDSM839) of the Institute of Biophysics, Siberian Branch, Russian Academy of Sciences, assigned to different taxa (Photobacterium leiognathi, Ph. phosphoreum, Vibrio harveyi, and V. fischeri) were analyzed. The most productive strains were identified, and the conditions ensuring high polymer yields in batch culture (40-70% of the cell dry mass weight) were determined. The capacity of synthesizing two- and three-component polymers containing hydroxybutyric acid as the main monomer and hydroxyvaleric and hydroxyhexanoic acids was revealed in Ph. leiognathi and V. harveyi strains. The results allow luminescent microorganisms to be regarded as new producers of multicomponent polyhydroxyalkanoates.

  8. Reply to Comments on 'Effect of heating rate on kinetic parameters of β-irradiated Li2B4O7:Cu,Ag,P in TSL measurements'

    International Nuclear Information System (INIS)

    Ege, A; Tekin, E; Karali, T; Can, N; Prokić, M

    2009-01-01

    We appreciate the opportunity to respond to comments regarding the paper published by Ege et al (2007 Effect of heating rate on kinetic parameters of β-irradiated Li 2 B 4 O 7 :Cu,Ag,P in TSL measurements Meas. Sci. Technol. 18 889). We would like to thank the authors for taking the time to tell us about their opinion, but unfortunately we do not agree with them completely. In the article presented by Kumar and Chourasiya some comment is advanced to the analysis of the glow curves measured with different heating rates, presented in our recent study. According to our study, the area under the glow curve decreases with increasing heating rate in TL–temperature plots due to the quenching effects. Contrary to this, Kumar and Chourasiya suggest that this decrease is due to the normalization process. Here we hope to clarify any confusion regarding our published study. (reply)

  9. Influence of Nanosized Silicon Oxide on the Luminescent Properties of ZnO Nanoparticles

    Directory of Open Access Journals (Sweden)

    Vitaliy Shvalagin

    2016-01-01

    Full Text Available For practical use of nanosized zinc oxide as the phosphor its luminescence quantum yields should be maximized. The aim of this work was to enhance luminescent properties of ZnO nanoparticles and obtain high-luminescent ZnO/SiO2 composites using simpler approaches to colloidal synthesis. The luminescence intensity of zinc oxide nanoparticles was increased about 3 times by addition of silica nanocrystals to the source solutions during the synthesis of ZnO nanoparticles. Then the quantum yield of luminescence of the obtained ZnO/SiO2 composites is more than 30%. Such an impact of silica is suggested to be caused by the distribution of ZnO nanocrystals on the surface of silica, which reduces the probability of separation of photogenerated charges between the zinc oxide nanoparticles of different sizes, and as a consequence, there is a significant increase of the luminescence intensity of ZnO nanoparticles. This way of increasing nano-ZnO luminescence intensity facilitates its use in a variety of devices, including optical ultraviolet and visible screens, luminescent markers, antibacterial coatings, luminescent solar concentrators, luminescent inks for security printing, and food packaging with abilities of informing consumers about the quality and safety of the packaged product.

  10. On the correlation between annealing and variabilities in pulsed-luminescence from quartz

    International Nuclear Information System (INIS)

    Chithambo, M.L.

    2006-01-01

    Properties of luminescence lifetimes in quartz related to annealing between 500 and 900 deg. C have been investigated. The luminescence was pulse-stimulated at 470nm from sets of granular quartz annealed at 500, 600, 700, 800, and 900 deg. C. The lifetimes decrease with annealing temperature from about 42 to 33μs when the annealing temperature is increased from 500 to 900 deg. C. Luminescence lifetimes are most sensitive to duration of annealing at 600 deg. C, decreasing from 40.2+/-0.7μs by as much as 7μs when the duration of annealing is changed from 10 to 60min. However, at 800-900 deg. C lifetimes are essentially independent of annealing temperature at about 33μs. Increasing the exciting beta dose causes an increase in the lifetimes of the stimulated luminescence in the sample annealed at 800 deg. C but not in those annealed at either 500 or 600 deg. C. The temperature-resolved distribution of luminescence lifetimes is affected by thermal quenching of luminescence. These features may be accounted for with reference to two principal luminescence centres involved in the luminescence emission process

  11. Luminescence characteristics of dental ceramics for retrospective dosimetry: a preliminary study

    International Nuclear Information System (INIS)

    Bailiff, I.K.; Correcher, V.; Delgado, A.; Goksu, Y.; Huebner, S.

    2002-01-01

    Ceramic materials that are widely employed in dental prosthetics and repairs exhibit luminescent properties. Because of their use in the body, these materials are potentially of interest in situations where retrospective dosimetry for individuals is required but where monitoring was not planned. The luminescent properties of dental ceramics obtained in Germany, Spain and the UK were examined. Linear dose-response characteristics were obtained in the range <100 mGy to 10 Gy using thermoluminescence (TL), optically stimulated luminescence and infrared-stimulated luminescence measurement techniques. Measurements of time-resolved luminescence were also performed to examine the nature of the luminescence recombination under visible (470 nm) and IR (855 nm) stimulation. The results obtained by TL and optically stimulated techniques suggest that there may be deeper traps than previously observed in certain types of dental ceramic. Such traps may be less susceptible to optical and athermal fading than was reported in earlier studies. (author)

  12. Quantitative analysis of time-resolved infrared stimulated luminescence in feldspars

    Energy Technology Data Exchange (ETDEWEB)

    Pagonis, Vasilis, E-mail: vpagonis@mcdaniel.edu [McDaniel College, Physics Department, Westminster, MD 21157 (United States); Ankjærgaard, Christina [Soil Geography and Landscape Group & Netherlands Centre for Luminescence dating, Wageningen University, PO Box 47, 6700 AA Wageningen (Netherlands); Jain, Mayank [Center for Nuclear Technologies, Technical University of Denmark, DTU Risø Campus, Roskilde (Denmark); Chithambo, Makaiko L. [Department of Physics and Electronics, Rhodes University, PO BOX 94, Grahamstown 6140 (South Africa)

    2016-09-15

    Time-resolved infrared-stimulated luminescence (TR-IRSL) from feldspar samples is of importance in the field of luminescence dating, since it provides information on the luminescence mechanism in these materials. In this paper we present new analytical equations which can be used to analyze TR-IRSL signals, both during and after short infrared stimulation pulses. The equations are developed using a recently proposed kinetic model, which describes localized electronic recombination via tunneling between trapped electrons and recombination centers in luminescent materials. Recombination is assumed to take place from the excited state of the trapped electron to the nearest-neighbor center within a random distribution of luminescence recombination centers. Different possibilities are examined within the model, depending on the relative importance of electron de-excitation and recombination. The equations are applied to experimental TR-IRSL data of natural feldspars, and good agreement is found between experimental and modeling results.

  13. Luminescence dating at Rose cottage cave: a progress report

    CSIR Research Space (South Africa)

    Woodborne, S

    1997-10-01

    Full Text Available Deal with infrared-stimulated luminescence and thermoluminescence dates from Rose Cottage Cave in South Africa. Discrepancy between luminescence and radiocarbon dates; Concentration of radioactive elements in sediments before and after leaching...

  14. Luminescence basic concepts, applications and instrumentation

    CERN Document Server

    Virk, Hardev Singh

    2014-01-01

    The word luminescence was first used by a German physicist, Eilhardt Wiedemann, in 1888. He also classified luminescence into six kinds according to the method of excitation. No better basis of classification is available today. He recognized photoluminescence, thermoluminescence, electroluminescence, crystalloluminescence, triboluminescence, and chemiluminescence. The designations are obvious, characterized by the prefix. This Volume consists of 9 Chapters, including 8 Review Papers and one Case Study. The first two papers are based on OLEDs. Organic light emitting diodes (OLEDs) have been th

  15. Defect-Induced Luminescence of a Self-Activated Borophosphate Phosphor

    Science.gov (United States)

    Han, Bing; Liu, Beibei; Dai, Yazhou; Zhang, Jie

    2018-05-01

    A self-activated borophosphate phosphor Ba3BPO7 was prepared via typical solid-state reaction in thermal-carbon reduction atmosphere. The structural and luminescence properties were investigated using x-ray powder diffraction (XRD), Fourier transform infrared (FT-IR) spectroscopy, and photoluminescence spectroscopy. Upon excitation with ultraviolet (UV) light, the as-prepared phosphor shows bright greenish-yellow emission with a microsecond-level fluorescence lifetime, which could result from the oxygen vacancies produced in the process of solid-state synthesis. The possible luminescence mechanism is proposed. Through the introduction of defects in the host, this work realizes visible luminescence in a pure borophosphate compound that does not contain any rare earth or transition metal activators, so it is helpful to develop defect-related luminescent materials in view of energy conservation and environmental protection for sustainable development.

  16. Luminescent properties of terbium complex with phenylanthranilic acid

    International Nuclear Information System (INIS)

    Alakaeva, L.A.; Kalazhokova, I.A.; Naurzhanova, F.Kh.

    1990-01-01

    Existence of terbium luminescence reaction in complex with phenanthranilic acid (FAA) is ascertained. The optimal conditions of terbium complexing with FAA are found. The ratio of components in the complex is 1:1. The influence of foreign rare earth in terbium luminescence intensity in complex with FAA is studied

  17. Doped luminescent materials and particle discrimination using same

    Science.gov (United States)

    Doty, F. Patrick; Allendorf, Mark D; Feng, Patrick L

    2014-10-07

    Doped luminescent materials are provided for converting excited triplet states to radiative hybrid states. The doped materials may be used to conduct pulse shape discrimination (PSD) using luminescence generated by harvested excited triplet states. The doped materials may also be used to detect particles using spectral shape discrimination (SSD).

  18. Polarization memory of white luminescence of Ag nanoclusters dispersed in glass host.

    Science.gov (United States)

    Kuznetsov, A S; Tikhomirov, V K; Moshchalkov, V V

    2012-09-10

    A mechanism for white luminescence of Ag nanoclusters dispersed in oxyfluoride glass host has been revealed by studying a temperature dependence of its polarization memory. The spectral dependence of the polarization memory indicates the presence of a variety of Ag nanoclusters, particularly emitting in the blue, green and red. Temperature activated intercluster energy transfer has been found responsible for white luminescence. The means for increasing luminescence quantum yield have been suggested. This efficient white luminescence may be used in highly demanded devices, such as luminescent lamps, displays, color phosphors for LEDs, photovoltaic devices based on down shifting of solar spectrum.

  19. Principal and secondary luminescence lifetime components in annealed natural quartz

    International Nuclear Information System (INIS)

    Chithambo, M.L.; Ogundare, F.O.; Feathers, J.

    2008-01-01

    Time-resolved luminescence spectra from quartz can be separated into components with distinct principal and secondary lifetimes depending on certain combinations of annealing and measurement temperature. The influence of annealing on properties of the lifetimes related to irradiation dose and temperature of measurement has been investigated in sedimentary quartz annealed at various temperatures up to 900 deg. C. Time-resolved luminescence for use in the analysis was pulse stimulated from samples at 470 nm between 20 and 200 deg. C. Luminescence lifetimes decrease with measurement temperature due to increasing thermal effect on the associated luminescence with an activation energy of thermal quenching equal to 0.68±0.01eV for the secondary lifetime but only qualitatively so for the principal lifetime component. Concerning the influence of annealing temperature, luminescence lifetimes measured at 20 deg. C are constant at about 33μs for annealing temperatures up to 600 0 C but decrease to about 29μs when the annealing temperature is increased to 900 deg. C. In addition, it was found that lifetime components in samples annealed at 800 deg. C are independent of radiation dose in the range 85-1340 Gy investigated. The dependence of lifetimes on both the annealing temperature and magnitude of radiation dose is described as being due to the increasing importance of a particular recombination centre in the luminescence emission process as a result of dynamic hole transfer between non-radiative and radiative luminescence centres

  20. A luminescence imaging system based on a CCD camera

    DEFF Research Database (Denmark)

    Duller, G.A.T.; Bøtter-Jensen, L.; Markey, B.G.

    1997-01-01

    Stimulated luminescence arising from naturally occurring minerals is likely to be spatially heterogeneous. Standard luminescence detection systems are unable to resolve this variability. Several research groups have attempted to use imaging photon detectors, or image intensifiers linked...... to photographic systems, in order to obtain spatially resolved data. However, the former option is extremely expensive and it is difficult to obtain quantitative data from the latter. This paper describes the use of a CCD camera for imaging both thermoluminescence and optically stimulated luminescence. The system...

  1. Luminescent microporous metal–organic framework with functional Lewis basic sites on the pore surface: Quantifiable evaluation of luminescent sensing mechanisms towards Fe{sup 3+}

    Energy Technology Data Exchange (ETDEWEB)

    Jin, Jun-Cheng [Key Laboratory of Synthetic and Natural Functional Molecule Chemistry of the Ministry of Education, Shaanxi Key Laboratory of Physico-Inorganic Chemistry, College of Chemistry & Materials Science, Northwest University, Xi' an 710069 (China); Technology Promotion Center of Nano Composite Material of Biomimetic Sensor and Detecting Technology, Preparation and Application, Anhui Provincial Laboratory West Anhui University, Anhui 237012 (China); Guo, Rui-Li; Zhang, Wen-Yan [Key Laboratory of Synthetic and Natural Functional Molecule Chemistry of the Ministry of Education, Shaanxi Key Laboratory of Physico-Inorganic Chemistry, College of Chemistry & Materials Science, Northwest University, Xi' an 710069 (China); Jiang, Chen [Technology Promotion Center of Nano Composite Material of Biomimetic Sensor and Detecting Technology, Preparation and Application, Anhui Provincial Laboratory West Anhui University, Anhui 237012 (China); Wang, Yao-Yu, E-mail: wyaoyu@nwu.edu.cn [Key Laboratory of Synthetic and Natural Functional Molecule Chemistry of the Ministry of Education, Shaanxi Key Laboratory of Physico-Inorganic Chemistry, College of Chemistry & Materials Science, Northwest University, Xi' an 710069 (China)

    2016-11-15

    A systematic study has been conducted on a novel luminescent metal-organic framework, ([Zn(bpyp)(L-OH)]·DMF·2H{sub 2}O){sub n} (1), to explore its sensing mechanisms to Fe{sup 3+}. Structure analyses show that compound 1 exist pyridine N atoms and -OH groups on the pore surface for specific sensing of metal ions via Lewis acid-base interactions. On this consideration, the quenching mechanisms are studied and the processes are controlled by multiple mechanisms in which dynamic and static mechanisms are calculated, achieving the quantification evaluation of the quenching process. This work not only achieves the quantitative evaluation of the luminescence quenching but also provides certain insights into the quenching process, and the possible mechanisms explored in this work may inspire future research and design of target luminescent metal-organic frameworks (LMOFs) with specific functions. - Graphical abstract: A systematic study has been conducted on a novel luminescent metal-organic framework to explore its sensing mechanisms to Fe{sup 3+}. The quenching mechanisms are studied and the processes are controlled by multiple mechanisms in which dynamic and static mechanisms are calculated, achieving the quantification evaluation of the quenching process. - Highlights: • A novel porous luminescent MOF containing uncoordinated groups in interlayer channels was successfully synthesized. • The compound 1 can exhibit significant luminescent sensitivity to Fe{sup 3+}, which make its good candidate as luminescent sensor. • The corresponding dynamic and static quenching constants are calculated, achieving the quantification evaluation of the quenching process.

  2. Methods of producing luminescent images

    International Nuclear Information System (INIS)

    Broadhead, P.; Newman, G.A.

    1977-01-01

    A method is described for producing a luminescent image in a layer of a binding material in which is dispersed a thermoluminescent material. The layer is heated uniformly to a temperature of 80 to 300 0 C and is exposed to luminescence inducing radiation whilst so heated. The preferred exposing radiation is X-rays and preferably the thermoluminescent material is insensitive to electromagnetic radiation of wavelength longer than 300 mm. Information concerning preparation of the luminescent material is given in BP 1,347,672; this material has the advantage that at elevated temperatures it shows increased sensitivity compared with room temperature. At temperatures in the range 80 to 150 0 C the thermoluminescent material exhibits 'afterglow', allowing the image to persist for several seconds after the X-radiation has ceased, thus allowing the image to be retained for visual inspection in this temperature range. At higher temperatures, however, there is negligible 'afterglow'. The thermoluminescent layers so produced are particularly useful as fluoroscopic screens. The preferred method of heating the thermoluminescent material is described in BP 1,354,149. An example is given of the application of the method. (U.K.)

  3. Spatially-resolved measurement of optically stimulated luminescence and time-resolved luminescence

    International Nuclear Information System (INIS)

    Bailiff, I.K.; Mikhailik, V.B.

    2003-01-01

    Spatially-resolved measurements of optically stimulated luminescence (OSL) were performed using a two-dimensional scanning system designed for use with planar samples. The scanning system employs a focused laser beam to stimulate a selected area of the sample, which is moved under the beam by a motorised stage. Exposure of the sample is controlled by an electronic shutter. Mapping of the distribution of OSL using a continuous wave laser source was obtained with sub-millimeter resolution for samples of sliced brick, synthetic single crystal quartz, concrete and dental ceramic. These revealed sporadic emission in the case of brick or concrete and significant spatial variation of emission for quartz and dental ceramic slices. Determinations of absorbed dose were performed for quartz grains within a slice of modern brick. Reconfiguration of the scanner with a pulsed laser source enabled quartz and feldspathic minerals within a ceramic sample to be thinner region. about 6 nm from the extrapolation of themeasuring the time-resolved luminescence spectrum

  4. Luminescence centers in bismuth orthogermanate

    International Nuclear Information System (INIS)

    Bordun, O.M.

    2001-01-01

    The luminescence and photoexcitation spectra of single crystals,ceramics,and thin films of Bi 4 Ce 3 O 1 2 are studied.The decomposition of the luminescence spectra into elementary components by the Alentsev-Fock method showed that they consist of three bands with maxima at 2.7,2.4,and 2.05 eV.The bands with maxima at 2.7 and 2.4 eV are assigned to the emission of self-trapped Frenkel excitons describing the excited state of a (BiO 6 ) 9- molecular ion. Emission bands with maxima at 2.0 5 eV are assigned to recombination on traps caused by structural defects

  5. Quantitative analysis of time-resolved infrared stimulated luminescence in feldspars

    DEFF Research Database (Denmark)

    Pagonis, Vasilis; Ankjærgaard, Christina; Jain, Mayank

    2016-01-01

    Time-resolved infrared-stimulated luminescence (TR-IRSL) from feldspar samples is of importance in the field of luminescence dating, since it provides information on the luminescence mechanism in these materials. In this paper we present new analytical equations which can be used to analyze TR-IR....... The equations are applied to experimental TR-IRSL data of natural feldspars, and good agreement is found between experimental and modeling results....

  6. A Radiation Dosimetry Method Using Pulsed Optically Stimulated Luminescence

    International Nuclear Information System (INIS)

    Akselrod, M.S.; McKeever, S.W.S.

    1999-01-01

    A method for the determination of absorbed radiation dose is described based on pulsed optically stimulated luminescence (POSL). The method relies upon the stimulation of an irradiated sample with a train of light pulses from a suitable light source (e.g. a laser) using a wavelength which is within the range of wavelengths corresponding to the radiation-induced optical absorption in the irradiated sample. The subsequent emitted light, due to the detrapping of trapped charges and their subsequent recombination with charge of the opposite sign, is synchronously detected in the period between each stimulation pulse. The total luminescence is summed over the desired number of stimulation pulses and this forms the measured POSL signal. By monitoring the emitted light only in the period between stimulation pulses one can reduce the optical filtering required to discriminate between the stimulation light and the emission light; in this way a high measurement efficiency, and, therefore, a high radiation sensitivity (luminescence intensity per unit absorbed dose) is achieved. Key parameters in the method are the intrinsic luminescence lifetime for the material being used as the luminescent detector, the width of the optical stimulation pulse, and the period between pulses. For optimum operation the measurement parameters should be such that both the pulse width and the time between pulses are much less than the luminescence lifetime. By appropriate choice of the power of the optical stimulation, the frequency of the stimulation pulses, and the total stimulation period, one can also re-measure the absorbed dose several times. In this way, a re-read capability is available with the procedure. The method is illustrated using light from a 2nd-harmonic Nd:YAG laser, with irradiated, anion-deficient aluminium oxide as the luminescent detector material. (author)

  7. Luminescence from cavitation bubbles deformed in uniform pressure gradients

    Science.gov (United States)

    Supponen, Outi; Obreschkow, Danail; Kobel, Philippe; Farhat, Mohamed

    2017-09-01

    Presented here are observations that demonstrate how the deformation of millimetric cavitation bubbles by a uniform pressure gradient quenches single-collapse luminescence. Our innovative measurement system captures a broad luminescence spectrum (wavelength range, 300-900 nm) from the individual collapses of laser-induced bubbles in water. By varying the bubble size, driving pressure, and perceived gravity level aboard parabolic flights, we probed the limit from aspherical to highly spherical bubble collapses. Luminescence was detected for bubbles of maximum radii within the previously uncovered range, R0=1.5 -6 mm, for laser-induced bubbles. The relative luminescence energy was found to rapidly decrease as a function of the bubble asymmetry quantified by the anisotropy parameter ζ , which is the dimensionless equivalent of the Kelvin impulse. As established previously, ζ also dictates the characteristic parameters of bubble-driven microjets. The threshold of ζ beyond which no luminescence is observed in our experiment closely coincides with the threshold where the microjets visibly pierce the bubble and drive a vapor jet during the rebound. The individual fitted blackbody temperatures range between Tlum=7000 and Tlum=11 500 K but do not show any clear trend as a function of ζ . Time-resolved measurements using a high-speed photodetector disclose multiple luminescence events at each bubble collapse. The averaged full width at half-maximum of the pulse is found to scale with R0 and to range between 10 and 20 ns.

  8. Study on the relationship of protease production and luminescence in Vibrio harveyi.

    Science.gov (United States)

    Nakayama, T; Nomura, N; Matsumura, M

    2006-07-01

    To demonstrate that Vibrio harveyi produces various types of toxins and how the production of those toxins is related with luminescence. Luminescence and toxicity of eight V. harveyi were evaluated. We demonstrated that all V. harveyi emitting luminescence were isolated from marine organisms and also showed that they were highly pathogenic when compared with culture collection V. harveyi based on cytotoxic assay test. On the contrary, V. harveyi isolated from shrimp farm showed no luminescence but showed high pathogenicity based on toxicity test. The effect of protease inhibitors on pathogenicity and luminescence was also investigated. We demonstrated that light emission of pathogenic V. harveyi remarkably decreased after addition of protease inhibitor. Furthermore, extracellular proteins from cell-free culture supernatant of luminescent and nonluminescent V. harveyi were compared using SDS-PAGE analysis. Results showed that there were differences in molecular weight and amount of proteins. Vibrio harveyi parasiting marine organisms have both luminescence and pathogenicity. Based on this study, luminescence and protease toxin activity in V. harveyi are related. Moreover, this paper clarified that V. harveyi produces various types of toxins. The current study demonstrated that V. harveyi produces two kinds of toxins, haemolysin and protease toxin. It may be clear roots of V. harveyi toxin.

  9. f-state luminescence of lanthanide and actinide ions in solution

    International Nuclear Information System (INIS)

    Beitz, J.V.

    1993-01-01

    Detailed studies of the luminescence of aquated Am 3+ are presented in the context of prior lanthanide and actinide ion work. The luminescing state of aquated Am 3+ is confirmed to be 5 D l based on observed emission and excitation spectra. The luminescence lifetime of Am 3+ in H 2 O solution is (22 ± 3) ns and (155 ± 4) ns in D 2 O solution at 295 K. Judd-Ofelt transition intensity theory qualitatively describes the observed Am 3+ relative integrated fluorescence intensities. Recent luminescence studies on complexed trivalent f-element ions in solution are reviewed as to the similarities and differences between lanthanide ion 4f state and actinide ion 5f state properties

  10. Silica-modified luminescent LaPO4 :Eu@LaPO4 @SiO2 core/shell nanorods: Synthesis, structural and luminescent properties.

    Science.gov (United States)

    Ansari, Anees A

    2018-02-01

    Monoclinic-type tetragonal LaPO 4 :Eu (core) and LaPO 4 :Eu@LaPO 4 (core/shell) nanorods (NRs) were successfully prepared using a urea-based co-precipitation process under ambient conditions. An amorphous silica layer was coated around the luminescent core/shell NRs via the sol-gel process to improve their solubility and colloidal stability in aqueous and non-aqueous media. The prepared nano-products were systematically characterized by X-ray diffraction pattern, transmission electron microscopy, energy dispersive X-ray analysis, and FTIR, UV/Vis, and photoluminescence spectroscopy to examine their phase purity, crystal phase, surface chemistry, solubility and luminescence characteristics. The length and diameter of the nano-products were in the range 80-120 nm and 10-15 nm, respectively. High solubility of the silica-modified core/shell/Si NRs was found for the aqueous medium. The luminescent core NRs exhibited characteristic excitation and emission transitions in the visible region that were greatly affected by surface growth of insulating LaPO 4 and silica layers due to the multiphonon relaxation rate. Our luminescence spectral results clearly show a distinct difference in intensities for core, core/shell, and core/shell/Si NRs. Highly luminescent NRs with good solubility could be useful candidates for a variety of photonic-based biomedical applications. Copyright © 2017 John Wiley & Sons, Ltd.

  11. Holographic patterning of luminescent photopolymer nanocomposites

    International Nuclear Information System (INIS)

    Sakhno, Oksana V.; Smirnova, Tatiana N.; Goldenberg, Leonid M.; Stumpe, Joachim

    2008-01-01

    Volume phase gratings in the photopolymerisable composites, containing luminescent nanoparticles have been fabricated for the first time. Nanoparticles of LaPO 4 , doped by Ce 3+ and Tb 3+ ions (the trade name is REN-X-green) with high luminescence quantum yield were used as a luminescent inorganic additive. The holographic gratings in such materials are formed as a result of the diffusion distribution of the nanoparticles during exposure of photopolymerisable composites to interference pattern. The influence of the pre-polymer formulation and the holographic patterning parameters on the grating formation is comprehensively investigated. The use of the optimised pre-polymer syrup containing two monomers with sufficiently different polymerisation rates allows fabrication of gratings with diffraction efficiency up to 80% at low optical losses (< 5%) (20 μm film thickness). To obtain maximum diffraction efficiency the intensity and the period of the interference pattern were optimised for each formulation. In addition maximum diffraction efficiency was achieved with the nanocomposites containing 30-32 wt.% of nanoparticles. On the other hand the highest possible modulation of the nanoparticles' concentration was obtained for the concentration of about 20 wt.%. In this case maximum ordering of the nanoparticles in the polymer matrix is achieved. The photoluminescence of the nanoparticles within the homogeneous polymer film and within the grating has been measured. The example application of the photopolymerisable composite containing luminescence inorganic nanoparticles in holographic security technology has been demonstrated

  12. Thermal dependence of luminescence lifetimes and radioluminescence in quartz

    Energy Technology Data Exchange (ETDEWEB)

    Pagonis, V., E-mail: vpagonis@mcdaniel.edu [McDaniel College, Physics Department, Westminster, MD 21157 (United States); Chithambo, M.L. [Department of Physics and Electronics, Rhodes University, PO BOX 94, Grahamstown 6140 (South Africa); Chen, R. [Raymond and Beverly Sackler School of Physics and Astronomy, Tel-Aviv University, Tel-Aviv 69978 (Israel); Chruścińska, A. [Institute of Physics, Nicholas Copernicus University, 87-100 Toruń (Poland); Fasoli, M. [Department of Materials Science, University of Milano-Bicocca, Via Cozzi 53, 20125 Milano (Italy); Li, S.H. [Department of Earth Sciences, The University of Hong Kong (Hong Kong); Martini, M. [Department of Materials Science, University of Milano-Bicocca, Via Cozzi 53, 20125 Milano (Italy); Ramseyer, K. [Institut für Geologie, Baltzerstrasse 1-3, 3012 Bern (Switzerland)

    2014-01-15

    During time-resolved optical stimulation experiments (TR-OSL), one uses short light pulses to separate the stimulation and emission of luminescence in time. Experimental TR-OSL results show that the luminescence lifetime in quartz of sedimentary origin is independent of annealing temperature below 500 °C, but decreases monotonically thereafter. These results have been interpreted previously empirically on the basis of the existence of two separate luminescence centers L{sub H} and L{sub L} in quartz, each with its own distinct luminescence lifetime. Additional experimental evidence also supports the presence of a non-luminescent hole reservoir R, which plays a critical role in the predose effect in this material. This paper extends a recently published analytical model for thermal quenching in quartz, to include the two luminescence centers L{sub H} and L{sub L}, as well as the hole reservoir R. The new extended model involves localized electronic transitions between energy states within the two luminescence centers, and is described by a system of differential equations based on the Mott–Seitz mechanism of thermal quenching. It is shown that by using simplifying physical assumptions, one can obtain analytical solutions for the intensity of the light during a TR-OSL experiment carried out with previously annealed samples. These analytical expressions are found to be in good agreement with the numerical solutions of the equations. The results from the model are shown to be in quantitative agreement with published experimental data for commercially available quartz samples. Specifically the model describes the variation of the luminescence lifetimes with (a) annealing temperatures between room temperature and 900 °C, and (b) with stimulation temperatures between 20 and 200 °C. This paper also reports new radioluminescence (RL) measurements carried out using the same commercially available quartz samples. Gaussian deconvolution of the RL emission spectra was

  13. Phosphorescence quantum yield determination with time-gated fluorimeter and Tb(III)-acetylacetonate as luminescence reference

    Energy Technology Data Exchange (ETDEWEB)

    Penzkofer, A., E-mail: alfons.penzkofer@physik.uni-regensburg.de [Fakultät für Physik, Universität Regensburg, Universitätsstrasse 31, D-93053 Regensburg (Germany)

    2013-03-29

    Highlights: ► Procedure for absolute phosphorescence quantum yield measurement is described. ► Experimental setup for absolute luminescence quantum yield standard calibration. ► Tb(acac){sub 3} proposed as phosphorescence quantum yield reference standard. ► Luminescence quantum yield of Tb(acac){sub 3} in cyclohexane measured. ► Luminescence lifetime of Tb(acac){sub 3} in cyclohexane measured. - Abstract: Phosphorescence quantum yield measurements of fluorescent and phosphorescent samples require the use of time-gated fluorimeters in order to discriminate against the fluorescence contribution. As reference standard a non-fluorescent luminescent compound is needed for absolute phosphorescence quantum yield determination. For this purpose the luminescence behavior of the rare earth chelate terbium(III)-acetylacetonate (Tb(acac){sub 3}) was studied (determination of luminescence quantum yield and luminescence lifetime). The luminescence quantum yield of Tb(acac){sub 3} was determined by using an external light source and operating the fluorimeter in chemo/bioluminescence mode with a fluorescent dye (rhodamine 6G in methanol) as reference standard. A procedure is developed for absolute luminescence (phosphorescence) quantum yield determination of samples under investigation with a time-gated fluorimeter using a non-fluorescent luminescent compound of known luminescence quantum yield and luminescence lifetime.

  14. Terbium and dysprosium complexes luminescence at low temperatures

    Energy Technology Data Exchange (ETDEWEB)

    Meshkova, S B; Kravchenko, T B; Kononenko, L.I.; Poluehktov, N S [AN Ukrainskoj SSR, Odessa. Fiziko-Khimicheskij Inst.

    1979-01-01

    The variation is studied of the luminescence intensity of terbium and dysprosium complexes used in the analysis as solutions are cooled down to the liquid nitrogen temperature. Three groups of methods have been studied: observation of fluorescence of aqueous solutions, precipitate and extract suspensions in organic solvents. The brightest luminescence and greatest increase in luminescence intensity are observed at freezing of complex solvents with 1,2-dioxybenzene-3,5-disulfonic acid (DBSA) and iminodiacetic acid (IDA) and DBSA+EDTA, as well as in the case of benzene extracting of complexes with phenanthroline and salicylic acid. Otherwise the intensity increases 2-14-fold and for the complex of terbium with acetoacetic ester 36-fold.

  15. Quantitative luminescence imaging system

    Science.gov (United States)

    Erwin, David N.; Kiel, Johnathan L.; Batishko, Charles R.; Stahl, Kurt A.

    1990-01-01

    The QLIS images and quantifies low-level chemiluminescent reactions in an electromagnetic field. It is capable of real time nonperturbing measurement and simultaneous recording of many biochemical and chemical reactions such as luminescent immunoassays or enzyme assays. The system comprises image transfer optics, a low-light level digitizing camera with image intensifying microchannel plates, an image process or, and a control computer. The image transfer optics may be a fiber image guide with a bend, or a microscope, to take the light outside of the RF field. Output of the camera is transformed into a localized rate of cumulative digitalized data or enhanced video display or hard-copy images. The system may be used as a luminescent microdosimetry device for radiofrequency or microwave radiation, as a thermal dosimeter, or in the dosimetry of ultra-sound (sonoluminescence) or ionizing radiation. It provides a near-real-time system capable of measuring the extremely low light levels from luminescent reactions in electromagnetic fields in the areas of chemiluminescence assays and thermal microdosimetry, and is capable of near-real-time imaging of the sample to allow spatial distribution analysis of the reaction. It can be used to instrument three distinctly different irradiation configurations, comprising (1) RF waveguide irradiation of a small Petri-dish-shaped sample cell, (2) RF irradiation of samples in a microscope for the microscopie imaging and measurement, and (3) RF irradiation of small to human body-sized samples in an anechoic chamber.

  16. Thermally stimulated luminescence in ZnMoO{sub 4} crystals

    Energy Technology Data Exchange (ETDEWEB)

    Degoda, V.Ya.; Kogut, Ya.P.; Moroz, I.M. [Kyiv National Taras Shevchenko University, MSP 03680 Kyiv (Ukraine); Danevich, F.A. [Institute for Nuclear Research, MSP 03680 Kyiv (Ukraine)

    2017-03-15

    Thermally stimulated luminescence in ZnMoO{sub 4} crystals after X-ray irradiation at temperatures 8 K, 85 K and 295 K was studied. A theoretical model of crystal phosphor with three types of traps (shallow, phosphorescent and deep) is proposed. Simple analytic solutions of the kinetic equations system describing localized electrons on the traps and holes on recombination centres were obtained by using approximations accepted in the classic theories of crystal phosphors. Analytical curves describing thermally stimulated luminescence were obtained. A substantial effect of the different traps concentrations ratios on the thermally stimulated luminescence and conductivity peaks shapes is shown. A good agreement of the theoretical curves with the experimental data for the thermally stimulated luminescence peak at 114 K is obtained.

  17. Influence of Nano sized Silicon Oxide on the Luminescent Properties of Zn O Nanoparticles

    International Nuclear Information System (INIS)

    Shvalagin, V.; Grodziuk, G.; Kurmach, M.; Granchak, V.; Sarapulova, O.; Sherstiuk, V.

    2016-01-01

    For practical use of nano sized zinc oxide as the phosphor its luminescence quantum yields should be maximized. The aim of this work was to enhance luminescent properties of Zn O nanoparticles and obtain high-luminescent Zn O/SiO 2 composites using simpler approaches to colloidal synthesis. The luminescence intensity of zinc oxide nanoparticles was increased about 3 times by addition of silica nano crystals to the source solutions during the synthesis of Zn O nanoparticles. Then the quantum yield of luminescence of the obtained Zn O/SiO 2 composites is more than 30%. Such an impact of silica is suggested to be caused by the distribution of Zn O nano crystals on the surface of silica, which reduces the probability of separation of photo generated charges between the zinc oxide nanoparticles of different sizes, and as a consequence, there is a significant increase of the luminescence intensity of Zn O nanoparticles. This way of increasing nano-Zn O luminescence intensity facilitates its use in a variety of devices, including optical ultraviolet and visible screens, luminescent markers, antibacterial coatings, luminescent solar concentrators, luminescent inks for security printing, and food packaging with abilities of informing consumers about the quality and safety of the packaged product.

  18. Luminescence and luminescence quenching of Eu{sub 2}Mo{sub 4}O{sub 15}

    Energy Technology Data Exchange (ETDEWEB)

    Janulevicius, Matas; Grigorjevaite, Julija; Merkininkaite, Greta [Department of Analytical and Environmental Chemistry, Vilnius University, Naugarduko 24, LT-03225 Vilnius (Lithuania); Sakirzanovas, Simas [Department of Applied Chemistry, Vilnius University, Naugarduko 24, LT-03225 Vilnius (Lithuania); Katelnikovas, Arturas, E-mail: arturas.katelnikovas@chf.vu.lt [Department of Analytical and Environmental Chemistry, Vilnius University, Naugarduko 24, LT-03225 Vilnius (Lithuania)

    2016-11-15

    A polycrystalline Eu{sub 2}Mo{sub 4}O{sub 15} phosphor sample was prepared by high temperature solid state reaction. Phase purity and morphological features of the phosphor were investigated by X-ray diffraction and scanning electron microscopy, respectively. Reflectance spectra showed that the optical band gap of Eu{sub 2}Mo{sub 4}O{sub 15} is 2.95 eV. Phosphor emits intensive red light when excited with 394 and 465 nm radiation. Temperature dependent emission and luminescence lifetime measurements revealed that external and internal quantum yields decrease at the same rate and that luminescence quenches due to photoionization. The calculated external quantum yields for 394 and 465 nm excitation were 7.8% and 53.5%, respectively.

  19. Piezoelectrically-induced stress-luminescence phenomenon in CaAl2O4:Eu2+

    International Nuclear Information System (INIS)

    Wei, Yongbin; Wu, Zheng; Jia, Yanmin; Liu, Yongsheng

    2015-01-01

    Piezoelectrically-induced stress-luminescence in the CaAl 2 O 4 :Eu 2+ was investigated. Blue light that was visible to the naked eye could be observed in the dark when a pulse force of ∼7.7 kN was applied to the sample. The intensity of the stress-luminescence strongly depended on the magnitude of the applied force during a pulse cycle. The intensity decreased with repetitive application of pulse stress and was completely recovered after irradiation with ultraviolet light. It is suggested that the stress-luminescence effect in CaAl 2 O 4 :Eu 2+ arises from the piezoelectrically-induced de-trapping of the charge carriers. A CaAl 2 O 4 :Eu 2+ ceramic that exhibits a stress-luminescence effect has potential applications in smart stress optically-sensing devices. - Highlights: • The strong induced stress-luminescence in CaAl 2 O 4 :Eu 2+ was observed. • The stress-luminescent intensity strongly depends on the magnitude of force. • The stress-luminescence could be completely recovered after the UV irradiation. • The strong stress-luminescent effect is potential in stress-light sensors

  20. Metal-enhanced luminescence: Current trend and future perspectives- A review

    International Nuclear Information System (INIS)

    Ranjan, Rajeev; Esimbekova, Elena N.; Kirillova, Maria A.; Kratasyuk, Valentina A.

    2017-01-01

    Optically enhanced biosensing strategies are prerequisites for developing miniature and highly sensitive multiplexed analytical platforms. Such smart biosensing systems are highly promising for use in the fields of biomedicine and environmental monitoring. Optical signal enhancement during bioassays is attributed to the complex opto-electronic interactions of incoming photonic signals at the nanomaterial interface. Research on the use of metals other than gold and silver for such purposes tends to extend the spectral window to observe luminescence enhancement effects. Such manifold increase in luminescence may be explained by the principles of plasmon coupling, directional emission led high collection efficiency, Rayleigh scattering and related opto-electronic events. The present review begins with a mechanistic description of important phenomena associated with metal-induced luminescence enhancement, particularly focusing on the origin of metal-enhanced luminescence. This review further analyses the hybrid nanostructure capabilities responsible for maintaining unique opto-electronic properties during bio-functionalisation. Current research trends in this area, future scope of this field for designing useful bioassays and concluding remarks are then discussed. - Highlights: • Nanomaterials significantly differ from their bulk counterparts. • Strong and pronounced photophysical effects at the metal surface provide opportunities for designing novel biosensors. • Metal-enhanced luminescence increases the quantum yield of luminescent reactions. • Under optimal conditions, plasmon coupling enhances the optical effects at the nanometal surface.

  1. Metal-enhanced luminescence: Current trend and future perspectives- A review

    Energy Technology Data Exchange (ETDEWEB)

    Ranjan, Rajeev [Laboratory of Bioluminescent Biotechnologies, Department of Biophysics, Institute of Fundamental Biology and Biotechnology, Siberian Federal University, 79 Svobodny Prospect, Krasnoyarsk 660041 (Russian Federation); Esimbekova, Elena N., E-mail: esimbekova@yandex.ru [Laboratory of Bioluminescent Biotechnologies, Department of Biophysics, Institute of Fundamental Biology and Biotechnology, Siberian Federal University, 79 Svobodny Prospect, Krasnoyarsk 660041 (Russian Federation); Institute of Biophysics SB RAS, Federal Research Center “Krasnoyarsk Science Center SB RAS”, Akademgorodok 50/50, Krasnoyarsk 660036 (Russian Federation); Kirillova, Maria A. [Laboratory of Bioluminescent Biotechnologies, Department of Biophysics, Institute of Fundamental Biology and Biotechnology, Siberian Federal University, 79 Svobodny Prospect, Krasnoyarsk 660041 (Russian Federation); Kratasyuk, Valentina A. [Laboratory of Bioluminescent Biotechnologies, Department of Biophysics, Institute of Fundamental Biology and Biotechnology, Siberian Federal University, 79 Svobodny Prospect, Krasnoyarsk 660041 (Russian Federation); Institute of Biophysics SB RAS, Federal Research Center “Krasnoyarsk Science Center SB RAS”, Akademgorodok 50/50, Krasnoyarsk 660036 (Russian Federation)

    2017-06-08

    Optically enhanced biosensing strategies are prerequisites for developing miniature and highly sensitive multiplexed analytical platforms. Such smart biosensing systems are highly promising for use in the fields of biomedicine and environmental monitoring. Optical signal enhancement during bioassays is attributed to the complex opto-electronic interactions of incoming photonic signals at the nanomaterial interface. Research on the use of metals other than gold and silver for such purposes tends to extend the spectral window to observe luminescence enhancement effects. Such manifold increase in luminescence may be explained by the principles of plasmon coupling, directional emission led high collection efficiency, Rayleigh scattering and related opto-electronic events. The present review begins with a mechanistic description of important phenomena associated with metal-induced luminescence enhancement, particularly focusing on the origin of metal-enhanced luminescence. This review further analyses the hybrid nanostructure capabilities responsible for maintaining unique opto-electronic properties during bio-functionalisation. Current research trends in this area, future scope of this field for designing useful bioassays and concluding remarks are then discussed. - Highlights: • Nanomaterials significantly differ from their bulk counterparts. • Strong and pronounced photophysical effects at the metal surface provide opportunities for designing novel biosensors. • Metal-enhanced luminescence increases the quantum yield of luminescent reactions. • Under optimal conditions, plasmon coupling enhances the optical effects at the nanometal surface.

  2. Luminescence imaging of water during proton-beam irradiation for range estimation

    Energy Technology Data Exchange (ETDEWEB)

    Yamamoto, Seiichi, E-mail: s-yama@met.nagoya-u.ac.jp; Okumura, Satoshi; Komori, Masataka [Radiological and Medical Laboratory Sciences, Nagoya University Graduate School of Medicine, Nagoya 461-8673 (Japan); Toshito, Toshiyuki [Department of Proton Therapy Physics, Nagoya Proton Therapy Center, Nagoya City West Medical Center, Nagoya 462-8508 (Japan)

    2015-11-15

    Purpose: Proton therapy has the ability to selectively deliver a dose to the target tumor, so the dose distribution should be accurately measured by a precise and efficient method. The authors found that luminescence was emitted from water during proton irradiation and conjectured that this phenomenon could be used for estimating the dose distribution. Methods: To achieve more accurate dose distribution, the authors set water phantoms on a table with a spot scanning proton therapy system and measured the luminescence images of these phantoms with a high-sensitivity, cooled charge coupled device camera during proton-beam irradiation. The authors imaged the phantoms of pure water, fluorescein solution, and an acrylic block. Results: The luminescence images of water phantoms taken during proton-beam irradiation showed clear Bragg peaks, and the measured proton ranges from the images were almost the same as those obtained with an ionization chamber. Furthermore, the image of the pure-water phantom showed almost the same distribution as the tap-water phantom, indicating that the luminescence image was not related to impurities in the water. The luminescence image of the fluorescein solution had ∼3 times higher intensity than water, with the same proton range as that of water. The luminescence image of the acrylic phantom had a 14.5% shorter proton range than that of water; the proton range in the acrylic phantom generally matched the calculated value. The luminescence images of the tap-water phantom during proton irradiation could be obtained in less than 2 s. Conclusions: Luminescence imaging during proton-beam irradiation is promising as an effective method for range estimation in proton therapy.

  3. Luminescence imaging of water during proton-beam irradiation for range estimation

    International Nuclear Information System (INIS)

    Yamamoto, Seiichi; Okumura, Satoshi; Komori, Masataka; Toshito, Toshiyuki

    2015-01-01

    Purpose: Proton therapy has the ability to selectively deliver a dose to the target tumor, so the dose distribution should be accurately measured by a precise and efficient method. The authors found that luminescence was emitted from water during proton irradiation and conjectured that this phenomenon could be used for estimating the dose distribution. Methods: To achieve more accurate dose distribution, the authors set water phantoms on a table with a spot scanning proton therapy system and measured the luminescence images of these phantoms with a high-sensitivity, cooled charge coupled device camera during proton-beam irradiation. The authors imaged the phantoms of pure water, fluorescein solution, and an acrylic block. Results: The luminescence images of water phantoms taken during proton-beam irradiation showed clear Bragg peaks, and the measured proton ranges from the images were almost the same as those obtained with an ionization chamber. Furthermore, the image of the pure-water phantom showed almost the same distribution as the tap-water phantom, indicating that the luminescence image was not related to impurities in the water. The luminescence image of the fluorescein solution had ∼3 times higher intensity than water, with the same proton range as that of water. The luminescence image of the acrylic phantom had a 14.5% shorter proton range than that of water; the proton range in the acrylic phantom generally matched the calculated value. The luminescence images of the tap-water phantom during proton irradiation could be obtained in less than 2 s. Conclusions: Luminescence imaging during proton-beam irradiation is promising as an effective method for range estimation in proton therapy

  4. Influence of sample oxidation on the nature of optical luminescence from porous silicon

    International Nuclear Information System (INIS)

    Coulthard, I.; Antel, W. J. Jr.; Freeland, J. W.; Sham, T. K.; Naftel, S. J.; Zhang, P.

    2000-01-01

    Site-selective luminescence experiments were performed upon porous-silicon samples exposed to varying degrees of oxidation. The source of different luminescence bands was determined to be due to either quantum confinement in nanocrystalline silicon or defective silicon oxide. Of particular interest is the defective silicon-oxide luminescence band found at 2.1 eV, which was found to frequently overlap with a luminescence band from nanocrystalline silicon. Some of the historical confusion and debate with regards to the source of luminescence from porous silicon can be attributed to this overlap. (c) 2000 American Institute of Physics

  5. Hormesis response of marine and freshwater luminescent bacteria to metal exposure

    Directory of Open Access Journals (Sweden)

    KAILI SHEN

    2009-01-01

    Full Text Available The stimulatory effect of low concentrations of toxic chemicals on organismal metabolism, referred to as hormesis, has been found to be common in the widely used luminescence bioassay. This paper aims to study the hormesis phenomenon in both marine and freshwater luminescent bacteria, named Photobacterium phosphorem and Vibrio qinghaiensis. The effects of Cu (II, Zn (II, Cd (II and Cr (VI on luminescence of these two bacteria were studied for 0 to 75 minutes exposure by establishing dose- and time-response curves. A clear hormesis phenomenon was observed in all four testing metals at low concentrations under the condition of luminescence assays.

  6. Amino-Functionalized Luminescent Metal-Organic Framework Test Paper for Rapid and Selective Sensing of SO2 Gas and Its Derivatives by Luminescence Turn-On Effect.

    Science.gov (United States)

    Wang, Meng; Guo, Lin; Cao, Dapeng

    2018-03-06

    Rapid and selective sensing of sulfur dioxide (SO 2 ) gas has attracted more and more attention because SO 2 not only causes environmental pollution but also severely affects the health of human beings. Here we report an amino-functionalized luminescent metal-organic framework (MOF) material (i.e., MOF-5-NH 2 ) and further investigate its sensing property for SO 2 gas and its derivatives as a luminescent probe. The results indicate that the MOF-5-NH 2 probe can selectively and sensitively sense SO 2 derivatives (i.e., SO 3 2- ) in real time by a luminescence turn-on effect with a lower detection limit of 0.168 ppm and a response time of less than 15 s. Importantly, the luminescence turn-on phenomenon can be observed by the naked eye. We also assembled MOF-5-NH 2 into a test paper to achieve the aim of portable detection, and the lower-limit concentration of the test paper for sensing SO 2 in real time was found to be about 0.05 ppm. Moreover, MOF-5-NH 2 also shows good anti-interference ability, strong luminescence stability, and reusability, which means that this material is an excellent sensing candidate. The amino functionalization may also provide a modification strategy to design luminescent sensors for other atmospheric pollutants.

  7. Luminescence imaging of water during carbon-ion irradiation for range estimation

    Energy Technology Data Exchange (ETDEWEB)

    Yamamoto, Seiichi, E-mail: s-yama@met.nagoya-u.ac.jp; Komori, Masataka; Koyama, Shuji; Morishita, Yuki; Sekihara, Eri [Radiological and Medical Laboratory Sciences, Nagoya University Graduate School of Medicine, Higashi-ku, Nagoya, Aichi 461-8673 (Japan); Akagi, Takashi; Yamashita, Tomohiro [Hygo Ion Beam Medical Center, Hyogo 679-5165 (Japan); Toshito, Toshiyuki [Department of Proton Therapy Physics, Nagoya Proton Therapy Center, Nagoya City West Medical Center, Aichi 462-8508 (Japan)

    2016-05-15

    Purpose: The authors previously reported successful luminescence imaging of water during proton irradiation and its application to range estimation. However, since the feasibility of this approach for carbon-ion irradiation remained unclear, the authors conducted luminescence imaging during carbon-ion irradiation and estimated the ranges. Methods: The authors placed a pure-water phantom on the patient couch of a carbon-ion therapy system and measured the luminescence images with a high-sensitivity, cooled charge-coupled device camera during carbon-ion irradiation. The authors also carried out imaging of three types of phantoms (tap-water, an acrylic block, and a plastic scintillator) and compared their intensities and distributions with those of a phantom containing pure-water. Results: The luminescence images of pure-water phantoms during carbon-ion irradiation showed clear Bragg peaks, and the measured carbon-ion ranges from the images were almost the same as those obtained by simulation. The image of the tap-water phantom showed almost the same distribution as that of the pure-water phantom. The acrylic block phantom’s luminescence image produced seven times higher luminescence and had a 13% shorter range than that of the water phantoms; the range with the acrylic phantom generally matched the calculated value. The plastic scintillator showed ∼15 000 times higher light than that of water. Conclusions: Luminescence imaging during carbon-ion irradiation of water is not only possible but also a promising method for range estimation in carbon-ion therapy.

  8. Luminescence imaging of water during carbon-ion irradiation for range estimation

    International Nuclear Information System (INIS)

    Yamamoto, Seiichi; Komori, Masataka; Koyama, Shuji; Morishita, Yuki; Sekihara, Eri; Akagi, Takashi; Yamashita, Tomohiro; Toshito, Toshiyuki

    2016-01-01

    Purpose: The authors previously reported successful luminescence imaging of water during proton irradiation and its application to range estimation. However, since the feasibility of this approach for carbon-ion irradiation remained unclear, the authors conducted luminescence imaging during carbon-ion irradiation and estimated the ranges. Methods: The authors placed a pure-water phantom on the patient couch of a carbon-ion therapy system and measured the luminescence images with a high-sensitivity, cooled charge-coupled device camera during carbon-ion irradiation. The authors also carried out imaging of three types of phantoms (tap-water, an acrylic block, and a plastic scintillator) and compared their intensities and distributions with those of a phantom containing pure-water. Results: The luminescence images of pure-water phantoms during carbon-ion irradiation showed clear Bragg peaks, and the measured carbon-ion ranges from the images were almost the same as those obtained by simulation. The image of the tap-water phantom showed almost the same distribution as that of the pure-water phantom. The acrylic block phantom’s luminescence image produced seven times higher luminescence and had a 13% shorter range than that of the water phantoms; the range with the acrylic phantom generally matched the calculated value. The plastic scintillator showed ∼15 000 times higher light than that of water. Conclusions: Luminescence imaging during carbon-ion irradiation of water is not only possible but also a promising method for range estimation in carbon-ion therapy.

  9. Luminescence study of spodumene

    International Nuclear Information System (INIS)

    Isotani, S.; Fujii, A.T.; Antonini, R.; Pontuschka, W.M.; Rabani, S.R.; Furtado, W.W.

    1990-02-01

    A comparative study is made of the luminescence of five kinds of spodumene from Minas Gerais, Brazil, studied previously by optical absorption spectroscopy. Natural gemstones are used which, in the course of the experiments, were irradiated with X-rays. (L.C.) [pt

  10. Silicon: electrochemistry and luminescence

    NARCIS (Netherlands)

    Kooij, Ernst Stefan

    1997-01-01

    The electrochemistry of crystalline and porous silicon and the luminescence from porous silicon has been studied. One chapter deals with a model for the anodic dissolution of silicon in HF solution. In following chapters both the electrochemistry and various ways of generating visible

  11. Biosynthesis of myristic acid in luminescent bacteria

    International Nuclear Information System (INIS)

    Byers, D.M.

    1987-01-01

    In vivo pulse-label studies have demonstrated that luminescent bacteria can provide myritic acid (14:0) required for the synthesis of the luciferase substrate myristyl aldehyde. Luminescent wild type Vibrio harveyi incubated with [ 14 C] acetate in a nutrient-depleted medium accumulated substantial tree [ 14 C]fatty acid (up to 20% of the total lipid label). Radio-gas chromatography revealed that > 75% of the labeled fatty acid is 14:0. No free fatty acid was detected in wild type cells labeled prior to the development of bioluminescence in the exponential growth phase, or in a dark mutant of V. harveyi (mutant M17) that requires exogenous 14:0 for light emission. The preferential accumulation of 14:0 was not observed when wild type cells were labeled with [ 14 C]acetate in regular growth medium. Moreover, all V. harveyi strains exhibited similar fatty acid mass compositions regardless of the state of bioluminescence. Since earlier work has shown that a luminescence-related acyltransferase (defective in the M17 mutant) can catalyze the deacylation of fatty acyl-acyl carrier protein in vitro, the present results are consistent with a model in which this enzyme diverts 14:0 to the luminescence system during fatty acid biosynthesis. Under normal conditions, the supply of 14:0 by this pathway is tightly regulated such that bioluminescence development does not significantly alter the total fatty acid composition

  12. Conversion of the luminescence of laser dyes in opal matrices to stimulated emission

    International Nuclear Information System (INIS)

    Alimov, O K; Basiev, T T; Orlovskii, Yu V; Osiko, V V; Samoilovich, M I

    2008-01-01

    The luminescence and laser characteristics of a synthetic opal matrix filled with organic dyes are studied upon excitation by nanosecond laser pulses. The appearance of stimulated emission in a partially ordered scattering medium is investigated. It is shown that if the luminescence spectrum of a dye (oxazine-17) is located far outside the photonic bandgap of the opal matrix, stimulated emission along a preferential direction in the (111) plane is observed when pumping exceeds a threshold even without an external optical cavity. The stimulated emission spectrum is considerably narrower than the luminescence spectrum and consists of several narrow lines located within the dye luminescence band. If the luminescence spectrum of a dye (rhodamine 6G) overlaps with the photonic bandgap of the opal matrix, a different picture is observed. The loss of radiation in the matrix leads to the red shift of the luminescence spectrum, while the stimulated emission as in the case of oxazine-17 lies is observed within the luminescence band. (active media, lasers, and amplifiers)

  13. Splitting of the luminescent excited state of the uranyl ion

    International Nuclear Information System (INIS)

    Flint, C.D.; Sharma, P.; Tanner, P.A.

    1982-01-01

    The luminescence spectra of some uranyl compounds has been studied. It has been proposed that the splitting of the luminescent excited state of the uranyl ion is due to a descent in symmetry experienced by the uranyl ion when it is placed in a crystal field. In recent years there has been developed a highly successful model of the electronic structure of the uranyl ion. In this paper the authors use this model to interpret the luminescence spectra of a variety of uranyl compounds

  14. Sensitive luminescent determination of DNA using the terbium(III)-difloxacin complex

    International Nuclear Information System (INIS)

    Yegorova, Alla V.; Scripinets, Yulia V.; Duerkop, Axel; Karasyov, Alexander A.; Antonovich, Valery P.; Wolfbeis, Otto S.

    2007-01-01

    The interaction of the terbium-difloxacin complex (Tb-DFX) with DNA has been examined by using UV-vis absorption and luminescence spectroscopy. The Tb-DFX complex shows an up to 85-fold enhancement of luminescence intensity upon titration with DNA. The long decay times allow additional detection schemes like time-resolved measurements in microplate readers to enhance sensitivity by off-gating short-lived background luminescence. Optimal conditions are found at equimolar concentrations of Tb 3+ and DFX (0.1 or 1 μM) at pH 7.4. Under these conditions, the luminescence intensity is linearly dependent on the concentration of ds-DNAs and ss-DNA between 1-1500 ng mL -1 and 4.5-270 ng mL -1 , respectively. The detection limit is 0.5 ng mL -1 for ds-DNAs and 2 ng mL -1 for ss-DNA. The mechanism for the luminescence enhancement was also studied

  15. Novel and easy access to highly luminescent Eu and Tb doped ultra-small CaF2, SrF2 and BaF2 nanoparticles - structure and luminescence.

    Science.gov (United States)

    Ritter, Benjamin; Haida, Philipp; Fink, Friedrich; Krahl, Thoralf; Gawlitza, Kornelia; Rurack, Knut; Scholz, Gudrun; Kemnitz, Erhard

    2017-02-28

    A universal fast and easy access at room temperature to transparent sols of nanoscopic Eu 3+ and Tb 3+ doped CaF 2 , SrF 2 and BaF 2 particles via the fluorolytic sol-gel synthesis route is presented. Monodisperse quasi-spherical nanoparticles with sizes of 3-20 nm are obtained with up to 40% rare earth doping showing red or green luminescence. In the beginning luminescence quenching effects are only observed for the highest content, which demonstrates the unique and outstanding properties of these materials. From CaF 2 :Eu10 via SrF 2 :Eu10 to BaF 2 :Eu10 a steady increase of the luminescence intensity and lifetime occurs by a factor of ≈2; the photoluminescence quantum yield increases by 29 to 35% due to the lower phonon energy of the matrix. The fast formation process of the particles within fractions of seconds is clearly visualized by exploiting appropriate luminescence processes during the synthesis. Multiply doped particles are also available by this method. Fine tuning of the luminescence properties is achieved by variation of the Ca-to-Sr ratio. Co-doping with Ce 3+ and Tb 3+ results in a huge increase (>50 times) of the green luminescence intensity due to energy transfer Ce 3+ → Tb 3+ . In this case, the luminescence intensity is higher for CaF 2 than for SrF 2 , due to a lower spatial distance of the rare earth ions.

  16. A luminescent nisin biosensor

    Science.gov (United States)

    Immonen, Nina; Karp, Matti

    2006-02-01

    Nisin is a lantibiotic, an antibacterial peptide produced by certain Lactococcus lactis strains that kills or inhibits the growth of other bacteria. Nisin is widely used as a food preservative, and its long-time use suggests that it can be generally regarded as safe. We have developed a method for determining the amount of nisin in food samples that is based on luminescent biosensor bacteria. Bacterial luciferase operon luxABCDE was inserted into plasmid pNZ8048, and the construct was transformed by electroporation into Lc. lactis strain NZ9800, whose ability to produce nisin has been erased by deletion of the gene nisA. The operon luxABCDE has been modified to be functional in gram-positive bacteria to confer a bioluminescent phenotype without the requirement of adding an exogenous substrate. In the plasmid pNZ8048, the operon was placed under control of the nisin-inducible nisA promoter. The chromosomal nisRK genes of Lc. lactis NZ9800 allow it to sense nisin in the environment and relay this signal via signal transduction proteins NisK and NisR to initiate transcription from nisA promoter. In the case of our sensor bacteria, this leads to production of luciferase and, thus, luminescence that can be directly measured from living bacteria. Luminescence can be detected as early as within minutes of induction. The nisin assay described here provides a detection limit in the sub-picogram level per ml, and a linear area between 1 - 1000 pg/ml. The sensitivity of this assay exceeds the performance of all previously published methods.

  17. AgesGalore-A software program for evaluating spatially resolved luminescence data

    International Nuclear Information System (INIS)

    Greilich, S.; Harney, H.-L.; Woda, C.; Wagner, G.A.

    2006-01-01

    Low-light luminescence is usually recorded by photomultiplier tubes (PMTs) yielding integrated photon-number data. Highly sensitive CCD (charged coupled device) detectors allow for the spatially resolved recording of luminescence. The resulting two-dimensional images require suitable software for data processing. We present a recently developed software program specially designed for equivalent-dose evaluation in the framework of optically stimulated luminescence (OSL) dating. The software is capable of appropriate CCD data handling, parameter estimation using a Bayesian approach, and the pixel-wise fitting of functions for time and dose dependencies to the luminescence signal. The results of the fitting procedure and the equivalent-dose evaluation can be presented and analyzed both as spatial and as frequency distributions

  18. Monocrystalline silicon photovoltaic luminescent solar concentrator with 4.2% power conversion efficiency

    NARCIS (Netherlands)

    Desmet, L.; Ras, A.J.M.; Boer, de D.K.G.; Debije, M.G.

    2012-01-01

    We report conversion efficiencies of experimental single and dual light guide luminescent solar concentrators. We have built several 5¿¿cm×5¿¿cm and 10¿¿cm×10¿¿cm luminescent solar concentrator (LSC) demonstrators consisting of c-Si photovoltaic cells attached to luminescent light guides of Lumogen

  19. Dating Last Interglacial Coastal Systems Using New Feldspar Luminescence Technologies

    Science.gov (United States)

    Lamothe, M.

    2017-12-01

    The recent explosion in new luminescence dating technologies offers new opportunities to explore Quaternary marine coastal facies and landforms. However, tectonic and climatic processes controlling the development of Pleistocene coastal lithosomes are commonly obscured by their poorly constrained geological age. Luminescence dating of feldspar probes one order of magnitude deeper into geological time than radiocarbon and more than 5 times the current age range of quartz optically-stimulated luminescence, routinely used in luminescence dating. However, feldspar luminescence stimulated by infrared photons (eg IRSL) is hampered by anomalous fading. Successful correction methods developed by us over the last 15 years did produce sound chronologies but the fading-corrected ages carried large uncertainties. New approaches initiated by other laboratories, mainly in Europe, have isolated high temperature post-IRSL luminescence as this signal seems to be only slightly affected by fading. However, the gain in stability seems to be lessened due to bleachibility issues, generating age overestimations. We developed a novel protocol known as post-isothermal IRSL dating (Pit-IR) that focuses on a dual system of luminescence signals, probing low (50C) and medium (225C) temperature IRSL signals following isothermal treatments of various intensities. These protocols have been tested on Last interglacial coastal sediments in strikingly different GIA contexts along the Atlantic coastal areas of SE USA as well as from Morocco, Brazil and LIG sites in the Mediterranean basin. A systematic analysis of these results would suggest that a) falling-stages sequences are more commonly preserved as the OSL/IRSL ages are preferentially dating from the end of the MIS5e high stand and b) MIS5a marine sediments may be detectable away from areas generally thought to be affected by peripheral bulge collapse.

  20. Luminescence from Ce in sol-gel SiO{sub 2}

    Energy Technology Data Exchange (ETDEWEB)

    Kroon, R.E., E-mail: KroonRE@ufs.ac.za [Department of Physics, University of the Free State, IB51, Box 339, Bloemfontein 9300 (South Africa); Seed Ahmed, H.A.A.; Ntwaeaborwa, O.M. [Department of Physics, University of the Free State, IB51, Box 339, Bloemfontein 9300 (South Africa); Koao, L.F. [Department of Physics, University of the Free State (Qwaqwa Campus), Private Bag X13, Phuthaditjhaba 9866 (South Africa); Nagpure, I.M.; Gusowski, M.A. [Department of Physics, University of the Free State, IB51, Box 339, Bloemfontein 9300 (South Africa); Botha, J.R. [Department of Physics, Nelson Mandela Metropolitan University, Box 77000, Port Elizabeth 6031 (South Africa); Swart, H.C. [Department of Physics, University of the Free State, IB51, Box 339, Bloemfontein 9300 (South Africa)

    2012-05-15

    The sol-gel process provides an attractive low temperature alternative to the melt process for producing Ce-doped silica, but reports of the emission wavelength have not been consistent. In this paper, luminescence measurements using a variety of excitation methods, including cathodoluminescence not yet reported by other researchers, are compared and evaluated in the light of previously published data. Several papers report luminescence around 350 nm but emission near this wavelength was not found from our samples. This luminescence originates from Ce that has not yet been incorporated in the silica and is found in samples that have not undergone high temperature annealing. Our photoluminescence results from samples annealed in a reducing atmosphere suggest that emission from Ce incorporated in the silica lattice occurs near 455 nm, and some indication of the emission from Ce in amorphous clusters at 400 nm is also found. However, our results also confirm earlier indications that intrinsic defects in silica can create photoluminescence near both these wavelengths, which can make identification of the luminescence due to Ce difficult. Finally, it has been found that samples which have been annealed in air, and therefore display poor photoluminescence because most of the Ce occurs in the tetravalent form, are luminescent under electron beam excitation. It is suggested that during cathodoluminescence measurements Ce{sup 4+} ions capture electrons to form excited Ce{sup 3+} ions from which the luminescence originates.

  1. Conversion efficiency of implanted ions by confocal micro-luminescence mapping

    International Nuclear Information System (INIS)

    Deshko, Y.; Huang, Mengbing; Gorokhovsky, A.A.

    2013-01-01

    We report on the further development of the statistical approach to determine the conversion efficiency of implanted ions into emitting centers and present the measurement method based on the confocal micro-luminescence mapping. It involves the micro-luminescence mapping with a narrow-open confocal aperture, followed by the statistical analysis of the photoluminescence signal from an ensemble of emitting centers. The confocal mapping method has two important advantages compared to the recently discussed aperture-free method (J. Lumin. 131 (2011) 489): it is less sensitive to errors in the laser spot size and has a well defined useful area. The confocal mapping has been applied to the Xe center in diamond. The conversion efficiency has been found to be about 0.28, which is in good agreement with the results of the aperture-free method. - Highlights: ► Conversion efficiency of implanted ions into emitting centers – statistical approach. ► Micro-luminescence mapping with open and narrow confocal aperture – comparison. ► Advantages of the confocal micro-luminescence mapping. ► Confocal micro-luminescence mapping has been applied to the Xe center in diamond. ► The conversion efficiency has been found to be about 0.28.

  2. X-ray micro-modulated luminescence tomography (XMLT)

    Science.gov (United States)

    Cong, Wenxiang; Liu, Fenglin; Wang, Chao; Wang, Ge

    2014-01-01

    Imaging depth of optical microscopy has been fundamentally limited to millimeter or sub-millimeter due to strong scattering of light in a biological sample. X-ray microscopy can resolve spatial details of few microns deep inside a sample but contrast resolution is inadequate to depict heterogeneous features at cellular or sub-cellular levels. To enhance and enrich biological contrast at large imaging depth, various nanoparticles are introduced and become essential to basic research and molecular medicine. Nanoparticles can be functionalized as imaging probes, similar to fluorescent and bioluminescent proteins. LiGa5O8:Cr3+ nanoparticles were recently synthesized to facilitate luminescence energy storage with x-ray pre-excitation and subsequently stimulated luminescence emission by visible/near-infrared (NIR) light. In this paper, we propose an x-ray micro-modulated luminescence tomography (XMLT, or MLT to be more general) approach to quantify a nanophosphor distribution in a thick biological sample with high resolution. Our numerical simulation studies demonstrate the feasibility of the proposed approach. PMID:24663898

  3. Luminescence properties of isomeric and tautomeric lanthanide pyridinedicarboxylates

    International Nuclear Information System (INIS)

    Puntus, L.N.; Zolin, V.F.; Babushkina, T.A.; Kutuza, I.B.

    2004-01-01

    The luminescence and PMR spectra of europium salts of six isomers of 2,3-, 2,4-, 2,5-, 2,6-, 3,4-, and 3,5-pyridinedicarboxylic acids (PDA) had been studied. The distribution of the effective charge in the nearest surroundings of the Eu 3+ ion in these salts was evaluated from Stark splittings of electronic transitions. The values of relative integral intensities of electronic transitions 5 D 0 - 7 F J (J=0-4) in the luminescence spectra were reported. Compounds investigated were divided into three subgroups taking into account the details of the structure of the ligands and details of the luminescence spectra. The ligand coordination manners as well as the strength of interaction between lanthanide ion and ligands were confirmed by data of the PMR and IR spectroscopy

  4. Lanthanide-doped luminescent nanomaterials from fundamentals to bioapplications

    CERN Document Server

    Chen, Xueyuan; Tu, Datao

    2014-01-01

    Lanthanide-Doped Luminescent Nanomaterials reviews the latest advances in the development of lanthanide-doped luminescent inorganic nanoparticles for potential bioapplications. This book covers the chemical and physical fundamentals of these nanoparticles, such as the controlled synthesis methodology, surface modification chemistry, optical physics, and their promising applications in diverse bioassays, with an emphasis on heterogeneous and homogeneous in-vitro biodetection of tumor biomarkers. This book is intended for those readers who are interested in systematically understanding the materials design strategy, optical behavior of lanthanide ions, and practical bioapplications of lanthanide nanoparticles. It primarily focuses on the interdisciplinary frontiers in chemistry, physics and biological aspects of luminescent nanomaterials. All chapters were written by scientists active in this field and for a broad audience, providing both beginners and advanced researchers with comprehensive information on the ...

  5. Luminescence from potassium feldspars stimulated by infrared and green light

    DEFF Research Database (Denmark)

    Duller, G.A.T.; Bøtter-Jensen, L.

    1993-01-01

    A series of experiments are reported which investigate stimulated luminescence from potassium feldspar. The aim is to provide a basic phenomenological description of the response of the material to stimulation by heat, infrared radiation (875 DELTA 80 nm) and a green light wavelength band from 5 15...... to 560 nm. Two conclusions are drawn: firstly it is suggested that the majority of the trapped charge responsible for the infrared stimulated luminescence signal does not give rise to a thermoluminescence signal, and secondly that a large traction of the two optically stimulated luminescence signals...

  6. On the half-life of luminescence signals in dosimetric applications: A unified presentation

    Science.gov (United States)

    Pagonis, V.; Kitis, G.; Polymeris, G. S.

    2018-06-01

    Luminescence signals from natural and man-made materials are widely used in dosimetric and dating applications. In general, there are two types of half-lives of luminescence signals which are of importance to experimental and modeling work in this research area. The first type of half-life is the time required for the population of the trapped charge in a single trap to decay to half its initial value. The second type of half-life is the time required for the luminescence intensity to drop to half of its initial value. While there a handful of analytical expressions available in the literature for the first type of half-life, there are no corresponding analytical expressions for the second type. In this work new analytical expressions are derived for the half-life of luminescence signals during continuous wave optical stimulation luminescence (CW-OSL) or isothermal luminescence (ITL) experiments. The analytical expressions are derived for several commonly used luminescence models which are based on delocalized transitions involving the conduction band: first and second order kinetics, empirical general order kinetics (GOK), mixed order kinetics (MOK) and the one-trap one-recombination center (OTOR) model. In addition, half-life expressions are derived for a different type of luminescence model, which is based on localized transitions in a random distribution of charges. The new half-life expressions contain two parts. The first part is inversely proportional to the thermal or optical excitation rate, and depends on the experimental conditions and on the cross section of the relevant luminescence process. The second part is characteristic of the optical and/or thermal properties of the material, as expressed by the parameters in the model. A new simple and quick method for analyzing luminescence signals is developed, and examples are given of applying the new method to a variety of dosimetric materials. The new test allows quick determination of whether a set of

  7. Integrated light in direct excitation and energy transfer luminescence

    OpenAIRE

    Chimczak, Eugeniusz

    2007-01-01

    Integrated light in direct excitation and energy transfer luminescence has been investigated. In the investigations reported here, monomolecular centers were taken into account. It was found that the integrated light is equal to the product of generation rate and time of duration of excitation pulse for both direct excitation and energy transfer luminescence.

  8. UV Thermoluminescence and Phosphorescence Properties of Mg2+ and Nd3+ Doped Nanostructured Al2O3

    International Nuclear Information System (INIS)

    Bitencourt, J F S; Goncalves, K A; Tatumi, S H; Marcos, P J B

    2010-01-01

    Mg 2+ and Nd 3+ doped aluminium oxide samples were produced by polymer calcination method. Mg 2+ doped samples did not exhibited significant fluorescence emission, using IR (LED, emission centered at 862nm) or green (Xe-lamp plus optical filter, emission centered at 520 nm) sources. Nonetheless, high thermostimulated luminescence was detected, with high emission peak at 190 0 C. A nanoscopic layer (about 50 nm width) of magnesium spinel was observed by Transmission Electronic Microscopy (TEM) for 2.61mol% doped sample; this layer can be the responsible for TL enhancement. Nd 3+ doped sample exhibited low phosphorescence emission in the UV (Schott U-340) using IR source. TL peaks were detected at 185 and 265 0 C; the intermediary peak showed the highest emission. Occurrence of NdAl and NdAl 2 structures were detected in 5 mol% doped sample and NdAl 2 and NdAl 4 structures in 10 mol% doped sample.

  9. The research of characteristic difference of selected frequency luminescence for desert sand

    International Nuclear Information System (INIS)

    Liu Chao; Wei Mingjian; Li Huhou

    2011-01-01

    The characters of selected frequency luminescence of four groups of samples from Badain Jaran desert are measured by BG2003 luminescence spectrograph. The measurement subjects include selected frequency optical stimulate luminescence spectrum, selected frequency thermoluminescence spectrum and the dose response curve. A double-peak map is obtained by the result from all groups of data and spectrum. The difference is emerged between each group. The optical stimulate luminescence and thermoluminescence is applied in the measurement process. The dispersion of photon count on every response wavelength is analyzed. Based on the analysis, a better result can be gained by selected frequency thermoluminescence. (authors)

  10. Thermal quenching of luminescence processes in feldspars

    DEFF Research Database (Denmark)

    Poolton, N.R.J.; Bøtter-Jensen, L.; Duller, G.A.T.

    1995-01-01

    , which display very different behaviour. The first involves the internal transitions of common transition metal ions. The second is typical of centres not displaying excited states within the band gap that are likely to arise from direct recombination between the conduction band and the ground state......The technique of optically stimulated luminescence has important uses in the dose evaluation of irradiated feldspars. The luminescence process involves the eviction of electrons from donor traps, charge transfer through the conduction band, and recombination at acceptor sites; each...

  11. A luminescence lifetime assisted ratiometric fluorimeter for biological applications

    Science.gov (United States)

    Lam, Hung; Kostov, Yordan; Rao, Govind; Tolosa, Leah

    2009-12-01

    In general, the most difficult task in developing devices for fluorescence ratiometric sensing is the isolation of signals from overlapping emission wavelengths. Wavelength discrimination can be achieved by using monochromators or bandpass filters, which often lead to decreased signal intensities. The result is a device that is both complex and expensive. Here we present an alternative system—a low-cost standalone optical fluorimeter based on luminescence lifetime assisted ratiometric sensing (LARS). This paper describes the principle of this technique and the overall design of the sensor device. The most significant innovation of LARS is the ability to discriminate between two overlapping luminescence signals based on differences in their luminescence decay rates. Thus, minimal filtering is required and the two signals can be isolated despite significant overlap of luminescence spectra. The result is a device that is both simple and inexpensive. The electronic circuit employs the lock-in amplification technique for the signal processing and the system is controlled by an onboard microcontroller. In addition, the system is designed to communicate with external devices via Bluetooth.

  12. LUMINESCENT PROPERTIES OF SILICATE GLASSES WITH CERIUM IONS AND ANTIMONY

    Directory of Open Access Journals (Sweden)

    A. M. Klykova

    2014-05-01

    Full Text Available The paper deals with the results of an experimental study of luminescence excitation spectra and luminescence of silicate glasses containing cerium ions and antimony. The aim of this work was to study the features of the luminescence and the effect of UV irradiation and heat treatment on luminescence and the state of cerium ions and antimony in glass. We investigated glass system Na2O-ZnO-Al2O3-SiO2-NaF-NaBr with additives CeO2 and Sb2O3. Synthesis was carried out in platinum crucibles in the air at 14500C. The samples were polished glass plates with a thickness of 0.5-1 mm. UV irradiation was carried out with a mercury lamp having a wide range of radiation in the spectral range 240-390 nm. It was conducted in a Nabertherm muffle furnaces. Luminescence spectra and excitation spectra were measured using a spectrofluorimeter MPF-44A (PerkinElmer at the room temperature. Measured luminescence spectra were corrected in view of the spectral sensitivity of the photodetector for spectrofluorimeter. Adjustment of the excitation spectra for the spectral dependence of the intensity of the excitation source was not carried out. During the experiments it was found that in silicate glasses Sb3+ ions can exist in two energy states, which corresponds to a different environment with oxygen ions. Heat treatment of these glasses in an oxidizing atmosphere leads to an increase in ion concentration of Sb3+ ions with a greater amount of oxygen in the environment. In glasses containing antimony and cerium ions, ultraviolet irradiation causes a change in the valence of cerium ions and antimony, which is accompanied by luminescence quenching. Subsequent heat treatment of glass leads to the inverse processes and restore luminescence excitation spectra. The study of fluorescent properties of silicate glasses with cerium and antimony ions led to the conclusion of the practical significance of this work. Promising multifunctional materials can be created on the basis of

  13. Nanoscale luminescent lanthanide-based metal–organic frameworks: properties, synthesis, and applications

    Energy Technology Data Exchange (ETDEWEB)

    Hu, Dongqin; Song, Yonghai; Wang, Li, E-mail: lwanggroup@aliyun.com [Jiangxi Normal University, Key Laboratory of Functional Small Organic Molecule, Ministry of Education, Key Laboratory of Chemical Biology, Jiangxi Province, College of Chemistry and Chemical Engineering (China)

    2015-07-15

    Nanoscale luminescent lanthanide-based metal–organic frameworks (NLLn-MOFs) possess superior optical and physical properties such as higher luminescent lifetime, quantum yield, high stability, high surface area, high agent loading, and intrinsic biodegradability, and therefore are regarded as a novel generation of luminescent material compared with bulk lanthanide-based metal–organic frameworks (Ln-MOFs). Traditional luminescent Ln-MOFs have been well studied; however, NLLn-MOFs taking the advantages of nanomaterials have attracted extensive investigations for applications in optical imaging in living cells, light-harvesting, and sensing. In this review, we provide a survey of the latest progresses made in developing NLLn-MOFs, which contains the fundamental optical features, synthesis, and their potential applications. Finally, the future prospects and challenges of the rapidly growing field are summarized.

  14. Comparison of conventional chemotherapy, stealth liposomes and temperature-sensitive liposomes in a mathematical model.

    Directory of Open Access Journals (Sweden)

    Astrid Gasselhuber

    Full Text Available Various liposomal drug carriers have been developed to overcome short plasma half-life and toxicity related side effects of chemotherapeutic agents. We developed a mathematical model to compare different liposome formulations of doxorubicin (DOX: conventional chemotherapy (Free-DOX, Stealth liposomes (Stealth-DOX, temperature sensitive liposomes (TSL with intra-vascular triggered release (TSL-i, and TSL with extra-vascular triggered release (TSL-e. All formulations were administered as bolus at a dose of 9 mg/kg. For TSL, we assumed locally triggered release due to hyperthermia for 30 min. Drug concentrations were determined in systemic plasma, aggregate body tissue, cardiac tissue, tumor plasma, tumor interstitial space, and tumor cells. All compartments were assumed perfectly mixed, and represented by ordinary differential equations. Contribution of liposomal extravasation was negligible in the case of TSL-i, but was the major delivery mechanism for Stealth-DOX and for TSL-e. The dominant delivery mechanism for TSL-i was release within the tumor plasma compartment with subsequent tissue- and cell uptake of released DOX. Maximum intracellular tumor drug concentrations for Free-DOX, Stealth-DOX, TSL-i, and TSL-e were 3.4, 0.4, 100.6, and 15.9 µg/g, respectively. TSL-i and TSL-e allowed for high local tumor drug concentrations with reduced systemic exposure compared to Free-DOX. While Stealth-DOX resulted in high tumor tissue concentrations compared to Free-DOX, only a small fraction was bioavailable, resulting in little cellular uptake. Consistent with clinical data, Stealth-DOX resulted in similar tumor intracellular concentrations as Free-DOX, but with reduced systemic exposure. Optimal release time constants for maximum cellular uptake for Stealth-DOX, TSL-e, and TSL-i were 45 min, 11 min, and <3 s, respectively. Optimal release time constants were shorter for MDR cells, with ∼4 min for Stealth-DOX and for TSL-e. Tissue concentrations

  15. Characterization and luminescent properties of thermally annealed olivines

    International Nuclear Information System (INIS)

    Colin-Garcia, Maria; Correcher, Virgilio; Garcia-Guinea, Javier; Heredia-Barbero, Alejandro; Roman-Lopez, Jesus; Ortega-Gutierrez, Fernando; Negron-Mendoza, Alicia; Ramos-Bernal, Sergio

    2013-01-01

    Olivine is an iron-magnesium solid solution silicate (Mg,Fe) 2 SiO 4 and it is probably one of the most abundant mineral phase in the Solar System, it is present in the primitive carbonaceous meteorites (i.e Allende), and in ordinary chondritic meteorite, comets or terrestrial planets. The olivine grains in those bodies have been exposed to different radiation sources like UV, electrons, cosmic radiation, etc. Here, we explore the effect of ionizing and non ionizing radiation on the luminescence emission of the two well-characterised olivine samples from Mexico and Spain by means of cathodoluminescence and thermoluminescence. The analyses by X-ray dispersive energies in the scanning electron microscopy show differences between the samples in the amount of iron and magnesium and also show traces of rare elements. Olivine exhibits spectral cathodoluminescence emissions of low intensity, explained for the quenching of the luminescence of the iron, and sharp signals assigned as impurities. Cathodoluminescence and thermoluminescence glow curves of the natural, and UV induced olivine samples were obtained. Our results show that thermal treatments at 1100 °C change the mineral molecular structure and the luminescence properties of this mineral phase. These results confirm an active participation of physical factors influencing the luminescent properties of olivine. -- Highlights: ► Luminescent properties of two olivines samples (Mexican and Spanish) were explored. ► EDS show different iron and magnesium content and traces of rare elements on both. ► Olivine exhibits spectral CL emissions of low intensity due to the quenching of iron. ► Treatments at 1100 °C change the mineral structure and its response to UV radiation

  16. Effects of Iranian Economic Reforms on Equity in Social and Healthcare Financing: A Segmented Regression Analysis

    Science.gov (United States)

    Bayati, Mohsen

    2018-01-01

    Objectives One of the main objectives of the Targeted Subsidies Law (TSL) in Iran was to improve equity in healthcare financing. This study aimed at measuring the effects of the TSL, which was implemented in Iran in 2010, on equity in healthcare financing. Methods Segmented regression analysis was applied to assess the effects of TSL implementation on the Gini and Kakwani indices of outcome variables in Iranian households. Data for the years 1977-2014 were retrieved from formal databases. Changes in the levels and trends of the outcome variables before and after TSL implementation were assessed using Stata version 13. Results In the 33 years before the implementation of the TSL, the Gini index decreased from 0.401 to 0.381. The Gini index and its intercept significantly decreased to 0.362 (p<0.001) 5 years after the implementation of the TSL. There was no statistically significant change in the gross domestic product or inflation rate after TSL implementation. The Kakwani index significantly increased from -0.020 to 0.007 (p<0.001) before the implementation of the TSL, while we observed no statistically significant change (p=0.81) in the Kakwani index after TSL implementation. Conclusions The TSL reform, which was introduced as part of an economic development plan in Iran in 2010, led to a significant reduction in households’ income inequality. However, the TSL did not significantly affect equity in healthcare financing. Hence, while measuring the long-term impact of TSL is paramount, healthcare decision-makers need to consider the efficacy of the TSL in order to develop plans for achieving the desired equity in healthcare financing. PMID:29631352

  17. Real-time luminescence from Al2O3 fiber dosimeters

    International Nuclear Information System (INIS)

    Polf, J.C.; Yukihara, E.G.; Akselrod, M.S.; McKeever, S.W.S.

    2004-01-01

    The real-time luminescence signal from Al 2 O 3 single crystal fibers, monitored during simultaneous irradiation and optical stimulation, was investigated using computer simulations and experimental measurements. Both radioluminescence (RL) and optically stimulated luminescence (OSL) signals were studied. The simulations were performed initially using a simple one-trap/one-recombination-center energy band model, and then extended to include shallow and deep electron traps as well. Real-time luminescence experiments were performed for different radiation dose rates and optical stimulation powers using periodic laser stimulation of the samples through a fiber optic cable, and the experimental results were compared with the predictions from the computer simulations. The luminescence signal was observed, both theoretically and experimentally, to increase from its initial value to a steady-state level. The steady-state RL and OSL levels were found to be dependent on dose rate, the steady-state level of the real-time OSL being independent of laser power. It was also shown that the total integrated absorbed dose throughout the irradiation period can be determined by correcting the real-time OSL signal for depletion caused by each laser stimulation pulse. The effects of the shallow and deep traps on the time-dependence of the real-time luminescence signal were studied comparing the experimental data from several Al 2 O 3 fibers known to have different trapping state concentrations. The additional traps were found to slow the response of the real-time luminescence such that the time to reach steady state was increased as the additional traps were added

  18. Synthesis and luminescent properties of PEO/lanthanide oxide nanoparticle hybrid films

    International Nuclear Information System (INIS)

    Goubard, F.; Vidal, F.; Bazzi, R.; Tillement, O.; Chevrot, C.; Teyssie, D.

    2007-01-01

    In this study, we investigate the optical properties of lanthanide oxide nanoparticles dispersed in poly(ethylene oxide) (PEO) network as thermally stable polymeric films. The aim of this work is both to keep a good optical transparency in the visible domain and to obtain luminescent materials after incorporation of nanoparticles. For this purpose, we develop luminescent nanocrystals of oxides containing terbium ion as a doping element in Gd 2 O 3 . These sub-5-nm lanthanide oxides nanoparticles have been prepared by direct oxide precipitation in high-boiling polyalcohol solutions and characterized by luminescence spectroscopy. PEO/lanthanide oxide nanohybrid films are prepared by radical polymerization of poly(ethylene glycol) methacrylate after introduction of lanthanide oxide particles. As a first result; the obtained films present interesting luminescence properties with a very low lanthanide oxide content (up to 0.29 wt%). Furthermore, these films are still transparent and keep their original mechanical properties. Prior to describe the specific applications to optical use, we report here the dynamic mechanical analysis (DMA), X-ray diffraction (XRD) analysis, transmission electron microscopy (TEM), and luminescent properties of. nanohybrid films

  19. Scintillation and optical stimulated luminescence of Ce-doped CaF2

    International Nuclear Information System (INIS)

    Yanagida, Takayuki; Fujimoto, Yutaka; Watanabe, Kenichi; Fukuda, Kentaro; Kawaguchi, Noriaki; Miyamoto, Yuka; Nanto, Hidehito

    2014-01-01

    Scintillation and optical stimulated luminescence of Ce 0.1–20% doped CaF 2 crystals prepared by Tokuyama Corp. were investigated. In X-ray induced scintillation spectra, luminescence due to Ce 3+ 5d–4f transition appeared around 320 nm with typically 40 ns decay time. By 241 Am 5.5 MeV α-ray irradiation, 0.1% doped one showed the highest scintillation light yield and the light yield monotonically decreased with Ce concentrations. Optically stimulated luminescence after X-ray irradiation was observed around 320 nm under 550 or 830 nm stimulation in all samples. As a result, intensities of optically stimulated luminescence were proportional to Ce concentrations. Consequently, scintillation and optically stimulated luminescence resulted to have a complementary relation in Ce-doped CaF 2 system. - Highlights: • Optical, scintillation, and OSL properties of Ce 0.1–20% doped CaF 2 were studied. • Scintillation light yield exhibited inverse proportionality to Ce concentrations. • OSL intensities showed proportionality to Ce concentrations. • Complementary relation of scintillation and OSL was experimentally confirmed

  20. The effect of thermal oxidation on the luminescence properties of nanostructured silicon.

    Science.gov (United States)

    Liu, Lijia; Sham, Tsun-Kong

    2012-08-06

    Herein is reported a detailed study of the luminescence properties of nanostructured Si using X-ray excited optical luminescence (XEOL) in combination with X-ray absorption near-edge structures (XANES). P-type Si nanowires synthesized via electroless chemical etching from Si wafers of different doping levels and porous Si synthesized using electrochemical method are examined under X-ray excitation across the Si K-, L(3,2) -, and O K-edges. It is found that while as-prepared Si nanostructures are weak light emitters, intense visible luminescence is observed from thermally oxidized Si nanowires and porous Si. The luminescence mechanism of Si upon oxidation is investigated by oxidizing nanostructured Si at different temperatures. Interestingly, the two luminescence bands observed show different response with the variation of absorption coefficient upon Si and O core-electron excitation in elemental silicon and silicon oxide. A correlation between luminescence properties and electronic structures is thus established. The implications of the finding are discussed in terms of the behavior of the oxygen deficient center (OCD) and non-bridging oxygen hole center (NBOHC). Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  1. A study of luminescence and absorption spectra of GaP

    International Nuclear Information System (INIS)

    Mansour, H.M.M.; Abdel Wahab, S.M.

    1994-08-01

    Experimental luminescence and absorption spectra of GaP at room temperature are presented. A theoretical analysis has been performed on the luminescence and absorption spectra in GaP. The experimental data are in good agreement with the theoretical results. (author). 18 refs, 8 figs

  2. Study on the light-color mixing of rare earth luminescent materials for anti-counterfeiting application

    Science.gov (United States)

    Zhang, Jishu; Zhang, Yingzi; Tao, Jin; Zhu, Yanan

    2018-04-01

    In order to find out the light color mixing mechanism of rare earth luminescent materials used in anti-counterfeiting fibers, we prepared three kinds of rare earth luminescent materials according to RGB tri-primary color, and mixed it together to form different mixtures in certain proportion. The phase structures of the luminescent material monomers were measured by x-ray diffractometer. The photochromic properties of the luminescent materials were tested and analyzed by fluorescence spectrophotometer. The results show that the light color mixing was consistent with the blending principle of additive color, but not the same because of the photochromic properties of rare earth luminescent materials, and we explored the reasons in the light wavelength and intensity. It was found that the enhancement of the luminescence intensity of the mixture on account of the superimposing of luminescence.

  3. Study of the luminescence properties of a natural amazonite

    Energy Technology Data Exchange (ETDEWEB)

    Correcher, V., E-mail: v.correcher@ciemat.es [CIEMAT, Av. Complutense 22, Madrid 28040 (Spain); Garcia-Guinea, J. [Museo Nacional de Ciencias Naturales, CSIC, C/Jose Gutierrez Abascal 2, Madrid 28006 (Spain)

    2011-09-15

    Most gemstones, being natural materials (silicates, carbonates, phosphates, etc.), exhibit luminescence emission. This property could be potentially employed for personal dosimetry in the case of radiation accident or radiological terrorism where conventional monitoring has not been established. We, herein, report on the thermoluminescence (TL), radioluminescence (RL) and infra-red stimulated luminescence (IRSL) response of a well-characterised natural amazonite (KAlSi{sub 3}O{sub 8}) that, due to its bright blue-green colour when polished, is used as a gemstone. The luminescence emission wavelengths, intensities and thermal kinetics of the amazonite luminescence curves reveal that the ultraviolet band measured on amazonite aliquots is similar to other common K-rich feldspars. On this basis, one can conclude (i) association between twinning and the UV-blue TL emission can be related to structural defects located in the twin-domain boundaries where ionic alkali-self-diffusion, irreversible water losses and irreversible dehydroxylation processes can be involved. (ii) Amazonite exhibits a complex structure with several planar defects (twinning and exsolution interphases which can hold hydroxyl groups, water molecules, etc.) and point defects (impurities, Na, Pb, Mn, etc.) that can act as luminescence centres, and in fact, green and red emissions are respectively associated with the presence of Mn and Fe impurities. Finally, (iv) the thermal stability tests performed on the TL emission of the amazonite confirm a continuum in the trap distribution, i.e. progressive changes in the glow curve shape, intensity and temperature position of the maximum peak.

  4. Size-dependent abnormal thermo-enhanced luminescence of ytterbium-doped nanoparticles.

    Science.gov (United States)

    Cui, Xiangshui; Cheng, Yao; Lin, Hang; Huang, Feng; Wu, Qingping; Wang, Yuansheng

    2017-09-21

    Thermal quenching above 300 K is widely expected in photoluminescence. Luminescence quenching is usually ascribed to the non-radiative relaxation of excited electrons to the ground state of the activators, during which a high temperature always plays a role in pushing the excited electrons towards the quenching channels, leading to thermal quenching. For the lanthanide-doped nanoparticles, however, there is a special luminescence quenching channel that does not exist in their bulk counterparts, i.e., energy migration-induced surface quenching. Herein, a size-dependent abnormal thermal enhancement of luminescence in the temperature range of 300 K to 423 K in the ytterbium-doped fluoride nanoparticles is presented for the first time. Importantly, in this work, we originally demonstrate that the energy migration-induced surface quenching can be suppressed by increasing temperature, which results in the abnormal thermal enhancement of luminescence. According to the temperature-dependent X-ray diffraction and lifetime analyses, an underlying mechanism based on the effect of thermal lattice expansion on ytterbium-mediated energy migration is proposed. This new finding adds new insights to the size effect on the luminescent characteristics of nanoparticles, which could be utilized to construct some unique nanostructures, especially for many important temperature-related purposes, such as thermal sensing technology.

  5. Iron control of the Vibrio fischeri luminescence system in Escherichia coli.

    Science.gov (United States)

    Dunlap, P V

    1992-01-01

    Iron influences luminescence in Vibrio fischeri; cultures iron-restricted for growth rate induce luminescence at a lower optical density (OD) than faster growing, iron-replete cultures. An iron restriction effect analogous to that in V. fischeri (slower growth, induction of luminescence at a lower OD) was established using Escherichia coli tonB and tonB+ strains transformed with recombinant plasmids containing the V. fischeri lux genes (luxR luxICDABEG) and grown in the presence and absence of the iron chelator ethylenediamine-di(o-hydroxylphenyl acetic acid) (EDDHA). This permitted the mechanism of iron control of luminescence to be examined. A fur mutant and its parent strain containing the intact lux genes exhibited no difference in the OD at induction of luminescence. Therefore, an iron-binding repressor protein apparently is not involved in iron control of luminescence. Furthermore, in the tonB and in tonB+ strains containing lux plasmids with Mu dI(lacZ) fusions in luxR, levels of beta-galactosidase activity (expression from the luxR promoter) and luciferase activity (expression from the luxICDABEG promoter) both increased by a similar amount (8-9 fold each for tonB, 2-3 fold each for tonB+) in the presence of EDDHA. Similar results were obtained with the luxR gene present on a complementing plasmid. The previously identified regulatory factors that control the lux system (autoinducer-LuxR protein, cyclic AMP-cAMP receptor protein) differentially control expression from the luxR and luxICDABEG promoters, increasing expression from one while decreasing expression from the other. Consequently, these results suggest that the effect of iron on the V. fischeri luminescence system is indirect.

  6. Luminescence properties of KCl:Ag{sup -} crystals excited near the fundamental absorption edge

    Energy Technology Data Exchange (ETDEWEB)

    Kawai, Taketoshi, E-mail: buri@p.s.osakafu-u.ac.jp [Department of Physical Science, Graduate School of Science, Osaka Prefecture University, Gakuen-cho 1-1, Naka-ku, Sakai, Osaka 599-8531 (Japan); Hirai, Takeshi [Department of Physical Science, Faculty of Science and Engineering, Ritsumeikan University, Noji Higashi 1-1-1, Kusatsu, Shiga 525-8577 (Japan)

    2012-02-15

    Luminescence properties of KCl single crystals doped with Ag{sup -} centers have been investigated under various excitation energies around the fundamental absorption edge at low temperatures. Under the excitation at 6.89 eV, which is lower than the intrinsic exciton energy by 0.87 eV, the A Prime luminescence band due to the intraionic transition in the Ag{sup -} ion is dominantly observed at 2.91 eV. On the other hand, the excitation at 6.66 eV induces a broad luminescence band at 2.60 eV in addition to the A Prime luminescence band. From the comparison with the localized excitons in KCl:I crystals, the 2.60 eV luminescence band is attributed to the two-center type localized exciton related with the Ag{sup -} ion. The adiabatic potential energy surfaces of the excited states in the Ag{sup -} center and the localized exciton in KCl:Ag{sup -} are discussed. - Highlights: Black-Right-Pointing-Pointer We study the luminescence properties of KCl single crystals doped with Ag{sup -} ions. Black-Right-Pointing-Pointer The excitation around the absorption edge induces a broad luminescence at 2.60 eV. Black-Right-Pointing-Pointer The 2.60 eV luminescence is attributed to the exciton localized at the Ag{sup -} ion. Black-Right-Pointing-Pointer The localized exciton has the two-center type configuration of the relaxed exciton.

  7. Luminescence evolution of porous GaN thin films prepared via UV-assisted electrochemical etching

    International Nuclear Information System (INIS)

    Cheah, S.F.; Lee, S.C.; Ng, S.S.; Yam, F.K.; Abu Hassan, H.; Hassan, Z.

    2015-01-01

    Porous gallium nitride (GaN) thin films with different surface morphologies and free carriers properties were fabricated from Si-doped GaN thin films using ultra-violet assisted electrochemical etching approach under various etching voltages. Fluctuation of luminescence signals was observed in the photoluminescence spectra of porous GaN thin films. Taking advantage of the spectral sensitivity of infrared attenuated total reflection spectroscopy on semiconductor materials, roles of free carriers and porous structure in controlling luminescence properties of GaN were investigated thoroughly. The results revealed that enhancement in luminescence signal is not always attained upon porosification. Although porosification is correlated to the luminescence enhancement, however, free carrier is the primary factor to enhance luminescence intensity. Due to unavoidable significant reduction of free carriers from Si-doped GaN in the porosification process, control of etching depth (i.e., thickness of porous layer formed from the Si-doped layer) is critical in fabricating porous GaN thin film with enhanced luminescence response. - Highlights: • Various pore morphologies with free carrier properties are produced by Si-doped GaN. • Free carriers are important to control the luminescence signal of porous GaN. • Enhancement of luminescence signal relies on the pore depth of Si-doped layer

  8. Luminescence Properties of Self-Aggregating TbIII-DOTA-Functionalized Calix[4]arenes

    Science.gov (United States)

    Mayer, Florian; Tiruvadi Krishnan, Sriram; Schühle, Daniel T.; Eliseeva, Svetlana V.; Petoud, Stéphane; Tóth, Éva; Djanashvili, Kristina

    2018-01-01

    Self-aggregating calix[4]arenes carrying four DOTA ligands on the upper rim for stable complexation of paramagnetic GdIII-ions have already been proposed as MRI probes. In this work, we investigate the luminescence properties of TbIII-DOTA-calix[4]arene-4OPr containing four propyl-groups and compare them with those of the analogue substituted with a phthalimide chromophore (TbIII-DOTA-calix[4]arene-3OPr-OPhth). We show that, given its four aromatic rings, the calix[4]arene core acts as an effective sensitizer of Tb-centered luminescence. Substituents on the lower rim can modulate the aggregation behavior, which in turn determines the luminescence properties of the compounds. In solid state, the quantum yield of the phthalimide derivative is almost three times as high as that of the propyl-functionalized analogue demonstrating a beneficial role of the chromophore on Tb-luminescence. In solution, however, the effect of the phthalimide group vanishes, which we attribute to the large distance between the chromophore and the lanthanide, situated on the opposite rims of the calix[4]arene. Both quantum yields and luminescence lifetimes show clear concentration dependence in solution, related to the strong impact of aggregation on the luminescence behaviour. We also evidence the variability in the values of the critical micelle concentration depending on the experimental technique. Such luminescent calix[4]arene platforms accommodating stable lanthanide complexes can be considered valuable building blocks for the design of dual MR/optical imaging probes.

  9. Luminescence properties of the Sm-doped borate glasses

    International Nuclear Information System (INIS)

    Kindrat, I.I.; Padlyak, B.V.; Drzewiecki, A.

    2015-01-01

    The optical absorption and photoluminescence (emission and excitation) spectra as well as decay kinetics of a series of the Sm-doped glasses with Li 2 B 4 O 7 , LiKB 4 O 7 , CaB 4 O 7 , and LiCaBO 3 compositions were investigated and analysed. The Li 2 B 4 O 7 :Sm, LiKB 4 O 7 :Sm, CaB 4 O 7 :Sm, and LiCaBO 3 :Sm glasses of high optical quality have been obtained from the corresponding polycrystalline compounds in the air atmosphere, using a standard glass technology. On the basis of electron paramagnetic resonance (EPR) and optical spectra analysis it was shown that the samarium impurity is incorporated into the glass network as Sm 3+ (4f 5 , 6 H 5/2 ) ions, exclusively. All observed 4f – 4f transitions of the Sm 3+ centres in the optical absorption and luminescence spectra of the investigated glasses are identified. Most intense emission band of the Sm 3+ ions peaked about 598 nm ( 4 G 5/2 → 6 H 7/2 transition) is characterised by a single exponential decay with typical lifetime values, which depend on the basic glass composition as well as concentration and local structure of the Sm 3+ luminescence centres. The quantum efficiency has been evaluated for observed transitions of the Sm 3+ centres using obtained experimental lifetimes and radiative lifetimes calculated by Judd–Ofelt theory. The calculated high quantum efficiencies and measured quantum yields of luminescence show that the investigated borate glasses are perspective luminescence materials. Energy transfer from the Ce 3+ non-controlled impurity and intrinsic luminescence centres to the Sm 3+ centres has been observed. Peculiarities of the Sm 3+ local structure in the network of investigated glasses have been discussed based on the obtained spectroscopic results and structural data. - Highlights: • The Sm-doped Li 2 B 4 O 7 , LiKB 4 O 7 , CaB 4 O 7 , and LiCaBO 3 glasses of high quality were obtained. • EPR, optical absorption and luminescence spectra of Sm 3+ ions in obtained glasses were

  10. Optical stimulated luminescence (OSL) dating

    International Nuclear Information System (INIS)

    Banerjee, D.

    1999-01-01

    Since the pioneering work by Huntley et al. (1985), optical dating is being increasingly recognised as an important technique for establishing a time frame of deposition of sediments (Aitken, 1998). Optical dating differs from thermoluminescence (TL) dating in that visible/infrared light from lasers or LEDs (light-emitting-diodes) is used as a means of stimulation, in contrast to thermal stimulation. It has several advantages over TL dating: (i) the resetting of the OSL (optically stimulated luminescence) clock is more effective than that of TL clock; for sediments transported under water or in other situations where the sediment grains have undergone inhomogeneous bleaching, this property ensures that ages based on optical dating are generally more reliable than TL ages, (ii) the optical dating technique is non-destructive, and multiple readouts of the optical signal is possible; this feature has resulted in the development of single-aliquot and single-grain protocols (Murray and Wintle, 1999; Banerjee et al. 1999), (iii) the sample is not heated as in TL; thus, spurious luminescence is avoided and there is a significant reduction in blackbody radiation. Dating of materials which change phase on heating is also practical, and finally, (iv) thermal quenching of luminescence is negligible, allowing accurate estimation of kinetic parameters using standard techniques and providing access to deep OSL traps. This characteristic may be helpful in extending the limits of optical dating beyond the last 150 ka from a global point of view

  11. An optically stimulated luminescence study of porcelain related to radiation dosimetry

    DEFF Research Database (Denmark)

    Poolton, N.R.J.; Bøtter-Jensen, L.; Jungner, H.

    1995-01-01

    Stokes and anti-Stokes shifted in energy. Glazing is shown in some cases to be considerably more sensitive as a radiation dosemeter than the main porcelain ceramic. By comparison with the properties of artifical phosphors, the principal luminescent matrix is identified as being Al2O3......This article describes the essential features regarding the photo-stimulated luminescence of porcelain: both the main ceramic and glazing materials are studied. In each case, radiation dose dependent signals are observed, superimposed on dose independent luminescence transitions that are both...

  12. Optical and luminescence properties of zinc oxide (Review)

    Science.gov (United States)

    Rodnyi, P. A.; Khodyuk, I. V.

    2011-11-01

    We generalize and systematize basic experimental data on optical and luminescence properties of ZnO single crystals, thin films, powders, ceramics, and nanocrystals. We consider and study mechanisms by which two main emission bands occur, a short-wavelength band near the fundamental absorption edge and a broad long-wavelength band, the maximum of which usually lies in the green spectral range. We determine a relationship between the two luminescence bands and study in detail the possibility of controlling the characteristics of ZnO by varying the maximum position of the short-wavelength band. We show that the optical and luminescence characteristics of ZnO largely depend on the choice of the corresponding impurity and the parameters of the synthesis and subsequent treatment of the sample. Prospects for using zinc oxide as a scintillator material are discussed. Additionally, we consider experimental results that are of principal interest for practice.

  13. Optically stimulated luminescence dosimetry with gypsum wallboard (drywall)

    International Nuclear Information System (INIS)

    Thompson, J. W.; Burdette, K. E.; Inrig, E. L.; Dewitt, R.; Mistry, R.; Rink, W. J.; Boreham, D. R.

    2010-01-01

    Gypsum wallboard (drywall) represents an attractive target for retrospective dosimetry by optically stimulated luminescence (OSL) in the event of a radiological accident or malicious use of nuclear material. In this study, wallboard is shown to display a radiation-induced luminescence signal (RIS) as well as a natural background signal (NS), which is comparable in intensity to the RIS. Excitation and emission spectra show that maximum luminescence intensity is obtained for stimulation with blue light-emitting diodes (470 nm) and for detection in the ultraviolet region (290-370 nm). It is necessary to decrease the optical stimulation power dramatically in order to adequately separate the RIS from the interfering background signal. The necessary protocols are developed for accurately measuring the absorbed dose as low as 500 mGy and demonstrate that the RIS decays logarithmically with storage time, with complete erasure expected within 1-4 d. (authors)

  14. Luminescent screens

    International Nuclear Information System (INIS)

    Lu, C.-I.

    1982-01-01

    Luminescent screens which are useful for such purposes as intensifying screens for radiographs are comprised of a support bearing a layer of finely divided particles of a phosphor dispersed in a cross-linked polymeric matrix formed by heat-curing of a coating composition comprising an unsaturated cross-linkable polymer, a polymerizable acrylic monomer, a thermoplastic polyurethane elastomer, and a heat-activatable polymerization initiator. The phosphor layer includes voids formed by evaporation of an evaporable component which is present in the coating composition from which such layer is formed. (author)

  15. Dependence of the thermal influence on luminescence lifetimes from quartz on the duration of optical stimulation

    International Nuclear Information System (INIS)

    Chithambo, M.L.

    2003-01-01

    Time-resolved luminescence spectra may be measured from quartz at various stages of continuous optical stimulation in order to investigate properties of the spectra associated with the 'fast', 'medium', and 'slow' components of continuous optically stimulated luminescence (OSL). In this work, temperature related changes of luminescence lifetimes and luminescence intensity, both evaluated from time-resolved luminescence spectra recorded in the 'fast' 'medium' and 'slow' component regions of quartz OSL, have been investigated. The luminescence, stimulated at 525 nm, and measured at intervals between 20 deg. C and 200 deg. C reaches maximum intensity at 100 deg. C and decreases thereafter up to 200 deg. C, the maximum temperature of the investigations. Luminescence lifetimes, on the other hand, remain constant within 40±3 μs between 20 deg. C and 100 deg. C and then decrease down to about μs at 200 deg. C. The initial increase of luminescence intensity with temperature between 20 deg. C and 100 deg. C is discussed in terms of thermal assistance to luminescence stimulation. Beyond 100 deg. C, radiative recombination is affected by quenching of luminescence and reduction in luminescence lifetimes. The activation energy for thermal quenching was evaluated to be in the range 0.63±0.07 eV at all stimulation times and that of thermal assistance was evaluated to be about 0.06 eV for the 'fast' and 'medium' component regions and about 0.1 eV for the 'slow' component region of the OSL

  16. Crack luminescence as an innovative method for detection of fatigue damage

    Directory of Open Access Journals (Sweden)

    R. Makris

    2018-04-01

    Full Text Available Conventional non-destructive testing methods for crack detection provide just a snapshot of fatigue crack evolution at a specific location in the moment of examination. The crack luminescence coating realizes a clear visibility of the entire crack formation. The coating consists of two layers with different properties and functions. The bottom layer emits light as fluorescence under UV radiation. The top layer covers the fluorescing one and prevents the emitting of light in case of no damage at the surface. Several different experiments show that due to the sensitive coating even the early stage of crack formation can be detected. That makes crack luminescence helpful for investigating the incipient crack opening behavior. Cracks can be detected and observed during operation of a structure, making it also very interesting for continuous monitoring. Crack luminescence is a passive method and no skilled professionals are necessary to detect cracks, as for conventional methods. The luminescent light is clearly noticeable by unaided eye observations and also by standard camera equipment, which makes automated crack detection possible as well. It is expected that crack luminescence can reduce costs and time for preventive maintenance and inspection.

  17. Origin of green luminescence in hydrothermally grown ZnO single crystals

    Energy Technology Data Exchange (ETDEWEB)

    Čížek, J., E-mail: jakub.cizek@mff.cuni.cz; Hruška, P.; Melikhova, O.; Procházka, I. [Department of Low-Temperature Physics, Charles University in Prague, V Holešovičkách 2, CZ-180 00, Prague 8 (Czech Republic); Valenta, J. [Department of Chemical Physics and Optics, Charles University in Prague, Ke Karlovu 3, CZ-121 16, Prague 2 (Czech Republic); Novotný, M.; Bulíř, J. [Academy of Science of the Czech Republic, Institute of Physics, Na Slovance 2, CZ-182 21 Praha 8 (Czech Republic)

    2015-06-22

    Combining photoluminescence and positron annihilation studies of hydrothermally grown ZnO crystals with stoichiometry varied by controlled annealing enabled us to clarify the origin of green luminescence. It was found that green luminescence in ZnO has multiple origins and consists of a band at 2.3(1) eV due to recombination of electrons of the conduction band by zinc vacancy acceptors coupled with hydrogen and a band at 2.47(2) eV related to oxygen vacancies. The as-grown ZnO crystals contain zinc vacancies associated with hydrogen and exhibit a green luminescence at 2.3(1) eV. Annealing in Zn vapor removed zinc vacancies and introduced oxygen vacancies. This led to disappearance of the green luminescence band at 2.3(1) eV and appearance of a green emission at higher energy of 2.47(2) eV. Moreover, the color of the crystal was changed from colorless to dark red. In contrast, annealing of the as-grown crystal in Cd vapor did not remove zinc vacancies and did not cause any significant change of green luminescence nor change in coloration.

  18. Origin of green luminescence in hydrothermally grown ZnO single crystals

    International Nuclear Information System (INIS)

    Čížek, J.; Hruška, P.; Melikhova, O.; Procházka, I.; Valenta, J.; Novotný, M.; Bulíř, J.

    2015-01-01

    Combining photoluminescence and positron annihilation studies of hydrothermally grown ZnO crystals with stoichiometry varied by controlled annealing enabled us to clarify the origin of green luminescence. It was found that green luminescence in ZnO has multiple origins and consists of a band at 2.3(1) eV due to recombination of electrons of the conduction band by zinc vacancy acceptors coupled with hydrogen and a band at 2.47(2) eV related to oxygen vacancies. The as-grown ZnO crystals contain zinc vacancies associated with hydrogen and exhibit a green luminescence at 2.3(1) eV. Annealing in Zn vapor removed zinc vacancies and introduced oxygen vacancies. This led to disappearance of the green luminescence band at 2.3(1) eV and appearance of a green emission at higher energy of 2.47(2) eV. Moreover, the color of the crystal was changed from colorless to dark red. In contrast, annealing of the as-grown crystal in Cd vapor did not remove zinc vacancies and did not cause any significant change of green luminescence nor change in coloration

  19. Origin of green luminescence in hydrothermally grown ZnO single crystals

    Science.gov (United States)

    Čížek, J.; Valenta, J.; Hruška, P.; Melikhova, O.; Procházka, I.; Novotný, M.; Bulíř, J.

    2015-06-01

    Combining photoluminescence and positron annihilation studies of hydrothermally grown ZnO crystals with stoichiometry varied by controlled annealing enabled us to clarify the origin of green luminescence. It was found that green luminescence in ZnO has multiple origins and consists of a band at 2.3(1) eV due to recombination of electrons of the conduction band by zinc vacancy acceptors coupled with hydrogen and a band at 2.47(2) eV related to oxygen vacancies. The as-grown ZnO crystals contain zinc vacancies associated with hydrogen and exhibit a green luminescence at 2.3(1) eV. Annealing in Zn vapor removed zinc vacancies and introduced oxygen vacancies. This led to disappearance of the green luminescence band at 2.3(1) eV and appearance of a green emission at higher energy of 2.47(2) eV. Moreover, the color of the crystal was changed from colorless to dark red. In contrast, annealing of the as-grown crystal in Cd vapor did not remove zinc vacancies and did not cause any significant change of green luminescence nor change in coloration.

  20. Synthesis and luminescent properties of PEO/lanthanide oxide nanoparticle hybrid films

    Energy Technology Data Exchange (ETDEWEB)

    Goubard, F. [LPPI, Universite de Cergy-Pontoise, 5 Mail Gay-Lussac, Neuville-sur-Oise, 95031 Cergy-Pontoise cedex (France)]. E-mail: fabrice.goubard@u-cergy.fr; Vidal, F. [LPPI, Universite de Cergy-Pontoise, 5 Mail Gay-Lussac, Neuville-sur-Oise, 95031 Cergy-Pontoise cedex (France); Bazzi, R. [LPCML, Universite Lyon 1, 43 Bd. du 11 Novembre 1918, 69622 Villeurbanne (France); Tillement, O. [LPCML, Universite Lyon 1, 43 Bd. du 11 Novembre 1918, 69622 Villeurbanne (France); Nano-H, 23 rue Royal, 69001 Lyon (France); Chevrot, C. [LPPI, Universite de Cergy-Pontoise, 5 Mail Gay-Lussac, Neuville-sur-Oise, 95031 Cergy-Pontoise cedex (France); Teyssie, D. [LPPI, Universite de Cergy-Pontoise, 5 Mail Gay-Lussac, Neuville-sur-Oise, 95031 Cergy-Pontoise cedex (France)

    2007-10-15

    In this study, we investigate the optical properties of lanthanide oxide nanoparticles dispersed in poly(ethylene oxide) (PEO) network as thermally stable polymeric films. The aim of this work is both to keep a good optical transparency in the visible domain and to obtain luminescent materials after incorporation of nanoparticles. For this purpose, we develop luminescent nanocrystals of oxides containing terbium ion as a doping element in Gd{sub 2}O{sub 3}. These sub-5-nm lanthanide oxides nanoparticles have been prepared by direct oxide precipitation in high-boiling polyalcohol solutions and characterized by luminescence spectroscopy. PEO/lanthanide oxide nanohybrid films are prepared by radical polymerization of poly(ethylene glycol) methacrylate after introduction of lanthanide oxide particles. As a first result; the obtained films present interesting luminescence properties with a very low lanthanide oxide content (up to 0.29 wt%). Furthermore, these films are still transparent and keep their original mechanical properties. Prior to describe the specific applications to optical use, we report here the dynamic mechanical analysis (DMA), X-ray diffraction (XRD) analysis, transmission electron microscopy (TEM), and luminescent properties of. nanohybrid films.

  1. High-resolution light microscopy using luminescent nanoparticles.

    Science.gov (United States)

    Ohulchanskyy, Tymish Y; Roy, Indrajit; Yong, Ken-Tye; Pudavar, Haridas E; Prasad, Paras N

    2010-01-01

    This review presents recent progress in the development of the luminescent nanoparticles for confocal and multiphoton microscopy. Four classes of nanomaterials are discussed: (1) silica-based nanoparticles doped with fluorescent molecules, (2) gold nanoparticles, (3) semiconductor nanocrystals (quantum dots/rods), and (4) nanophosphors. Special considerations are given to recently developed imaging nanoprobes, such as (1) organically modified silica (ORMOSIL) nanoparticles doped with two-photon absorbing fluorophores, which exhibit aggregation-enhanced fluorescence (AEF), and (2) nanophosphors (ceramic nanoparticles containing luminescent lanthanoid ions). Advantages and disadvantages of every class of nanomaterials and their specific applications are briefly discussed.

  2. Hydrothermal synthesis, characterization and luminescent ...

    Indian Academy of Sciences (India)

    Home; Journals; Bulletin of Materials Science; Volume 39; Issue 4. Hydrothermal synthesis, characterization and luminescent properties of lanthanide-doped NaLaF 4 nanoparticles. JIGMET LADOL HEENA KHAJURIA SONIKA KHAJURIA ... Keywords. Citric acid; X-ray diffraction; down-conversion emission; energy transfer.

  3. Preparation, characterization and luminescence of nanocrystalline Y2O3:Ho

    International Nuclear Information System (INIS)

    Biljan, Tomislav; Gajovic, Andreja; Meic, Zlatko; Mestrovic, Ernest

    2007-01-01

    Nanocrystalline Y 2 O 3 :Ho was synthesized by solution combustion method with ethylene glycol as fuel. Material was characterized using powder X-ray diffraction and transmission electron microscopy (TEM). X-ray diffraction and TEM showed that the material is nanostructured. Luminescence properties were studied using Raman spectrometers with excitation in near infrared (NIR) and visible regions. The visible and NIR luminescence spectra of nanocrystalline Y 2 O 3 :Ho show some important differences from those of bulk material. The convenience of using Raman instruments for studying luminescence of lanthanide ions is demonstrated

  4. Luminescent properties of LuPO4-Pr and LuPO4-Eu nanoparticles

    International Nuclear Information System (INIS)

    Vistovskyy, V.; Malyi, T.; Vas’kiv, A.; Chylii, M.; Mitina, N.; Zaichenko, A.; Gektin, A.; Voloshinovskii, A.

    2016-01-01

    Spectral-luminescence parameters of LuPO 4 -Eu and LuPO 4 -Pr nanoparticles of different sizes are studied upon excitation by the synchrotron radiation with photon energies 4–40 eV. Influence of the nanoparticle size on Eu 3+ and Pr 3+ impurity luminescence is analyzed for intracenter and recombination excitation. It is shown that the luminescence intensity of impurities in the case of recombination excitation significantly stronger decreases with decreasing of nanoparticle size compared to intracenter excitation. This feature is explained by the influence of thermalization length to nanoparticle size ratio on the recombination luminescence. Electron recombination luminescence inherent for LuPO 4 -Eu nanoparticles shows a weaker dependence on the nanoparticle size than the hole one in LuPO 4 -Pr nanoparticles. The difference between energy states of praseodymium impurity ions in nanoparticles of different sizes is revealed.

  5. Luminescence Properties of Self-Aggregating TbIII-DOTA-Functionalized Calix[4]arenes

    Directory of Open Access Journals (Sweden)

    Florian Mayer

    2018-01-01

    Full Text Available Self-aggregating calix[4]arenes carrying four DOTA ligands on the upper rim for stable complexation of paramagnetic GdIII-ions have already been proposed as MRI probes. In this work, we investigate the luminescence properties of TbIII-DOTA-calix[4]arene-4OPr containing four propyl-groups and compare them with those of the analog substituted with a phthalimide chromophore (TbIII-DOTA-calix[4]arene-3OPr-OPhth. We show that, given its four aromatic rings, the calix[4]arene core acts as an effective sensitizer of Tb-centered luminescence. Substituents on the lower rim can modulate the aggregation behavior, which in turn determines the luminescence properties of the compounds. In solid state, the quantum yield of the phthalimide derivative is almost three times as high as that of the propyl-functionalized analog demonstrating a beneficial role of the chromophore on Tb-luminescence. In solution, however, the effect of the phthalimide group vanishes, which we attribute to the large distance between the chromophore and the lanthanide, situated on the opposite rims of the calix[4]arene. Both quantum yields and luminescence lifetimes show clear concentration dependence in solution, related to the strong impact of aggregation on the luminescence behavior. We also evidence the variability in the values of the critical micelle concentration depending on the experimental technique. Such luminescent calix[4]arene platforms accommodating stable lanthanide complexes can be considered valuable building blocks for the design of dual MR/optical imaging probes.

  6. Circularly Polarized Luminescence from Inorganic Materials: Encapsulating Guest Lanthanide Oxides in Chiral Silica Hosts.

    Science.gov (United States)

    Sugimoto, Masumi; Liu, Xin-Ling; Tsunega, Seiji; Nakajima, Erika; Abe, Shunsuke; Nakashima, Takuya; Kawai, Tsuyoshi; Jin, Ren-Hua

    2018-05-02

    Recently, circularly polarized luminescence (CPL)-active systems have become a very hot and interesting subject in chirality- and optics-related areas. The CPL-active systems are usually available by two approaches: covalently combining a luminescent centre to chiral motif or associating the guest of luminescent probe to a chiral host. However, all the chiral components in CPL materials were organic, although the luminescent components were alternatively organics or inorganics. Herein, the first totally inorganic CPL-active system by "luminescent guest-chiral host" strategy is proposed. Luminescent sub-10 nm lanthanide oxides (Eu 2 O 3 or Tb 2 O 3 ) nanoparticles (guests) were encapsulated into chiral non-helical SiO 2 nanofibres (host) through calcination of chiral SiO 2 hybrid nanofibres, trapping Eu 3+ (or Tb 3+ ). These lanthanide oxides display circular dichroism (CD) optical activity in the ultraviolet wavelength and CPL signals around at 615 nm for Eu 3+ and 545 nm for Tb 3+ . This work has implications for inorganic-based CPL-active systems by incorporation of various luminescent guests within chiral inorganic hosts. © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  7. Construction of order mesoporous (Eu–La)/ZnO composite material and its luminescent characters

    Energy Technology Data Exchange (ETDEWEB)

    Bao, Na; Liu, Yu; Li, Zi-Wei [School of Chemistry & Environmental Engineering, Changchun University of Science and Technology, Changchun 130022 (China); Yu, Hui, E-mail: yh2001101@163.com [School of Chemistry & Environmental Engineering, Changchun University of Science and Technology, Changchun 130022 (China); Bai, Hao-tian [School of Chemistry & Environmental Engineering, Changchun University of Science and Technology, Changchun 130022 (China); Xia, Long, E-mail: xialong_aron@163.com [School of Materials Science and Engineering, Harbin Institute of Technology at Weihai, Weihai 264209 (China); Feng, Da-wei [Changchun University of Science and Technology Science Park, Changchun 130022 (China); Guangdong College of Business and Technology, Zhaoqing 526020 (China); Zhang, Hong-bo; Dong, Xiang-ting; Wang, Tian-yang; Han, Ji; Wu, Rong-yi; Zhang, Qi [School of Chemistry & Environmental Engineering, Changchun University of Science and Technology, Changchun 130022 (China)

    2016-09-15

    For the first time, the order mesoporous zinc oxide was synthesized by a soft template synthesis method. The Eu and La phosphate were introduced into the prepared mesoporous zinc oxide by the high temperature solid phase method, and got the mesoporous rare earth/zinc oxide composite materials. The luminescence characters of the materials were studied. The influences of La to Eu luminescent properties had been studied, and the optimum proportion of Eu and La was discussed. The influences of La and Eu to ZnO luminescence properties were also been studied. La phosphate had the large influence to Eu luminescent. ZnO had a strong emission peak at 469 nm, which overlapped with the {sup 7}F{sub 0}–{sup 5}D{sub 2} transition excitation peak of Eu at 465 nm. It indicated that the effective energy transfer happened between ZnO and Eu, which strongly enhanced the luminescence intensity of Eu. At the same time, the Eu and La phosphates could regulate the defect density of ZnO, which could regulate the luminescent intensity of ZnO, and realized the adjustment of luminescent color between green and red light.

  8. Device and method for luminescence enhancement by resonant energy transfer from an absorptive thin film

    Science.gov (United States)

    Akselrod, Gleb M.; Bawendi, Moungi G.; Bulovic, Vladimir; Tischler, Jonathan R.; Tisdale, William A.; Walker, Brian J.

    2017-12-12

    Disclosed are a device and a method for the design and fabrication of the device for enhancing the brightness of luminescent molecules, nanostructures, and thin films. The device includes a mirror, a dielectric medium or spacer, an absorptive layer, and a luminescent layer. The absorptive layer is a continuous thin film of a strongly absorbing organic or inorganic material. The luminescent layer may be a continuous luminescent thin film or an arrangement of isolated luminescent species, e.g., organic or metal-organic dye molecules, semiconductor quantum dots, or other semiconductor nanostructures, supported on top of the absorptive layer.

  9. Spatially-resolved luminescence spectroscopy of CdSe quantum dots synthesized in ionic liquid crystal matrices

    Energy Technology Data Exchange (ETDEWEB)

    Magaryan, K.A., E-mail: xmagaros@gmail.com [Moscow State Pedagogical University, 29 Malaya Pirogovskaya Str., Moscow 119992 (Russian Federation); Mikhailov, M.A. [Moscow State Pedagogical University, 29 Malaya Pirogovskaya Str., Moscow 119992 (Russian Federation); Karimullin, K.R. [Moscow State Pedagogical University, 29 Malaya Pirogovskaya Str., Moscow 119992 (Russian Federation); Institute for Spectroscopy of RAS, 5 Fizicheskaya Str., Troitsk, Moscow 142190 (Russian Federation); E.K. Zavoyski Kazan Physical-Technical Institute of RAS, 10/7 Sibirski trakt Str., Kazan 420029 (Russian Federation); Knyazev, M.V.; Eremchev, I.Y. [Institute for Spectroscopy of RAS, 5 Fizicheskaya Str., Troitsk, Moscow 142190 (Russian Federation); Naumov, A.V. [Moscow State Pedagogical University, 29 Malaya Pirogovskaya Str., Moscow 119992 (Russian Federation); Institute for Spectroscopy of RAS, 5 Fizicheskaya Str., Troitsk, Moscow 142190 (Russian Federation); Vasilieva, I.A. [Moscow State Pedagogical University, 29 Malaya Pirogovskaya Str., Moscow 119992 (Russian Federation); Klimusheva, G.V. [Institute of Physics, NAS of Ukraine, 46 Prospect Nauki, Kiev 03028 (Ukraine)

    2016-01-15

    The paper is devoted to investigation of luminescence properties of new quantum dot (QD)-doped materials. We studied CdSe QDs (1.8 nm and 2.3 nm) grown inside of a liquid crystalline cadmium alcanoate matrix. Temperature dependence of parameters of fluorescence spectra obtained in a wide temperature range using epi-luminescence microscopy technique was analyzed. Spatially-resolved luminescence images were measured for the areas of the samples of 150×150 µm{sup 2}. Strong correlation between fluorescence spectra and sample structure was observed. - Highlights: • Glassy matrix with CdSe quantum dots inside fabricated in liquid crystalline mesophase. • Study of luminescence properties in a wide range of low temperatures. • Strong dependence of the luminescence spectra on spatial inhomogeneities. • Spatially-resolved luminescence imaging of quantum dots in liquid crystalline matrix.

  10. Spatially-resolved luminescence spectroscopy of CdSe quantum dots synthesized in ionic liquid crystal matrices

    International Nuclear Information System (INIS)

    Magaryan, K.A.; Mikhailov, M.A.; Karimullin, K.R.; Knyazev, M.V.; Eremchev, I.Y.; Naumov, A.V.; Vasilieva, I.A.; Klimusheva, G.V.

    2016-01-01

    The paper is devoted to investigation of luminescence properties of new quantum dot (QD)-doped materials. We studied CdSe QDs (1.8 nm and 2.3 nm) grown inside of a liquid crystalline cadmium alcanoate matrix. Temperature dependence of parameters of fluorescence spectra obtained in a wide temperature range using epi-luminescence microscopy technique was analyzed. Spatially-resolved luminescence images were measured for the areas of the samples of 150×150 µm 2 . Strong correlation between fluorescence spectra and sample structure was observed. - Highlights: • Glassy matrix with CdSe quantum dots inside fabricated in liquid crystalline mesophase. • Study of luminescence properties in a wide range of low temperatures. • Strong dependence of the luminescence spectra on spatial inhomogeneities. • Spatially-resolved luminescence imaging of quantum dots in liquid crystalline matrix.

  11. X-ray excited luminescence of polystyrene composites loaded with SrF{sub 2} nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    Demkiv, T.M.; Halyatkin, O.O.; Vistovskyy, V.V. [Ivan Franko National University of Lviv, 8a Kyryla i Mefodiya St., 79005 Lviv (Ukraine); Hevyk, V.B. [Ivano-Frankivsk National Technical University of Oil and Gas, 15 Karpatska St., 76019 Ivano-Frankivsk (Ukraine); Yakibchuk, P.M. [Ivan Franko National University of Lviv, 8a Kyryla i Mefodiya St., 79005 Lviv (Ukraine); Gektin, A.V. [Institute for Scintillation Materials, NAS of Ukraine, 60 Lenina Ave, 61001 Kharkiv (Ukraine); Voloshinovskii, A.S. [Ivan Franko National University of Lviv, 8a Kyryla i Mefodiya St., 79005 Lviv (Ukraine)

    2017-03-01

    The polystyrene film nanocomposites of 0.3 mm thickness with embedded SrF{sub 2} nanoparticles up to 40 wt% have been synthesized. The luminescent and kinetic properties of the polystyrene composites with embedded SrF{sub 2} nanoparticles upon the pulse X-ray excitation have been investigated. The luminescence intensity of the pure polystyrene scintillator film significantly increases when it is loaded with the inorganic SrF{sub 2} nanoparticles. The film nanocomposites show fast (∼2.8 ns) and slow (∼700 ns) luminescence decay components typical for a luminescence of polystyrene activators (p-Terphenyl and POPOP) and SrF{sub 2} nanoparticles, respectively. It is revealed that the fast decay luminescence component of the polystyrene composites is caused by the excitation of polystyrene by the photoelectrons escaped from the nanoparticles due to photoeffect, and the slow component is caused by reabsorption of the self-trapped exciton luminescence of SrF{sub 2} nanoparticles by polystyrene.

  12. Application of pulse spectro- zonal luminescent method for the rapid method of material analysis

    International Nuclear Information System (INIS)

    Lisitsin, V.M.; Oleshko, V.I.; Yakovlev, A.N.

    2004-01-01

    Full text: The scope of luminescent methods of the analysis covers enough a big around of substances as the luminescence can be excited in overwhelming majority of nonmetals. Analytical opportunities of luminescent methods can be essentially expanded by use of pulse excitation and registration of spectra of a luminescence with the time resolved methods. The most perspective method is to use pulses of high-current electron beams with the nanosecond duration for excitation from the following reasons: excitation is carried out ionizing, deeply enough by a penetrating radiation; the pulse of radiation has high capacity, up to 10 8 W, but energy no more than 1 J; the pulse of radiation has the nanosecond duration. Electrons with energy in 300-400 keV will penetrate on depth into some tenth shares of mm, i.e. they create volumetric excitation of a sample. Therefore the luminescence raised by an electronic beam has the information about volumetric properties of substance. High density of excitation allow to find out and study the centers (defects) having a small yield of a luminescence, to analyze the weakly luminescent objects. Occurrence of the new effects is possible useful to analyze of materials. There is an opportunity of reception of the information from change of spectral structure of a luminescence during the time after the ending of a pulse of excitation and kinetic characteristics of attenuation of luminescence. The matter is the energy of radiation is absorbed mainly by a matrix, then electronic excitations one is transferred the centers of a luminescence (defects) of a lattice. Therefore during the time after creation electronic excitations the spectrum of a luminescence can repeatedly change, transferring the information on the centers (defects) which are the most effective radiators at present time. Hence, the study of change of spectra of radiation during the time allows providing an additional way of discrimination of the information on the centers of a

  13. Redox-induced reversible luminescence switching of cerium-doped upconversion nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    Huang, Yanan [College of Sciences, Shanghai University, Shanghai 200444 (China); International Laboratory for Adaptive Bio-nanotechnology, Suzhou Institute of Nano-tech and Nano-bionics (SINANO), Chinese Academy of Science, Suzhou 215123 (China); Xiao, Qingbo, E-mail: qbxiao2011@sinano.ac.cn [International Laboratory for Adaptive Bio-nanotechnology, Suzhou Institute of Nano-tech and Nano-bionics (SINANO), Chinese Academy of Science, Suzhou 215123 (China); Wang, Jian [College of Sciences, Shanghai University, Shanghai 200444 (China); International Laboratory for Adaptive Bio-nanotechnology, Suzhou Institute of Nano-tech and Nano-bionics (SINANO), Chinese Academy of Science, Suzhou 215123 (China); Xi, Yonglan [Laboratory for Agricultural Wastes Treatment and Recycling Institute of Agricultural Resources and Environment, Jiangsu Academy of Agricultural Science, Nanjing 210014 (China); Li, Fujin [International Laboratory for Adaptive Bio-nanotechnology, Suzhou Institute of Nano-tech and Nano-bionics (SINANO), Chinese Academy of Science, Suzhou 215123 (China); Feng, Yamin [College of Sciences, Shanghai University, Shanghai 200444 (China); International Laboratory for Adaptive Bio-nanotechnology, Suzhou Institute of Nano-tech and Nano-bionics (SINANO), Chinese Academy of Science, Suzhou 215123 (China); Shi, Liyi [College of Sciences, Shanghai University, Shanghai 200444 (China); Lin, Hongzhen, E-mail: hzlin2010@sinano.ac.cn [International Laboratory for Adaptive Bio-nanotechnology, Suzhou Institute of Nano-tech and Nano-bionics (SINANO), Chinese Academy of Science, Suzhou 215123 (China)

    2016-05-15

    Smart upconversion nanophosphors (UCNPs) that can be reversibly switched between two or more luminescent states by certain external stimuli have attracted considerable attention due to their great potential in biological applications. Here we report for the first time a type of redox-switchable UCNPs by codoping NaGdF{sub 4}:Yb/Er nanorods with the redox-active Ce{sup 3+}/Ce{sup 4+} ion pairs. A reversible switching of their UC luminescence intensity was observed upon the variation of the surrounding redox environments. We show solid proof that the luminescence switching is caused by the tailoring of the NaGdF{sub 4} host crystal structure in response to changing redox state of the codoped cerium ions. A proof-of-concept example is further demonstrated by using these UCNPs for probing the dynamical variation of redox environments in biological tissues. - Highlights: • Synthesis of upconversion nanoparticles doped with Ce{sup 3+}/Ce{sup 4+} ions. • The precise and reversible modification of crystal structure by redox reactions. • Tuning the upconversion luminescence by tailoring the crystal structure.

  14. Mechanism of band-edge luminescence in cuprous iodide single crystals

    International Nuclear Information System (INIS)

    Gao, Pan; Gu, Mu; Liu, Xi; Liu, Bo; Zheng, Yan-Qing; Shi, Er-Wei; Shi, Jun-Yan; Zhang, Guo-bin

    2014-01-01

    Highlights: • The luminescence properties of CuI crystals are influenced by the quality of the as-grown crystals. • The emission peaks of free-exciton and bound-exciton are observed in the CuI single crystals. • The ultrafast component luminescence is warranted to the donor-acceptor pair recombination. • The exciton absorption and electron excitation multiplication processes were observed in CuI. - Abstract: The photoluminescence spectra of CuI crystals using synchrotron radiation as an excitation light source were obtained at 60 K. The emission peaks at 405, 415, 420 and 443 nm were observed. The possible origins of these peaks were discussed by the temperature dependence of luminescence spectra for CuI material. Meanwhile, the photoluminescence spectra of CuI powder with different excitation intensity were measured and the ultrafast luminescence component of CuI crystals was warranted to be attributed to the recombination of donor acceptor pair. Furthermore, the excitation process was studied by measuring the photoluminescence excitation spectra of CuI crystals and powder

  15. Raman scattering and luminescence of high-Tc superconducting oxides

    International Nuclear Information System (INIS)

    Eremenko, V.V.; Gnezdilov, V.P.; Fomin, V.I.; Fugol', I.Ya.; Samovarov, V.N.

    1989-01-01

    Raman and luminescence spectra of high-T c superconducting oxides are summarized, mainly YBa 2 Cu 3 O 7-σ and partly La 2-x Ba x CuO 4-σ . In raman spectra we succeeded to distinguish electron scattering to define the energy gap Δ in the superconducting state. The luminescence spectra are due to the emission of oxygen and interaction with conduction electrons. 70 refs.; 13 figs

  16. Luminescence properties of the Sm-doped borate glasses

    Energy Technology Data Exchange (ETDEWEB)

    Kindrat, I.I. [University of Zielona Góra, Institute of Physics, Division of Spectroscopy of Functional Materials, 4a Szafrana Street, 65-516 Zielona Góra (Poland); Padlyak, B.V., E-mail: B.Padlyak@if.uz.zgora.pl [University of Zielona Góra, Institute of Physics, Division of Spectroscopy of Functional Materials, 4a Szafrana Street, 65-516 Zielona Góra (Poland); Vlokh Institute of Physical Optics, 23 Dragomanov Street, 79-005 Lviv (Ukraine); Drzewiecki, A. [University of Zielona Góra, Institute of Physics, Division of Spectroscopy of Functional Materials, 4a Szafrana Street, 65-516 Zielona Góra (Poland)

    2015-10-15

    The optical absorption and photoluminescence (emission and excitation) spectra as well as decay kinetics of a series of the Sm-doped glasses with Li{sub 2}B{sub 4}O{sub 7}, LiKB{sub 4}O{sub 7}, CaB{sub 4}O{sub 7}, and LiCaBO{sub 3} compositions were investigated and analysed. The Li{sub 2}B{sub 4}O{sub 7}:Sm, LiKB{sub 4}O{sub 7}:Sm, CaB{sub 4}O{sub 7}:Sm, and LiCaBO{sub 3}:Sm glasses of high optical quality have been obtained from the corresponding polycrystalline compounds in the air atmosphere, using a standard glass technology. On the basis of electron paramagnetic resonance (EPR) and optical spectra analysis it was shown that the samarium impurity is incorporated into the glass network as Sm{sup 3+} (4f{sup 5}, {sup 6}H{sub 5/2}) ions, exclusively. All observed 4f – 4f transitions of the Sm{sup 3+} centres in the optical absorption and luminescence spectra of the investigated glasses are identified. Most intense emission band of the Sm{sup 3+} ions peaked about 598 nm ({sup 4}G{sub 5/2} → {sup 6}H{sub 7/2} transition) is characterised by a single exponential decay with typical lifetime values, which depend on the basic glass composition as well as concentration and local structure of the Sm{sup 3+} luminescence centres. The quantum efficiency has been evaluated for observed transitions of the Sm{sup 3+} centres using obtained experimental lifetimes and radiative lifetimes calculated by Judd–Ofelt theory. The calculated high quantum efficiencies and measured quantum yields of luminescence show that the investigated borate glasses are perspective luminescence materials. Energy transfer from the Ce{sup 3+} non-controlled impurity and intrinsic luminescence centres to the Sm{sup 3+} centres has been observed. Peculiarities of the Sm{sup 3+} local structure in the network of investigated glasses have been discussed based on the obtained spectroscopic results and structural data. - Highlights: • The Sm-doped Li{sub 2}B{sub 4}O{sub 7}, LiKB{sub 4}O{sub 7}, Ca

  17. X-Ray Absorption Near-Edge Structure (XANES) of Calcium L3,2 Edges of Various Calcium Compounds and X-Ray Excited Optical Luminescence (XEOL) Studies of Luminescent Calcium Compounds

    International Nuclear Information System (INIS)

    Ko, J. Y. Peter; Zhou Xingtai; Sham, T.-K.; Heigl, Franziskus; Regier, Tom; Blyth, Robert

    2007-01-01

    X-ray absorption at calcium L3,2 edges of various calcium compounds were measured using a high resolution Spherical Grating Monochromator (SGM) at the Canadian Light Source (CLS). We observe that each compound has its unique fine structure of L3,2 edges. This uniqueness is due to differences in local structure of compounds. We also performed (X-ray Excited Optical Luminescence) XEOL of selected luminescent calcium compounds to investigate their optical properties. XEOL is a photon-in-photon-out technique in which the optical luminescence that is excited by tunable x-rays from a synchrotron light source is monitored. Depending on excitation energy of the x-ray, relative intensities of luminescence peaks vary. Recent findings of the results will be presented here

  18. Luminescence and scintillation properties of LuPO4-Ce nanoparticles

    International Nuclear Information System (INIS)

    Vistovskyy, V.; Malyy, T.; Pushak, A.; Vas’kiv, A.; Shapoval, A.; Mitina, N.; Gektin, A.; Zaichenko, A.; Voloshinovskii, A.

    2014-01-01

    Study of the spectral-luminescence parameters of LuPO 4 -Ce nanoparticles upon the excitation by X-ray quanta and synchrotron radiation with photon energies of 4–25 eV was performed. Nanoparticles with mean size about a=35 nm and nanoparticles with size less than 12 nm reveal the different structures of cerium centers. Luminescence efficiency of LuPO 4 -Ce nanoparticles of a 4 -Ce nanoparticles studied using synchrotron and X-ray excitation. • Different structure of Ce 3+ -centers has been revealed for LuPO 4 -Ce nanoparticles. • Luminescence of LuPO 4 -Ce with size less than 12 nm is strongly quenched upon the X-ray excitation

  19. STUDIES ON BIOLUMINESCENCE : XVII. FLUORESCENCE AND INHIBITION OF LUMINESCENCE IN CTENOPHORES BY ULTRA-VIOLET LIGHT.

    Science.gov (United States)

    Harvey, E N

    1925-01-20

    1. Small dumps of the luminous cells of Mnemiopsis cannot readily be stimulated mechanically but will luminesce on treatment with saponin solution. Larger groups of luminous cells (such as are connected with two paddle plates) luminesce on mechanical stimulation. This suggests that mechanical stimulation to luminesce occurs chiefly through a nerve mechanism which has been broken up in the small dumps of luminous tissue. 2. The smallest bits of luminous tissue, even cells freed from the animal by agitation, that will pass through filter paper, lose their power to luminesce in daylight and regain it (at least partially) in the dark. 3. Luminescence of the whole animal and of individual cells is suppressed by near ultra-violet light (without visible light). 4. Inhibition in ultra-violet light is not due to stimulation (by the ultra-violet light) of the animal to luminesce, thereby using up the store of photogenic material. 5. Animals stimulated mechanically several times and placed in ultra-violet light show a luminescence along the meridians in the same positions as the luminescence that appears on stimulation. This luminescence in the ultra-violet or "tonic luminescence," is not obtained with light adapted ctenophores and is interpreted to be a fluorescence of the product of oxidation of the photogenic material. 6. Marked fluorescence of the luminous organ of the glowworm (Photuris) and of the luminous slime of Chatopterus may be observed in ultra-violet but no marked fluorescence of the luminous substances of Cypridina is apparent. 7. Evidence is accumulating to show a close relation between fluorescent and chemiluminescent substances in animals, similar to that described for unsaturated silicon compounds and the Grignard reagents.

  20. Delayed luminescence in a multiparameter approach to evaluation and reduction of radiobiological risks

    Science.gov (United States)

    Grasso, Rosaria; Cammarata, Francesco Paolo; Minafra, Luigi; Marchese, Valentina; Russo, Giorgio; Manti, Lorenzo; Musumeci, Francesco; Scordino, Agata

    2017-07-01

    In the framework of the research project ETHICS "Pre-clinical experimental and theoretical studies to improve treatment and protection by charged particles" funded by the National Nuclear Physics Institute, Italy, we studied the phenomenon called delayed luminescence emitted by non-tumorigenic breast epithelial MCF10A cell line after proton irradiation at different doses (0.5, 2, 6, 9 Gy). The aim is to found possible correlations between delayed luminescence and in vitro damaging induced by ion irradiation. The first results of this research show that the delayed luminescence kinetics is proton dose dependent. An interesting correlation between delayed luminescence and clonogenic potential was observed.

  1. Afterglow luminescence in sol-gel/Pechini grown oxide materials: persistence or phosphorescence process? (Conference Presentation)

    Science.gov (United States)

    Sontakke, Atul; Ferrier, Alban; Viana, Bruno

    2017-03-01

    Persistent luminescence and phosphorescence, both yields afterglow luminescence, but are completely different mechanisms. Persistent luminescence involves a slow thermal release of trapped electrons stored in defect states, whereas the phosphorescence is caused due to triplet to singlet transition [1,2]. Many persistent luminescence phosphors are based on oxide inorganic hosts, and exhibit long afterglow luminescence after ceasing the excitation. We observed intense and long afterglow luminescence in sol-gel/pechini grown inorganic oxides, and as a first interpretation thought to be due to persistence mechanism. However, some of these materials do not exhibit defect trap centers, and a detailed investigation suggested it is due to phosphorescence, but not the persistence. Phosphorescence is not common in inorganic solids, and that too at room temperature, and therefore usually misinterpreted as persistence luminescence [3]. Here we present a detailed methodology to distinguish phosphorescence from persistence luminescence in inorganic solids, and the process to harvest highly efficient long phosphorescence afterglow at room temperature. 1. Jian Xu, Setsuhisa Tanabe, Atul D. Sontakke, Jumpei Ueda, Appl. Phys. Lett. 107, 081903 (2015) 2. Sebastian Reineke, Marc A. Baldo, Scientific Reports, 4, 3797 (2014) 3. Pengchong Xue, Panpan Wang, Peng Chen, Boqi Yao, Peng Gong, Jiabao Sun, Zhenqi Zhang, Ran Lu, Chem. Sci. (2016) DOI: 10.1039/C5SC03739E

  2. Plasmon-enhanced luminescence of Sm complex using silver nanoparticles in Polyvinyl Alcohol

    Energy Technology Data Exchange (ETDEWEB)

    Kaur, Gagandeep; Verma, R.K.; Rai, D.K. [Laser and Spectroscopy Laboratory, Department of Physics, Banaras Hindu University, India 221005 (India); Rai, S.B., E-mail: sbrai49@yahoo.co.in [Laser and Spectroscopy Laboratory, Department of Physics, Banaras Hindu University, India 221005 (India)

    2012-07-15

    Silver (Ag) nanoparticles (NPs) were prepared by laser ablation in water with an aim to enhance the luminescence of rare earth coordinated complex in polymer host. A fixed concentration of the complex containing Samarium (Sm), Salicylic acid (Sal) and 1, 10-phenanthroline (Phen) were combined with different concentrations of silver NPs in PolyVinyl Alcohol at room temperature. Absorption spectrum and XRD patterns of the sample show that the Sm(Sal){sub 3}Phen complex is accompanied by Ag NPs. The luminescence from the complex was recorded in the presence and absence of Ag NPs using two different excitation wavelengths viz. 400 and 355 nm. Of these, 400 nm radiation falls in the surface plasmon resonance of Ag NPs. It was found that the Ag NPs led to a significant enhancement in luminescence of the complex. Surprisingly, a high concentration of Ag NPs tends to quench the luminescence. - Highlights: Black-Right-Pointing-Pointer Sm complex with Ag nanoparticles in PVA was prepared at room temperature. Black-Right-Pointing-Pointer UV-vis absorption and XRD confirms the presence of Sm complex and Ag NPs. Black-Right-Pointing-Pointer Enhancement in luminescence of complex was observed with Ag NPs. Black-Right-Pointing-Pointer Coupling between radiative transitions of Sm and SPR of NPs enhances the emission. Black-Right-Pointing-Pointer The higher concentration of Ag NPs quenches the luminescence of the complex.

  3. Luminescent Metal Nanoclusters for Potential Chemosensor Applications

    Directory of Open Access Journals (Sweden)

    Muthaiah Shellaiah

    2017-12-01

    Full Text Available Studies of metal nanocluster (M-NCs-based sensors for specific analyte detection have achieved significant progress in recent decades. Ultra-small-size (<2 nm M-NCs consist of several to a few hundred metal atoms and exhibit extraordinary physical and chemical properties. Similar to organic molecules, M-NCs display absorption and emission properties via electronic transitions between energy levels upon interaction with light. As such, researchers tend to apply M-NCs in diverse fields, such as in chemosensors, biological imaging, catalysis, and environmental and electronic devices. Chemo- and bio-sensory uses have been extensively explored with luminescent NCs of Au, Ag, Cu, and Pt as potential sensory materials. Luminescent bi-metallic NCs, such as Au-Ag, Au-Cu, Au-Pd, and Au-Pt have also been used as probes in chemosensory investigations. Both metallic and bi-metallic NCs have been utilized to detect various analytes, such as metal ions, anions, biomolecules, proteins, acidity or alkalinity of a solution (pH, and nucleic acids, at diverse detection ranges and limits. In this review, we have summarized the chemosensory applications of luminescent M-NCs and bi-metallic NCs.

  4. Direct and indirect dating of gypsum occurrences in deserts using luminescence methods

    International Nuclear Information System (INIS)

    Nagar, Y.C.; Juyal, N.; Singhyi, A.K.; Kocurek, G.; Wadhawan, S.K.

    2005-01-01

    In the present study we have made an attempt to directly date gypsum or provide indirect age estimate for gypsum formation through dating the associated sediments (quartz) using the luminescence dating technique. In the direct dating of gypsum, we explored the Optically Stimulated Luminescence (OSL) and Thermally Stimulated Luminescence (TL) behaviour of gypsum. The associated sediments (indirect dating) were dated using the traces of quartz extract from gypsum (concentration 0.1% ) and the underlying and overlying quartz sand in playa

  5. Tooth surface loss, prevalence and associated risk factors among 12-14 years school children in Khartoum State, Sudan.

    Science.gov (United States)

    Sanhouri, N M; Ziada, H M; Ahmed, G I; Kamis, A H

    2010-12-01

    Investigate Tooth Surface Loss TSL, among 12-14 years school children in Khartoum State, Sudan; evaluate pattern, severity and determine relationship between TSL, dietary habits and socio-economical status. Cross sectional survey among primary public and private schools. Cluster sample of 1,138 12 to 14-year old students from both public and private school. Mild and moderate TSL was measured on buccal, lingual/palatal surfaces of maxillary and mandibular incisors and canines and occlusal, buccal, lingual/palatal surfaces of maxillary and mandibular premolars and molars. Surfaces scored according to criterion described by the National Survey of Child Dental Health. The prevalence of TSL was found to be 74%. Mild and moderate TSL was detected on palatal surfaces of maxillary central incisors followed by occlusal surfaces of mandibular molars. TSL into the pulp was not detected. A high prevalence of 74% was found with mild and moderate TSL with no pulpal involvement. There was an association between consumption of erosive foods and the prevalence of TSL. Socio-economic status and gender did not present significant differences.

  6. Anomalous enhancement of nanodiamond luminescence upon heating

    Science.gov (United States)

    Khomich, A. A.; Kudryavtsev, O. S.; Dolenko, T. A.; Shiryaev, A. A.; Fisenko, A. V.; Konov, V. I.; Vlasov, I. I.

    2017-02-01

    Characteristic photoluminescence (PL) of nanodiamonds (ND) of different origin (detonation, HPHT, extracted from meteorite) was studied in situ at high temperatures in the range 20-450 °C. Luminescence was excited using 473 nm laser and recorded in the range 500-800 nm. In contrast to decrease of point defect PL in bulk diamond with temperature, we found that the ND luminescence related to ND surface defects increases almost an order of magnitude upon heating to 200-250 °C. The observed effect reveals that water adsorbed on ND surfaces efficiently quenches PL; water desorption on heating leads to dramatic increase of the radiative de-excitation.

  7. Dosimetry based on thermally and optically stimulated luminescence

    International Nuclear Information System (INIS)

    Agersnap Larsen, Niels

    1999-01-01

    Thermally Stimulated Luminescence (TL) and Optically Stimulated Luminescence (OSL) properties of quartz and α-Al 2 O 3 have been investigated. Anneling-induced OSL and TL sensitivity changes in quartz has been investigated by experiments and modelling. This study does not support a pre-dose effect to account for the observed annealing-induced sensitivity change. The experimental data indicates a more simple mechanism that involves alteration of the concentration of the defect centers. Results from modelling of removal or creation of defect centers comparing well with experimentally obtained data. Thermal quenching of luminescence for the main emission center, the F-center, in α-Al 2 O 3 :C has been investigated by analysing TL curves obtained at different heating rates. The thermal quenching dependence of luminescence is found to follow the classical Mott-Seitz expression. Basic investigations of OSL properties of αAl 2 O 3 :C, including: the thermal depth of the OSL traps, the temperature dependence of OSL, and the OSL stimulation spectra. Simultaneous measurements of TL and thermally stimulated conductivity (TSC) are presented for γ-irradiated αAl 2 O 3 :C. Activation energy analysis of the data reveals a superposition of several first-order TL and TSC peaks caused by release of charge carriers from a distribution of trapping states. Furthermore a description of an experimental method developed to determine the sign of the thermally released charge carriers has been presented. (au)

  8. Luminescent Lanthanide Reporters for High-Sensitivity Novel Bioassays

    Energy Technology Data Exchange (ETDEWEB)

    Anstey, Mitchell R. [Sandia National Lab. (SNL-CA), Livermore, CA (United States); Fruetel, Julia A. [Sandia National Lab. (SNL-CA), Livermore, CA (United States); Foster, Michael E. [Sandia National Lab. (SNL-CA), Livermore, CA (United States); Hayden, Carl C. [Sandia National Lab. (SNL-CA), Livermore, CA (United States); Buckley, Heather L. [Sandia National Lab. (SNL-CA), Livermore, CA (United States); Arnold, John [Sandia National Lab. (SNL-CA), Livermore, CA (United States)

    2013-09-01

    Biological imaging and assay technologies rely on fluorescent organic dyes as reporters for a number of interesting targets and processes. However, limitations of organic dyes such as small Stokes shifts, spectral overlap of emission signals with native biological fluorescence background, and photobleaching have all inhibited the development of highly sensitive assays. To overcome the limitations of organic dyes for bioassays, we propose to develop lanthanide-based luminescent dyes and demonstrate them for molecular reporting applications. This relatively new family of dyes was selected for their attractive spectral and chemical properties. Luminescence is imparted by the lanthanide atom and allows for relatively simple chemical structures that can be tailored to the application. The photophysical properties offer unique features such as narrow and non-overlapping emission bands, long luminescent lifetimes, and long wavelength emission, which enable significant sensitivity improvements over organic dyes through spectral and temporal gating of the luminescent signal.Growth in this field has been hindered due to the necessary advanced synthetic chemistry techniques and access to experts in biological assay development. Our strategy for the development of a new lanthanide-based fluorescent reporter system is based on chelation of the lanthanide metal center using absorbing chromophores. Our first strategy involves "Click" chemistry to develop 3-fold symmetric chelators and the other involves use of a new class of tetrapyrrole ligands called corroles. This two-pronged approach is geared towards the optimization of chromophores to enhance light output.

  9. Luminescent properties of Al2O3: Tb powders

    International Nuclear Information System (INIS)

    Esparza G, A.E.; Garcia, M.; Falcony, C.; Azorin N, J.

    2000-01-01

    In this work the photo luminescent and cathode luminescent characteristics of aluminium oxide (Al 2 O 3 ) powders impurified with terbium (Tb) were studied for their use in dosimetry. The optical, structural, morphological characteristics of the powders as function of variation in the impurity concentration and the annealing temperature will be presented. As regards the optical properties of powders (photoluminescence and cathode luminescence) it was observed a characteristic emission associated with radiative transitions between electron energy levels of terbium, the spectra associated with this emission consists of several peaks associated with such transitions. In the structural and morphological characterization (X-ray diffraction and scanning electron microscopy) it was appreciated that in accordance the annealing temperature of powders is augmented it is evident the apparition of certain crystalline phases. The results show that this is a promissory material for radiation dosimetry. (Author)

  10. Fiber-coupled Luminescence Dosimetry in Therapeutic and Diagnostic Radiology

    DEFF Research Database (Denmark)

    Andersen, Claus Erik

    2011-01-01

    . Some crystalline phosphors, such as carbon-doped aluminium oxide (Al2O3:C) have the ability to store charge produced in the crystal during irradiation. The stored charge may later be released by fiber-guided laser light under emission of so-called optically stimulated luminescence (OSL). The OSL signal......Fiber-coupled luminescence dosimetry is an emerging technology with several potentially attractive features of relevance for uses in therapeutic and diagnostic radiology: direct water equivalence (i.e. no significant perturbation of the radiation field in a water phantom or a patient), sub......-mm detector size, high dynamic range (below a mGy to several Gy), microsecond time resolution, and absence of electrical wires or other electronics in the dosimeter probe head. Fiber-coupled luminescence dosimetry systems typically consist of one or more small samples of phosphor, e.g. a mg of plastic...

  11. Performance of a novel multiple-signal luminescence sediment tracing method

    Science.gov (United States)

    Reimann, Tony

    2014-05-01

    Optically Stimulated Luminescence (OSL) is commonly used for dating sediments. Luminescence signals build up due to exposure of mineral grains to natural ionizing radiation, and are reset when these grains are exposed to (sun)light during sediment transport and deposition. Generally, luminescence signals can be read in two ways, potentially providing information on the burial history (dating) or the transport history (sediment tracing) of mineral grains. In this study we use a novel luminescence measurement procedure (Reimann et al., submitted) that simultaneously monitors six different luminescence signals from the same sub-sample (aliquot) to infer the transport history of sand grains. Daylight exposure experiments reveal that each of these six signals resets (bleaches) at a different rate, thus allowing to trace the bleaching history of the sediment in six different observation windows. To test the feasibility of luminescence sediment tracing in shallow-marine coastal settings we took eight sediment samples from the pilot mega-nourishment Zandmotor in Kijkduin (South-Holland). This site provides relatively controlled conditions as the morphological evolution of this nourishment is densely monitored (Stive et al., 2013). After sampling the original nourishment source we took samples along the seaward facing contour of the spit that was formed from August 2011 (start of nourishment) to June 2012 (sampling). It is presumed that these samples originate from the source and were transported and deposited within the first year after construction. The measured luminescence of a sediment sample was interpolated onto the daylight bleaching curve of each signal to assign the Equivalent Exposure Time (EET) to a sample. The EET is a quantitative measure of the full daylight equivalent a sample was exposed to during sediment transport, i.e. the higher the EET the longer the sample has been transported or the more efficient it has been exposed to day-light during sediment

  12. Piezoelectrically-induced stress-luminescence phenomenon in CaAl{sub 2}O{sub 4}:Eu{sup 2+}

    Energy Technology Data Exchange (ETDEWEB)

    Wei, Yongbin [Department of Physics, Zhejiang Normal University, Jinhua 321004 (China); Wu, Zheng, E-mail: wuzheng@zjnu.cn [College of Geography and Environmental Sciences, Zhejiang Normal University, Jinhua 321004 (China); Jia, Yanmin, E-mail: ymjia@zjnu.edu.cn [Department of Physics, Zhejiang Normal University, Jinhua 321004 (China); Liu, Yongsheng [Department of Physics, Shanghai University of Electric Power, Shanghai 200090 (China)

    2015-10-15

    Piezoelectrically-induced stress-luminescence in the CaAl{sub 2}O{sub 4}:Eu{sup 2+} was investigated. Blue light that was visible to the naked eye could be observed in the dark when a pulse force of ∼7.7 kN was applied to the sample. The intensity of the stress-luminescence strongly depended on the magnitude of the applied force during a pulse cycle. The intensity decreased with repetitive application of pulse stress and was completely recovered after irradiation with ultraviolet light. It is suggested that the stress-luminescence effect in CaAl{sub 2}O{sub 4}:Eu{sup 2+} arises from the piezoelectrically-induced de-trapping of the charge carriers. A CaAl{sub 2}O{sub 4}:Eu{sup 2+} ceramic that exhibits a stress-luminescence effect has potential applications in smart stress optically-sensing devices. - Highlights: • The strong induced stress-luminescence in CaAl{sub 2}O{sub 4}:Eu{sup 2+} was observed. • The stress-luminescent intensity strongly depends on the magnitude of force. • The stress-luminescence could be completely recovered after the UV irradiation. • The strong stress-luminescent effect is potential in stress-light sensors.

  13. Cone Beam X-Ray Luminescence Tomography Imaging Based on KA-FEM Method for Small Animals.

    Science.gov (United States)

    Chen, Dongmei; Meng, Fanzhen; Zhao, Fengjun; Xu, Cao

    2016-01-01

    Cone beam X-ray luminescence tomography can realize fast X-ray luminescence tomography imaging with relatively low scanning time compared with narrow beam X-ray luminescence tomography. However, cone beam X-ray luminescence tomography suffers from an ill-posed reconstruction problem. First, the feasibility of experiments with different penetration and multispectra in small animal has been tested using nanophosphor material. Then, the hybrid reconstruction algorithm with KA-FEM method has been applied in cone beam X-ray luminescence tomography for small animals to overcome the ill-posed reconstruction problem, whose advantage and property have been demonstrated in fluorescence tomography imaging. The in vivo mouse experiment proved the feasibility of the proposed method.

  14. Tussilagone suppresses colon cancer cell proliferation by promoting the degradation of β-catenin

    International Nuclear Information System (INIS)

    Li, Hua; Lee, Hwa Jin; Ahn, Yeon Hwa; Kwon, Hye Jin; Jang, Chang-Young; Kim, Woo-Young; Ryu, Jae-Ha

    2014-01-01

    Highlights: •Tussilagone (TSL) was purified from plant as an inhibitor of Wnt/β-catenin pathway. •TSL suppressed the β-catenin/T-cell factor transcriptional activity. •The proteasomal degradation of β-catenin was induced by TSL. •TSL suppressed the Wnt/β-catenin target genes, cyclin D1 and c-myc. •TSL inhibit the proliferation of colon cancer cells. -- Abstract: Abnormal activation of the Wnt/β-catenin signaling pathway frequently induces colon cancer progression. In the present study, we identified tussilagone (TSL), a compound isolated from the flower buds of Tussilago farfara, as an inhibitor on β-catenin dependent Wnt pathway. TSL suppressed β-catenin/T-cell factor transcriptional activity and down-regulated β-catenin level both in cytoplasm and nuclei of HEK293 reporter cells when they were stimulated by Wnt3a or activated by an inhibitor of glycogen synthase kinase-3β. Since the mRNA level was not changed by TSL, proteasomal degradation might be responsible for the decreased level of β-catenin. In SW480 and HCT116 colon cancer cell lines, TSL suppressed the β-catenin activity and also decreased the expression of cyclin D1 and c-myc, representative target genes of the Wnt/β-catenin signaling pathway, and consequently inhibited the proliferation of colon cancer cells. Taken together, TSL might be a potential chemotherapeutic agent for the prevention and treatment of human colon cancer

  15. Tussilagone suppresses colon cancer cell proliferation by promoting the degradation of β-catenin

    Energy Technology Data Exchange (ETDEWEB)

    Li, Hua [College of Pharmacy and Research Center for Cell Fate Control, Sookmyung Women’s University, 52 Hyochangwon-Gil, Yongsan-Gu, Seoul 140-742 (Korea, Republic of); Lee, Hwa Jin [Department of Natural Medicine Resources, Semyung University, 65 Semyung-ro, Jecheon, Chungbuk 390-711 (Korea, Republic of); Ahn, Yeon Hwa; Kwon, Hye Jin; Jang, Chang-Young; Kim, Woo-Young [College of Pharmacy and Research Center for Cell Fate Control, Sookmyung Women’s University, 52 Hyochangwon-Gil, Yongsan-Gu, Seoul 140-742 (Korea, Republic of); Ryu, Jae-Ha, E-mail: ryuha@sookmyung.ac.kr [College of Pharmacy and Research Center for Cell Fate Control, Sookmyung Women’s University, 52 Hyochangwon-Gil, Yongsan-Gu, Seoul 140-742 (Korea, Republic of)

    2014-01-03

    Highlights: •Tussilagone (TSL) was purified from plant as an inhibitor of Wnt/β-catenin pathway. •TSL suppressed the β-catenin/T-cell factor transcriptional activity. •The proteasomal degradation of β-catenin was induced by TSL. •TSL suppressed the Wnt/β-catenin target genes, cyclin D1 and c-myc. •TSL inhibit the proliferation of colon cancer cells. -- Abstract: Abnormal activation of the Wnt/β-catenin signaling pathway frequently induces colon cancer progression. In the present study, we identified tussilagone (TSL), a compound isolated from the flower buds of Tussilago farfara, as an inhibitor on β-catenin dependent Wnt pathway. TSL suppressed β-catenin/T-cell factor transcriptional activity and down-regulated β-catenin level both in cytoplasm and nuclei of HEK293 reporter cells when they were stimulated by Wnt3a or activated by an inhibitor of glycogen synthase kinase-3β. Since the mRNA level was not changed by TSL, proteasomal degradation might be responsible for the decreased level of β-catenin. In SW480 and HCT116 colon cancer cell lines, TSL suppressed the β-catenin activity and also decreased the expression of cyclin D1 and c-myc, representative target genes of the Wnt/β-catenin signaling pathway, and consequently inhibited the proliferation of colon cancer cells. Taken together, TSL might be a potential chemotherapeutic agent for the prevention and treatment of human colon cancer.

  16. Synthesis of yttrium silicate luminescent materials by sol-gel method

    International Nuclear Information System (INIS)

    Arkhipov, D.V.; Vasina, O.Yu.; Popovich, N.V.; Galaktionov, S.S.; Soshchin, N.P.

    1996-01-01

    Several yttrium-silicate composition with Y 2 O 3 content within 44-56% have been synthesized. it is ascertained that employment of sol-gel technique permits preparation of luminescent materials on yttrium silicate basis, which compare favourably with bath-produced specimens. The influence of phase composition of sol-gel phosphors on basic performance indices: intensity and luminescence spectrum, has been analyzed

  17. Neutron dosimetry using optically stimulated luminescence

    International Nuclear Information System (INIS)

    Miller, S.D.; Eschbach, P.A.

    1991-06-01

    The addition of thermoluminescent (TL) materials within hydrogenous matrices to detect neutron-induced proton recoils for radiation dosimetry is a well-known concept. Previous attempts to implement this technique have met with limited success, primarily due to the high temperatures required for TL readout and the low melting temperatures of hydrogen-rich plastics. Research in recent years at Pacific Northwest laboratories (PNL) has produced a new Optically Stimulated Luminescence (OSL) technique known as the Cooled Optically Stimulated Luminescence (COSL) that offers, for the first time, the capability of performing extremely sensitive radiation dosimetry at low temperatures. In addition to its extreme sensitivity, the COSL technique offers multiple readout capability, limited fading in a one-year period, and the capability of analyzing single grains within a hydrogenous matrix. 4 refs., 10 figs

  18. Blue-green luminescent CdZnSeS nanocrystals synthesized with activated alkyl thiol

    International Nuclear Information System (INIS)

    Xia Xing; Liu Zuli; Du Guihuan; Li Yuebin; Ma Ming; Yao Kailun

    2012-01-01

    Semiconductor nanocrystals with blue-green luminescence are potentially useful in various applications, but the preparation has not been easy compared to regular semiconductor nanocrystals with emission in the orange-red range. In this research alloyed CdZnSeS nanocrystals with luminescence covering the wavelength range from 430 to 560 nm are obtained by a one-step method with the assistance of alkyl thiol compound 1-dodecanethiol, which serves both as the sulfur source and surface ligand. The luminescence of CdZnSeS nanocrystals can be tuned from blue to green by altering the Cd:Zn molar ratio. Besides, the amount of 1-dodecanethiol in the reaction mixture can influence the emission wavelength by restricting the growth of nanocrystals. The dual control of both particle composition and size has enabled the tuning of luminescence to cover the blue-green spectral window. This research presents a convenient method to synthesize nanocrystals with tunable blue-green emission; these materials can be useful in advanced technologies such as photovoltaics, lighting and display. - Highlights: → Obtained blue-green luminescent nanocrystals by a one-step process. → Alkyl thiol used as a sulfur source and a surface stabilizer to control particle size. → Luminescence color of NCs could be easily tuned by changing their composition and particle size simultaneously.

  19. New polymers containing BF2-benzoylacetonate groups. Synthesis, luminescence, excimer and exciplex formation

    International Nuclear Information System (INIS)

    Fedorenko, Elena V.; Mirochnik, Anatolii G.; Beloliptsev, Anton Yu.

    2017-01-01

    In the present study, a new synthetic method for the functionalization of polystyrene (PS) and (styrene-methyl methacrylate) copolymer has been developed. Using the new method, polymers containing BF 2 -benzoylacetonate groups have been obtained through double acylation by acetic anhydride with boron trifluoride. Luminescence of the produced polymers in solutions and films has been studied. Quantum yields of polymer solution luminescence are significantly higher than those of the low-molecular-weight analog – boron difluoride benzoylacetonate. For the polymer, in which styrene fragments are separated by methyl methacrylate groups, at low concentrations of the polymer in solution one observes the monomer luminescence of BF 2 -benzoylacetonate groups, while at high concentrations – the excimer luminescence. In case of PS-based polymers, in which BF 2 -benzoylacetonate groups and phenyl rings are not separated, in diluted solutions one observes the fluorescence of the intramolecular exciplexes, while at the concentration increase – the luminescence of intermolecular exciplexes. The ability of excimer formation is responsible for the increased photostability of the produced polymers. - Highlights: •Polymers containing BF 2 -benzoylacetonate groups have been synthesized. •Luminescence of the produced polymers in solutions and films has been studied. •Formation of excimers and exciplexes in solution has been revealed. •Formation of excimers in films increases their photostability.

  20. Porous glasses as a host of luminescent materials, their applications and site selective determination

    Energy Technology Data Exchange (ETDEWEB)

    Reisfeld, Renata, E-mail: renata.reisfeld@mail.huji.ac.il [Institute of Chemistry, Hebrew University of Jerusalem, Givat-Ram, Jerusalem 91904 (Israel); Jasinska, Bozena [Institute of Physics, Maria Curie-Sklodowska University, Pl. M. Curie-Skłodowsskiej 1, 20-031 Lublin (Poland); Levchenko, Viktoria [Institute of Chemistry, Hebrew University of Jerusalem, Givat-Ram, Jerusalem 91904 (Israel); Gorgol, Marek [Institute of Physics, Maria Curie-Sklodowska University, Pl. M. Curie-Skłodowsskiej 1, 20-031 Lublin (Poland); Saraidarov, Tsiala; Popov, Inna [Institute of Chemistry, Hebrew University of Jerusalem, Givat-Ram, Jerusalem 91904 (Israel); Antropova, Tatiana [I. V. Grebenshchikov Institute of the Chemistry of Silicates, Russian Academy of Sciences, Nab. Makarova, 2, Liter B, Saint-Petersburg 199034 (Russian Federation); Rysiakiewicz-Pasek, Ewa [Institute of Physics, Wroclaw University of Technology, W. Wyspianskiego 27, 50-370 Wroclaw (Poland)

    2016-01-15

    The site selective distribution of pore sizes in pure porous glasses and glasses doped by a luminescent colorant is determined by luminescent spectroscopy, SEM, SAXS and PALS. The potential applications of the studied materials as environmental and biological sensors are outlined. We suggest how luminescent porous glasses doped by complexes of Gd can act as solid scintillators in tracing elementary particles like neutrino. - Highlights: • Porous glasses are a medium for large number of luminescent materials. • Size distribution of empty and filled pores is studied. • The validity of data obtained by different methods is analyzed.

  1. Luminescence recognition of different organophosphorus pesticides by the luminescent Eu(III)-pyridine-2,6-dicarboxylic acid probe

    Energy Technology Data Exchange (ETDEWEB)

    Azab, Hassan A., E-mail: azab2@yahoo.com [Chemistry Department, Faculty of Science, Suez Canal University, Ismailia 41522 (Egypt); Duerkop, Axel [Institute of Analytical Chemistry, Chemo and Biosensors, Regensburg University, D-93040 Regensburg (Germany); Anwar, Z.M.; Hussein, Belal H.M.; Rizk, Moustafa A.; Amin, Tarek [Chemistry Department, Faculty of Science, Suez Canal University, Ismailia 41522 (Egypt)

    2013-01-08

    Highlights: Black-Right-Pointing-Pointer Europium (III) luminescence quenching has been used for sensing organophosphorous pesticides. Black-Right-Pointing-Pointer Four guest pesticides chlorfenvinphos, malathion, azinphos, and paraxon ethyl were used. Black-Right-Pointing-Pointer A sensitive rapid, cheap direct method for the determination of the pesticides has been developed. Black-Right-Pointing-Pointer The method was applied to the determination of the OPs in tap, river, mineral, and waste waters. - Abstract: Luminescence quenching of a novel long lived Eu(III)-pyridine-2,6-dicarboxylic acid probe of 1:2 stoichiometric ratio has been studied in 0.10 volume fraction ethanol-water mixture at pH 7.5 (HEPES buffer) in the presence of the organophosphorus pesticides chlorfenvinphos (P1), malathion (P2), azinphos (P3), and paraxon ethyl (P4). The luminescence intensity of Eu(III)-(PDCA){sub 2} probe decreases as the concentration of the pesticide increases. It was observed that the quenching due to P3 and P4 proceeds via both diffusional and static quenching processes. Direct methods for the determination of the pesticides under investigation have been developed using the luminescence quenching of Eu(III)-pyridine-2,6-dicarboxylic acid probe in solution. The linear range for determination of the selected pesticides is 1.0-35.0 {mu}M. The detection limits were 0.24-0.55 {mu}M for P3, P4, and P1 and 2.5 {mu}M for P2, respectively. The binding constants (K), and thermodynamic parameters of the OPs with Eu(III)-(PDCA){sub 2} were evaluated. Positive and negative values of entropy ({Delta}S) and enthalpy ({Delta}H) changes for Eu(III)-(PDCA){sub 2}-P1 ternary complex were calculated. As the waters in this study do not contain the above mentioned OPs over the limit detectable by the method, a recovery study was carried out after the addition of the adequate amounts of the organophosphorus pesticides under investigation.

  2. Luminescence lifetimes in natural quartz annealed beyond its second phase inversion temperature

    International Nuclear Information System (INIS)

    Chithambo, M.L.

    2015-01-01

    The influence of annealing, irradiation dose, preheating and measurement temperature on luminescence lifetimes has been studied in quartz annealed at 1000 °C. The measurements were supplemented by studies on quartz annealed at 900 and 800 °C. Lifetimes increase with dose as well as with temperature and duration of annealing between 800 and 1000 °C. Preheating produces the same effect. The changes are accounted for in terms of hole-transfer from the non-radiative luminescence centre to and between radiative centres. The influence of measurement temperature on lifetimes depends on whether the stimulation is carried out from ambient to 200 °C or otherwise. This result is unlike that in quartz annealed at or below 500 °C where lifetimes are independent of the direction of heating. In particular, lifetimes decrease monotonically when measurements are made from 20 to 200 °C but not when recorded from 200 to 20 °C. The latter produces a pattern resembling that in quartz annealed up to 500 °C. The results are concluded as evidence of thermal effects on separate luminescence centres. In support of this, different values of the activation energy for thermal quenching were found for each supposed luminescence centre. The change of the corresponding luminescence intensity with temperature is also qualitatively consistent with this notion. - Highlights: • Luminescence lifetimes in natural quartz annealed beyond its second phase inversion temperature is reported. • Lifetimes increase with dose, annealing between 800 and 1000 °C, and preheating. • Lifetimes under stimulation temperature are affected by direction of heating. • Changes are accounted for in terms of hole-transfer luminescence centres.

  3. Luminescence of water or ice as a new detection method for magnetic monopoles

    Directory of Open Access Journals (Sweden)

    Pollmann Anna Obertacke

    2017-01-01

    We present analysis techniques to use luminescence in neutrino telescopes and discuss experimental setups to measure the light yield of luminescence for the particular conditions in neutrino detectors.

  4. Novel Luminescent Multilayer Films Containing π-Conjugated Anionic Polymer with Electronic Microenvironment

    Directory of Open Access Journals (Sweden)

    Tianlei Wang

    2016-09-01

    Full Text Available Layered double hydroxides (LDHs, luminescent π-conjugated anionic polymer and montmorillonite (MMT were orderly assembled into luminescent multilayer films via layer-by-layer self-assembly method. The electronic microenvironment (EME, the structure of which is like a traditional capacitor, can be constructed by exfoliated LDHs or MMT nanosheets. In addition, the rigid inorganic laminated configuration can offer stable surroundings between the interlayers. As a result, we conclude that EME can extend the luminescent lifespans of multilayer films substantially, due to affecting relaxation times of π-conjugated anionic polymer. Consequently, because of the remarkable impact on better photoemission behaviors of luminescent π-conjugated anionic polymer, EME assembled by LDHs or MMT nanosheets have had high hopes attached to them. They are expected to have the potential for designing, constructing, and investigating novel light-emitting thin films.

  5. Advances in luminescence instrument systems

    DEFF Research Database (Denmark)

    Bøtter-Jensen, L.; Bulur, E.; Duller, G.A.T.

    2000-01-01

    We report on recent advances in the development of luminescence measurement systems and techniques at Riso. These include: (1) optical stimulation units based on new-generation powerful blue light (470 nm) emitting diodes providing up to 28 mW/cm(2) for OSL measurements; (2) an infrared (830 nm...

  6. Luminescence in Sulfides: A Rich History and a Bright Future

    Directory of Open Access Journals (Sweden)

    Philippe F. Smet

    2010-04-01

    Full Text Available Sulfide-based luminescent materials have attracted a lot of attention for a wide range of photo-, cathodo- and electroluminescent applications. Upon doping with Ce3+ and Eu2+, the luminescence can be varied over the entire visible region by appropriately choosing the composition of the sulfide host. Main application areas are flat panel displays based on thin film electroluminescence, field emission displays and ZnS-based powder electroluminescence for backlights. For these applications, special attention is given to BaAl2S4:Eu, ZnS:Mn and ZnS:Cu. Recently, sulfide materials have regained interest due to their ability (in contrast to oxide materials to provide a broad band, Eu2+-based red emission for use as a color conversion material in white-light emitting diodes (LEDs. The potential application of rare-earth doped binary alkaline-earth sulfides, like CaS and SrS, thiogallates, thioaluminates and thiosilicates as conversion phosphors is discussed. Finally, this review concludes with the size-dependent luminescence in intrinsic colloidal quantum dots like PbS and CdS, and with the luminescence in doped nanoparticles.

  7. Ab initio calculations of cross luminescence materials

    International Nuclear Information System (INIS)

    Kanchana, V.

    2016-01-01

    Abintio calculations have been performed to study the structural, electronic, and optical properties of ABX 3 (A=alkali, B=alkaline-earth, and X=halide) compounds. The ground state properties are calculated using the pseudopotential method with the inclusion of van der Waals interaction, which we find inevitable in reproducing the experimental structure properties in alkali iodides because of its layered structure. All calculations were performed using the Full-Potential Linearized Augmented Plane Wave method. The band structures are plotted with various functionals and we find the newly developed Tran and Blaha modified Becke-Johnson potential to improve the band gap significantly. The optical properties such as complex dielectric function, refractive index, and absorption spectra are calculated which clearly reveal the optically isotropic nature of these materials though being structurally anisotropic, which is the key requirement for ceramic scintillators. Cross luminescence materials are very interesting because of its fast decay. One of the major criteria for the cross luminescence to happen is the energy difference between valence band and next deeper core valence band being lesser when compared to energy gap of the compound, so that radiative electronic transition may occur between valence band and core valence band. We found this criteria to be satisfied in all the studied compounds leading to cross luminescence except for KSrI 3 , RbSrI 3 . The present study suggest that among the six compounds studied, CsSrI 3 , CsMgCl 3 , CsCaCl 3 , and CsSrCl 3 compounds are cross luminescence materials, which is well explained from the band structure, optical properties calculations. Chlorides are better scintillators that iodides and CsMgCl 3 is found to be promising one among the studied compounds. Apart from these materials we have also discussed electronic structure and optical properties of other scintillator compounds. (author)

  8. Process for producing a self luminescent material

    Energy Technology Data Exchange (ETDEWEB)

    Abe, E

    1962-01-28

    A self luminescent material is produced by a process comprising applying a hydroxide or fluoride of promethium-147 suspended in a medium of paraffinic acid to the surface of a fluorescent body. Promethium-147 decays with a half-life of 2.6 years and emits beta-rays but not alpha- and gamma-rays so that it is suitable for manufacturing self luminescent materials. A chloride of promethium-147 cannot be employed because its structure is destroyed by acids. Although fluorides and hydroxides of promethium-147 are difficult to mix with the fluorescent body material, they become mixable when paraffinic acids containing from 12 to 20 carbon atoms, (for example, steric acid, palmitic acid and margaric acid) are used as a medium. In embodiments, the self luminescent materials are prepared by either neutralization of a promethium-147 chloride solution having a specific radioactivity of 1.2 c/cc. with an ammonium hydroxide solution to form gelatinous hydroxide, or the reaction of a promethium-147 chloride solution with H/sub 2/SiF/sub 6/ by heating at 80/sup 0/C to form a fluoride of promethium-147. The products have a specific radioactivity of 8 to 12 mc/g. These products are suspended in vehicles of polystyrene and methacrylic resin to produce the self luminescent coating materials. Tests show that the initical brightness is comparatively high, the decreasing rate of brightness is small, no blackening effects by alpha-rays occur and costs are low. The brightness of the coating containing promethium-147 is 82-85 after 5 days, 100-105 after 100 days and 82-92 after 180 days. With respect to the coating containing radium the values are 31-70 after 5 days, 28-49 after 100 days and 19-31 after 180 days.

  9. Luminescence properties of Ce3+ doped gadolinium-calcium-silicaborate glass scintillator

    International Nuclear Information System (INIS)

    Park, J.M.; Ha, D.H.; Kaewjeang, S.; Maghanemi, U.; Kothan, S.; Kaewkhao, J.; Kim, H.J.

    2016-01-01

    In this work, the Ce 3+ doped gadolinium-calcium-silicaborate glass scintillators of the composition ratio 25Gd 2 O 3 :10CaO:10SiO 2 :(55−x)B 2 O 3 :xCeF 3 , have been fabricated by using the melt-quenching technique. The doping concentration of the Ce 3+ was varied from 0.05 mol% to 2.5 mol%. The 4f-5d transition of the Ce 3+ allowed scintillation with a fast decay time. The absorption spectrum, X-ray induced emission spectrum, photo luminescence spectrum, laser luminescence spectrum and decay time of the scintillators were measured for studying the luminescence properties. From the X-ray induced emission spectrum result, we checked the trend between doping concentration and light yield. The laser induced luminescence spectrum was measured while changing the temperature from 300 K to 10 K. We also measured the decay time by using the laser excitation of the 0.15 mol% Ce 3+ doped glass scintillator. - Highlights: • Ce 3+ doped gadolinium-calcium-silicaborate glass scintillators were developed. • Glass is easily fabricated with large sizes and various doping materials. • The luminescence properties are studied by using various radiation sources. • The light yield and decay time were measured at low temperature. • One decay time component is found.

  10. Temperature and Pressure Sensors Based on Spin-Allowed Broadband Luminescence of Doped Orthorhombic Perovskite Structures

    Science.gov (United States)

    Eldridge, Jeffrey I. (Inventor); Chambers, Matthew D. (Inventor)

    2014-01-01

    Systems and methods that are capable of measuring pressure or temperature based on luminescence are discussed herein. These systems and methods are based on spin-allowed broadband luminescence of sensors with orthorhombic perovskite structures of rare earth aluminates doped with chromium or similar transition metals, such as chromium-doped gadolinium aluminate. Luminescence from these sensors can be measured to determine at least one of temperature or pressure, based on either the intense luminescence of these sensors, even at high temperatures, or low temperature techniques discussed herein.

  11. Development of a ratiometric time-resolved luminescence sensor for pH based on lanthanide complexes

    International Nuclear Information System (INIS)

    Liu Mingjing; Ye Zhiqiang; Xin Chenglong; Yuan Jingli

    2013-01-01

    Highlights: ► A lanthanide complex-based ratiometric luminescent pH sensor was developed. ► The sensor can luminously respond to pH in weakly acidic to neutral media. ► The sensor can be used for monitoring pH with time-resolved luminescence mode. ► The sensor can be also used for monitoring pH with absorbance mode. ► The utility of the sensor for the luminescent cell imaging was demonstrated. - Abstract: Time-resolved luminescence bioassay technique using lanthanide complexes as luminescent probes/sensors has shown great utilities in clinical diagnostics and biotechnology discoveries. In this work, a novel terpyridine polyacid derivative that can form highly stable complexes with lanthanide ions in aqueous media, (4′-hydroxy-2,2′:6′,2′′-terpyridine-6,6′′-diyl) bis(methylenenitrilo) tetrakis(acetic acid) (HTTA), was designed and synthesized for developing time-resolved luminescence pH sensors based on its Eu 3+ and Tb 3+ complexes. The luminescence characterization results reveal that the luminescence intensity of HTTA–Eu 3+ is strongly dependent on the pH values in weakly acidic to neutral media (pK a = 5.8, pH 4.8–7.5), while that of HTTA–Tb 3+ is pH-independent. This unique luminescence response allows the mixture of HTTA–Eu 3+ and HTTA–Tb 3+ (the HTTA–Eu 3+ /Tb 3+ mixture) to be used as a ratiometric luminescence sensor for the time-resolved luminescence detection of pH with the intensity ratio of its Tb 3+ emission at 540 nm to its Eu 3+ emission at 610 nm, I 540nm /I 610nm , as a signal. Moreover, the UV absorption spectrum changes of the HTTA–Eu 3+ /Tb 3+ mixture at different pHs (pH 4.0–7.0) also display a ratiometric response to the pH changes with the ratio of absorbance at 290 nm to that at 325 nm, A 290nm /A 325nm , as a signal. This feature enables the HTTA–Eu 3+ /Tb 3+ mixture to have an additional function for the pH detection with the absorption spectrometry technique. For loading the complexes into the

  12. Effects of Iranian Economic Reforms on Equity in Social and Healthcare Financing: A Segmented Regression Analysis.

    Science.gov (United States)

    Zandian, Hamed; Takian, Amirhossein; Rashidian, Arash; Bayati, Mohsen; Zahirian Moghadam, Telma; Rezaei, Satar; Olyaeemanesh, Alireza

    2018-03-01

    One of the main objectives of the Targeted Subsidies Law (TSL) in Iran was to improve equity in healthcare financing. This study aimed at measuring the effects of the TSL, which was implemented in Iran in 2010, on equity in healthcare financing. Segmented regression analysis was applied to assess the effects of TSL implementation on the Gini and Kakwani indices of outcome variables in Iranian households. Data for the years 1977-2014 were retrieved from formal databases. Changes in the levels and trends of the outcome variables before and after TSL implementation were assessed using Stata version 13. In the 33 years before the implementation of the TSL, the Gini index decreased from 0.401 to 0.381. The Gini index and its intercept significantly decreased to 0.362 (pfinancing. Hence, while measuring the long-term impact of TSL is paramount, healthcare decision-makers need to consider the efficacy of the TSL in order to develop plans for achieving the desired equity in healthcare financing.

  13. Luminescence properties of uranyl-acetate species

    Energy Technology Data Exchange (ETDEWEB)

    Brinkmann, Hannes; Moll, Henry [Helmholtz-Zentrum Dresden-Rossendorf e.V., Dresden (Germany). Inst. of Resource Ecology; Stumpf, Thorsten [Helmholtz-Zentrum Dresden-Rossendorf e.V., Dresden (Germany). Biogeochemistry

    2017-06-01

    Time-resolved laser-induced fluorescence spectroscopy (TRLFS) was applied to characterize uranium(VI)- acetate species based on their luminescence properties. In contrast to previous interpretations, no indications were detected for the existence of the 1: 3 complex.

  14. Luminescence and energy transfer processes in rare earth compounds

    International Nuclear Information System (INIS)

    Vliet, J.P.M. van.

    1989-01-01

    In this thesis some studies are presented of the luminescence and energy transfer in compounds containing Eu 3+ , Pr 3+ and Gd 3+ ions. Ch. 2 deals with the energy migration in the system Gd 1 - xEu x(IO 3) 3. In ch 3 the luminescence properties of the Pr 3+ ion in the system La 1 - xPr xMgAl 1 10 1 9 are reported. Ch. 4 discusses the luminescence properties of alkali europium double tungstates and molybdates AEuW 20 8 and AEuMo 20 * (A + = alkali metal atom). The luminiscence and energy migration characteristics of the isostructural system LiGd 1 - xEu xF 4 and Gd 1 - xEu xNbO 4 are reported in ch. 5. In ch. 6 the mechanism of energy migration in (La,Gd)AlO 3 and (Gd,Eu)AlO 3 is discussed. Ch. 7 deals with the system Na 5(Gd,Eu) (WO 4) 4. In ch. 8 the luminescence and energy transfer properties of two europium tellurite anti-glass phases are reported. The two phases are Eu 1 . 7 9TeO x, which has a pseudotetragonal structure, and Eu 1 . 0 6TeO x, which has a monoclinic, ordered structure. (author). 201 refs.; 39 figs.; 8 tabs

  15. Application of Quantum Dot nanocrystal in Luminescent solar concentrators

    Science.gov (United States)

    Bakhoda, Shokoufeh; Khalaji Assadi, Morteza; Ahmadi Kandjani, Sohrab; Kayiem, Hussain H. Al; Hussain Bhat, Aamir

    2018-03-01

    The basic design of luminescent solar concentrator is a transparent plate doped with an appropriate luminescent material (organic dyes, quantum dots), which is able to absorb sunlight (direct and diffuse), and then guides photons produced by photoluminescence to its narrow edges where they are converted by photovoltaic cells. Unfortunately, LSCs have suffered from numerous efficiency losses. Therefore, new luminescent species and novel approaches are needed for its practical application. This paper deals with investigation of nonhazardous, environmental friendly luminescent species include CuInS2/ZnS core/shell QDs. The CuInS2/ZnS QDs possess advantages of Stocks shift as large as more than 130 nm and high photoluminescence quantum yield of 80%. The paper presents the effect of large stock shift CuInS2/ZnS QDs on reducing the reabsorption losses in LSC by using experimental investigation. The LSC sheets were fabricated by dispersing CuInS2/ZnS QDs particles in a polymethylmethacrylate waveguide. A series of LSCs (dimension 4.0 cm × 3.0 cm × 0.3cm) with different CuInS2/ZnS QDs particles concentration (0.015 and 0.03 wt.%) were fabricated and their optical properties (absorptions/emissions) were characterized. The results show that the CuInS2/ZnS QDs-LSC provides a promising way for the reduction of reabsorption losses in LSCs.

  16. Dosimetry based on thermally and optically stimulated luminescence

    Energy Technology Data Exchange (ETDEWEB)

    Agersnap Larsen, Niels

    1999-01-01

    Thermally Stimulated Luminescence (TL) and Optically Stimulated Luminescence (OSL) properties of quartz and {alpha}-Al{sub 2}O{sub 3} have been investigated. Anneling-induced OSL and TL sensitivity changes in quartz has been investigated by experiments and modelling. This study does not support a pre-dose effect to account for the observed annealing-induced sensitivity change. The experimental data indicates a more simple mechanism that involves alteration of the concentration of the defect centers. Results from modelling of removal or creation of defect centers comparing well with experimentally obtained data. Thermal quenching of luminescence for the main emission center, the F-center, in {alpha}-Al{sub 2}O{sub 3}:C has been investigated by analysing TL curves obtained at different heating rates. The thermal quenching dependence of luminescence is found to follow the classical Mott-Seitz expression. Basic investigations of OSL properties of {alpha}Al{sub 2}O{sub 3}:C, including: the thermal depth of the OSL traps, the temperature dependence of OSL, and the OSL stimulation spectra. Simultaneous measurements of TL and thermally stimulated conductivity (TSC) are presented for {gamma}-irradiated {alpha}Al{sub 2}O{sub 3}:C. Activation energy analysis of the data reveals a superposition of several first-order TL and TSC peaks caused by release of charge carriers from a distribution of trapping states. Furthermore a description of an experimental method developed to determine the sign of the thermally released charge carriers has been presented. (au) 8 tabs., 59 ills., 90 refs.

  17. Interactions between bicarbonate, potassium, and magnesium, and sulfur-dependent induction of luminescence in Vibrio fischeri.

    Science.gov (United States)

    Tabei, Yosuke; Era, Mariko; Ogawa, Akane; Morita, Hiroshi

    2012-06-01

    In spite of its central importance in research efforts, the relationship between seawater compounds and bacterial luminescence has not previously been investigated in detail. Thus, in this study, we investigated the effect of cations (Na(+) , K(+) , NH(4) (+) , Mg(2+) , and Ca(2+) ) and anions (Cl(-) , HCO(3) (-) , CO(3) (2-) , and NO(3) (-) ) on the induction of both inorganic (sulfate, sulfite, and thiosulfate) and organic (L-cysteine and L-cystine) sulfur-dependent luminescence in Vibrio fischeri. We found that HCO(3) (-) (bicarbonate) and CO(3) (2-) (carbonate), in the form of various compounds, had a stimulatory effect on sulfur-dependent luminescence. The luminescence induced by bicarbonate was further promoted by the addition of magnesium. Potassium also increased sulfur-dependent luminescence when sulfate or thiosulfate was supplied as the sole sulfur source, but not when sulfite, L-cysteine, or L-cystine was supplied. The positive effect of potassium was accelerated by the addition of magnesium and/or calcium. Furthermore, the additional supply of magnesium improved the induction of sulfite- or L-cysteine-dependent luminescence, but not the l-cystine-dependent type. These results suggest that sulfur-dependent luminescence of V. fischeri under nutrient-starved conditions is mainly controlled by bicarbonate, carbonate, and potassium. In addition, our results indicate that an additional supply of magnesium is effective for increasing V. fischeri luminescence. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  18. Single fiber temperature probe configuration using anti-Stokes luminescence from Cr:GdAlO3

    Science.gov (United States)

    Eldridge, Jeffrey I.

    2018-06-01

    Single-photon excitation of anti-Stokes-shifted emission from a thermographic phosphor allows operation of a luminescence decay-based single fiber temperature probe with negligible interference from background fiber-generated Raman scattering. While single fiber probe configurations for luminescence-based fiber optic thermometers offer advantages of simple design, compactness, and superior emission light collection efficiency, their effective use has been limited by interference from Raman scattering in the fiber probe and excitation delivery fiber that produces distortion of the luminescence decay that follows the excitation pulse. The near elimination of interference by background fiber-generated Raman scattering was demonstrated by incorporating a Cr-doped GdAlO3 (Cr:GdAlO3) thermographic phosphor as the sensing element at the end of a single fiber luminescence decay-based thermometer and detecting anti-Stokes-shifted luminescence centered at 542 or 593 nm produced by 695 nm excitation. Measurements were performed using both silica (up to 1150 °C) and single-crystal YAG (up to 1200 °C) fiber-based thermometers. Selection of emission detection centered at 542 nm greatly benefited the YAG fiber probe measurements by practically eliminating detection of otherwise significant luminescence from Cr3+ impurities in the YAG fiber. For both the silica and YAG fiber probes, the relative benefit of adopting single-photon excitation of anti-Stokes-shifted luminescence was evaluated by comparison with results obtained by conventional 532 nm excitation of Stokes-shifted luminescence.

  19. Evaluation of one-step luminescent cyanoacrylate fuming.

    Science.gov (United States)

    Khuu, Alicia; Chadwick, Scott; Spindler, Xanthe; Lam, Rolanda; Moret, Sébastien; Roux, Claude

    2016-06-01

    One-step luminescent cyanoacrylates have recently been introduced as an alternative to the conventional cyanoacrylate fuming methods. These new techniques do not require the application of a luminescent post-treatment in order to enhance cyanoacrylate-developed fingermarks. In this study, three one-step polymer cyanoacrylates: CN Yellow Crystals (Aneval Inc.), PolyCyano UV (Foster+Freeman Ltd.) and PECA Multiband (BVDA), and one monomer cyanoacrylate: Lumikit™ (Crime Scene Technology), were evaluated against a conventional two-step cyanoacrylate fuming method (Cyanobloom (Foster+Freeman Ltd.) with rhodamine 6G stain). The manufacturers' recommended conditions or conditions compatible with the MVC™ 1000/D (Foster+Freeman Ltd.) were assessed with fingermarks aged for up to 8 weeks on non-porous and semi-porous substrates. Under white light, Cyanobloom generally gave better development than the one-step treatments across the substrates. Similarly when viewed under the respective luminescent conditions, Cyanobloom with rhodamine 6G stain resulted in improved contrast against the one-step treatments except on polystyrene, where PolyCyano UV and PECA Multiband gave better visualisation. Rhodamine 6G post-treatment of one-step samples did not significantly enhance the contrast of any of the one-step treatments against Cyanobloom/rhodamine 6G-treated samples. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

  20. Highly Water-Stable Lanthanide-Oxalate MOFs with Remarkable Proton Conductivity and Tunable Luminescence.

    Science.gov (United States)

    Zhang, Kun; Xie, Xiaoji; Li, Hongyu; Gao, Jiaxin; Nie, Li; Pan, Yue; Xie, Juan; Tian, Dan; Liu, Wenlong; Fan, Quli; Su, Haiquan; Huang, Ling; Huang, Wei

    2017-09-01

    Although proton conductors derived from metal-organic frameworks (MOFs) are highly anticipated for various applications including solid-state electrolytes, H 2 sensors, and ammonia synthesis, they are facing serious challenges such as poor water stability, fastidious working conditions, and low proton conductivity. Herein, we report two lanthanide-oxalate MOFs that are highly water stable, with so far the highest room-temperature proton conductivity (3.42 × 10 -3 S cm -1 ) under 100% relative humidity (RH) among lanthanide-based MOFs and, most importantly, luminescent. Moreover, the simultaneous response of both the proton conductivity and luminescence intensity to RH allows the linkage of proton conductivity with luminescence intensity. This way, the electric signal of proton conductivity variation versus RH will be readily translated to optical signal of luminescence intensity, which can be directly visualized by the naked eye. If proper lanthanide ions or even transition-metal ions are used, the working wavelengths of luminescence emissions can be further extended from visible to near infrared light for even wider-range applications. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  1. Spectral luminescence and geochemistry of coral aragonite: Effects of whole-core treatment

    NARCIS (Netherlands)

    Nagtegaal, R.; Grove, C.A.; Kasper, S.; Zinke, J.; Brummer, G.J.A.

    2012-01-01

    Luminescent and geochemical properties of coral skeletons are increasingly used for time-series analysis to resolve past and ongoing changes in environmental and climatic conditions. Corals also contain non-skeletal matter which not only quenches luminescence but is also reported to compromise

  2. Radiation-induced growth and isothermal decay of infrared-stimulated luminescence from feldspar

    DEFF Research Database (Denmark)

    Guralnik, Benny; Li, Bo; Jain, Mayank

    2015-01-01

    the growth and decay of laboratory-regenerated luminescence signals. Here we review a selection of common models describing the response of infrared stimulated luminescence (IRSL) of feldspar to constant radiation and temperature as administered in the laboratory. We use this opportunity to introduce...

  3. Kinetic study of Tb/sup 3 +/(/sup 5/D/sub 3/) luminescence in phosphate glasses

    Energy Technology Data Exchange (ETDEWEB)

    Anisimov, V.A.; Dmitryuk, A.V.; Karapetyan, G.O.

    1986-01-01

    This paper presents precise determinations of the kinetics of terbium luminescence over a broad dynamic range, in order to refine the mechanism of concentration quenching of the Tb/sup 3 +/(/sup 5/D/sub 3/) luminescence in glasses. After establishing the mechanism of Tb/sup 3 +/(/sup 5/D/sub 3/) luminescence quenching by the iteration method, the authors determine the value of the parameter for an arbitrary concentration of the activator. Results of this study show that the mechanism of concentration quenching of luminescence is static dipole-dipole interaction of terbium ions.

  4. Preparation and Evaluation of Oxaliplatin Thermosensitive Liposomes with Rapid Release and High Stability.

    Directory of Open Access Journals (Sweden)

    Chunying Zeng

    Full Text Available Oxaliplatin (OXP was reported to show low anti-tumor activity when used alone and to display side effects; this low activity was attributed to high partitioning to erythrocytes and low accumulation in tumors. Thermosensitive liposomes (TSL were considered able to specifically deliver drugs to heated tumors and to resolve the OXP distribution problem. Regretfully, TSL encapsulating doxorubicin did not demonstrate significant improvement in progression-free survival. Drug release below 41°C and significant leakage were considered major reasons for the failure. The purpose of this study was to acquire OXP TSL with rapid release at the triggered temperature and high stability at body temperature and at storage temperatures. A small quantity of poloxamer 188 was introduced into the TSL formulation to stabilize the encapsulated drug. It was shown that the addition of poloxamer 188 had no influence on the TSL characteristics. More than 90% of OXP was released within 10 min at 42°C, and less than 15% was released within 60 min at temperatures below 39°C. TSL were stable at 37°C for 96 h and at 4°C for 6 months. The anti-tumor activity of TSL at the dose of 2.5 mg/kg was certified to be equal to those of OXP injection and non-thermosensitive liposomes (NTSL at the dose of 5 mg/kg, and significant improvement of tumor inhibition was observed in TSL compared with injection and NTSL at the same dose. It was also shown from the histological transmutation of tumors that TSL had stronger anti-tumor activity. Therefore, it could be concluded that TSL composed of a proper amount of poloxamer had rapid release and high stability, and OXP TSL would be anticipated to exert prominent anti-tumor activity in the clinic.

  5. Development of a ratiometric time-resolved luminescence sensor for pH based on lanthanide complexes.

    Science.gov (United States)

    Liu, Mingjing; Ye, Zhiqiang; Xin, Chenglong; Yuan, Jingli

    2013-01-25

    Time-resolved luminescence bioassay technique using lanthanide complexes as luminescent probes/sensors has shown great utilities in clinical diagnostics and biotechnology discoveries. In this work, a novel terpyridine polyacid derivative that can form highly stable complexes with lanthanide ions in aqueous media, (4'-hydroxy-2,2':6',2''-terpyridine-6,6''-diyl) bis(methylenenitrilo) tetrakis(acetic acid) (HTTA), was designed and synthesized for developing time-resolved luminescence pH sensors based on its Eu(3+) and Tb(3+) complexes. The luminescence characterization results reveal that the luminescence intensity of HTTA-Eu(3+) is strongly dependent on the pH values in weakly acidic to neutral media (pK(a) = 5.8, pH 4.8-7.5), while that of HTTA-Tb(3+) is pH-independent. This unique luminescence response allows the mixture of HTTA-Eu(3+) and HTTA-Tb(3+) (the HTTA-Eu(3+)/Tb(3+) mixture) to be used as a ratiometric luminescence sensor for the time-resolved luminescence detection of pH with the intensity ratio of its Tb(3+) emission at 540 nm to its Eu(3+) emission at 610 nm, I(540 nm)/I(610 nm), as a signal. Moreover, the UV absorption spectrum changes of the HTTA-Eu(3+)/Tb(3+) mixture at different pHs (pH 4.0-7.0) also display a ratiometric response to the pH changes with the ratio of absorbance at 290 nm to that at 325 nm, A(290 nm)/A(325 nm), as a signal. This feature enables the HTTA-Eu(3+)/Tb(3+) mixture to have an additional function for the pH detection with the absorption spectrometry technique. For loading the complexes into the living cells, the acetoxymethyl ester of HTTA was synthesized and used for loading HTTA-Eu(3+) and HTTA-Tb(3+) into the cultured HeLa cells. The luminescence imaging results demonstrated the practical utility of the new sensor for the time-resolved luminescence cell imaging application. Copyright © 2012 Elsevier B.V. All rights reserved.

  6. Surrogate MRI markers for hyperthermia-induced release of doxorubicin from thermosensitive liposomes in tumors.

    Science.gov (United States)

    Peller, Michael; Willerding, Linus; Limmer, Simone; Hossann, Martin; Dietrich, Olaf; Ingrisch, Michael; Sroka, Ronald; Lindner, Lars H

    2016-09-10

    The efficacy of systemically applied, classical anti-cancer drugs is limited by insufficient selectivity to the tumor and the applicable dose is limited by side effects. Efficacy could be further improved by targeting of the drug to the tumor. Using thermosensitive liposomes (TSL) as a drug carrier, targeting is achieved by control of temperature in the target volume. In such an approach, effective local hyperthermia (40-43°C) (HT) of the tumor is considered essential but technically challenging. Thus, visualization of local heating and drug release using TSL is considered an important tool for further improvement. Visualization and feasibility of chemodosimetry by magnetic resonance imaging (MRI) has previously been demonstrated using TSL encapsulating both, contrast agent (CA) and doxorubicin (DOX) simultaneously in the same TSL. Dosimetry has been facilitated using T1-relaxation time change as a surrogate marker for DOX deposition in the tumor. To allow higher loading of the TSL and to simplify clinical development of new TSL formulations a new approach using a mixture of TSL either loaded with DOX or MRI-CA is suggested. This was successfully tested using phosphatidyldiglycerol-based TSL (DPPG2-TSL) in Brown Norway rats with syngeneic soft tissue sarcomas (BN175) implanted at both hind legs. After intravenous application of DOX-TSL and CA-TSL, heating of one tumor above 40°C for 1h using laser light resulted in highly selective DOX uptake. The DOX-concentration in the heated tumor tissue compared to the non-heated tumor showed an almost 10-fold increase. T1 and additional MRI surrogate parameters such as signal phase change were correlated to intratumoral DOX concentration. Visualization of DOX delivery in the sense of a chemodosimetry was demonstrated. Although phase-based MR-thermometry was affected by CA-TSL, phase information was found suitable for DOX concentration assessment. Local differences of DOX concentration in the tumors indicated the need for

  7. Bistable luminescence of trivalent rare-earth ions in crystals

    International Nuclear Information System (INIS)

    Sole, Jose Garcia; Ramirez O, Maria de la; Rodenas, Airan; Jaque, Daniel; Bausa, Luisa; Bettinelli, Marco; Speghini, Adolfo; Cavalli, Enrico; Ivleva, Lioudmila

    2006-01-01

    In this work, we have examined three new bistable systems based on the luminescence of three different crystals activated with trivalent rare earth ions. We have focussed our attention on Yb 3+ ions activators, for which the most relevant results are obtained. The first crystal, Sr 0.6 Ba 0.4 Nb 2 O 6 , is a ferroelectric material with a relatively low phase transition temperature (∼370 K), which provides bistability in the luminescence of Yb 3+ ions due to the thermal hysteresis associated with phase transition. The second crystal, LiNbO 3 , provides an intrinsic bistability in the luminescence of Yb 3+ ions, which is driven by changes in the excitation intensity. In the third crystal, NdPO 4 , a new mechanism of excitation intensity driven bistability is obtained when activated with Yb 3+ ions, due to a interplay between the Nd 3+ ↔Yb 3+ energy transfer and back transfer processes

  8. Identification of yellow luminescence centers in Be-doped GaN through pressure-dependent studies

    Science.gov (United States)

    Teisseyre, Henryk; Lyons, John L.; Kaminska, Agata; Jankowski, Dawid; Jarosz, Dawid; Boćkowski, Michał; Suchocki, Andrzej; Van de Walle, Chris G.

    2017-06-01

    Effective acceptor doping of wide-band-gap semiconductors is still an outstanding problem. Beryllium has been suggested as a shallow acceptor in GaN, but despite sporadic announcements, Be-induced p-type doping has never been practically realized. Be-doped GaN possesses two luminescence bands; one at 3.38 eV and a second near 2.2 eV at an energy close to that of the parasitic yellow luminescence often found in undoped GaN crystals. We have performed high hydrostatic pressure studies of bulk, Be-doped gallium nitride crystals using the diamond anvil cell technique. We observed a splitting of the yellow luminescence line under hydrostatic pressure into two components, one which is strongly dependent on applied pressure and another whose pressure dependence is more modest. Together with hybrid functional calculations, we attribute the strongly-varying component to the beryllium-oxygen complex. The second component of the yellow luminescence possesses very similar pressure behavior to the yellow luminescence observed in undoped samples grown by the same method, behavior which we find consistent with the CN acceptor. At higher pressure, we observe the vanishing of yellow luminescence and a rapid increase in luminescence intensity of the UV line. We explain this as the pressure-induced transformation of the Be-O complex from a highly localized state with large lattice relaxation to a delocalized state with limited lattice relaxation.

  9. Persistent luminescence of Eu, Mn, Dy doped calcium phosphates for in-vivo optical imaging

    Energy Technology Data Exchange (ETDEWEB)

    Rosticher, Céline [UPMC Univ Paris 06, CNRS, UMR 7574, Chimie de la Matière Condensée de Paris, Collège de France, 11 place Marcelin Berthelot, 75231 Paris Cedex 05 (France); Viana, Bruno, E-mail: bruno.viana@chimie-paristech.fr [PSL Research University, Chimie ParisTech-CNRS, Institut de Recherche de Chimie Paris, 11 rue Pierre et Marie Curie, 75005 Paris (France); Maldiney, Thomas; Richard, Cyrille [Unité de Technologies Chimiques et Biologiques pour la Santé, CNRS, UMR 8258, Paris Cedex F-75270 (France); Inserm U1022, Paris Cedex F-75270 (France); Faculté des Sciences Pharmaceutiques et Biologiques, Université Paris Descartes, Sorbonne Paris Cité, Paris Cedex F-75270 (France); Chanéac, Corinne, E-mail: corinne.chaneac@upmc.fr [UPMC Univ Paris 06, CNRS, UMR 7574, Chimie de la Matière Condensée de Paris, Collège de France, 11 place Marcelin Berthelot, 75231 Paris Cedex 05 (France)

    2016-02-15

    Biocompatible nanoparticles possessing persistent luminescence properties offer attractive possibilities for in vivo imaging applications as it allows an excitation of the sensors outside the animal before injection and a long-lasting emission of light. Here we report the development of highly biocompatible calcium phosphate nanoparticles doped with europium, Mn{sup 2+} and Ln{sup 3+} (Ln{sup 3+}=Dy{sup 3+}, Pr{sup 3+}) ions synthesized by hydrothermal route and tailored to present red-near infrared persistent luminescence after UV excitation. Nanosize biphasic HAp/β-TCP compounds with sphere and rod-shaped were obtained. Two emission bands in the red-near infrared range were observed and attributed to {sup 4}T{sub 1}→{sup 6}A{sub 1} transitions of Mn{sup 2+} ions in HAp/β-TCP. An annealing treatment in reductive atmosphere post-synthesis was essential to reveal persistent luminescence properties. Indeed, such thermal treatment allows reducing Eu{sup 3+} ions in Eu{sup 2+} ions and generating required defaults as oxygen vacancies in the crystal necessary for red emission in accordance with persistent luminescence mechanism. These nanoparticles have been tested for the first time for in vivo imaging on small animal as proof of concept of prospective highly biocompatible nanoprobes. - Highlights: • Biocompatible HAp/b-TCP nanoparticles with persistent luminescence are investigated. • Reducing step induced persistent luminescence. • Nanoparticles have been tested for the first time for in vivo imaging. • Persistent luminescence is observed after 10 min in vivo.

  10. Study of Polymeric Luminescent Blend (PC/PMMA) Doped with Europium Complex under Gamma-Iradiation

    International Nuclear Information System (INIS)

    Parra, D. F.

    2006-01-01

    Spectroscopic properties of blends formed by bisphenol-A polycarbonate (PC) and poly(methyl methacrylate) (PMMA) doped with europium in organic complex were studied. Polymeric luminescent blends are potential materials for many applications; however, little information has been reported concerning the stability under thermal and radiation conditions. Luminescent films were synthesized from europium thenoyltrifluoroacetonate at different concentrations doped in PC/PMMA blends. Films produced of the luminescent polymer blend were irradiated in a 60 C o source. Their luminescent properties, in the solid state, as well as, the thermal oxidative resistance after gamma irradiation was investigated. These systems were characterized by elemental analysis, thermogravimetry (TGA), differential scanning calorimetry (DSC) and infrared spectroscopy (FTIR). Based on TGA data, the thermal stability of PC/PMMA:(tta)3 system is higher than the polymer blend. The DSC results indicated that those new systems are chemically stables. The emission spectra of the Eu 3 +-tta complex doped in the PC/PMMA recorded at 298 and 77 K exhibited the characteristic bands arising from the 5 D 0 →7 F J transitions (J = 0-6). The luminescence intensity decreases with increasing of precursor concentration in the doped polymer obtained by chemical reaction. This result is different from that of samples obtained by physical method in melting doping. The blend was irradiated under ionizing radiation of 60 C o source. After irradiation of the luminescent films the physical properties of luminescence, thermal and oxidative stability were evaluated.(Fapesp and Cnpq financial support)

  11. A portable luminescence dating instrument

    DEFF Research Database (Denmark)

    Kook, M.H.; Murray, A.S.; Lapp, Torben

    2011-01-01

    We describe a portable luminescence reader suitable for use in remote localities in the field. The instrument weighs about 8kg and is based around a 30mm bialkali photomultiplier detecting signals through a glass filter centered on 340nm. Stimulation is by 470nm blue LEDs (24W in total) operating...

  12. Luminescence due to peptide linkage observed in L-cysteine molecules irradiated by infrared laser light

    Energy Technology Data Exchange (ETDEWEB)

    Tsujibayashi, Toru, E-mail: toru-t@cc.osaka-dent.ac.jp [Department of Physics, Osaka Dental University, 8-1 Kuzuha-hanazono, Hirakata, Osaka 573-1121 (Japan); Matsubara, Eiichi; Ichimiya, Masayoshi [Department of Physics, Osaka Dental University, 8-1 Kuzuha-hanazono, Hirakata, Osaka 573-1121 (Japan); Ohno, Nobuhito [Fundamental Electronics Research Institute, Osaka Electro-Communication University, 18-8 Hatsu-Cho, Neyagawa, Osaka 572-8530 (Japan)

    2016-01-15

    The sequence of amino acids in peptide chains consisting of proteins is the most fundamental information of living things. A direct and nondestructive method of reading is highly required as an alternative to the method based on the gene analysis. Luminescence detection is a very sensitive tool for investigating various materials. In order to find characteristic luminescence of each amino acid we study L-cysteine and L-tyrosine using UV laser of 3.36 eV with pulse duration of 1.5 ps. In addition to a common 2.66 eV band of the luminescence we have found 2.89 eV band for L-cysteine and 2.92 eV band for L-tyrosine. It can be interpreted that the side chain makes difference on the luminescence by affecting the peptide linkage or carbonyl group. - Highlights: • Luminescence from L-cysteine and L-tyrosine are studied. • Analyzing the luminescence enables to distinguish those two amino acids. • The lifetimes and the peak photon energies under UV laser excitation are presented.

  13. Multistate Luminescent Solar Concentrator "Smart" Windows

    NARCIS (Netherlands)

    Sol, Jeroen A.H.P.; Timmermans, Gilles H.; Breugel, van Abraham J.; Schenning, Albertus P.H.J.; Debije, Michael G.

    2018-01-01

    A supertwist liquid crystalline luminescent solar concentrator (LSC) "smart" window is fabricated which can be switched electrically between three states: one designed for increased light absorption and electrical generation (the "dark" state), one for transparency (the "light" state), and one for

  14. Luminescence properties of Si-containing porous matrix–PbS nanoparticle systems

    International Nuclear Information System (INIS)

    Tarasov, S. A.; Aleksandrova, O. A.; Lamkin, I. A.; Maksimov, A. I.; Maraeva, E. V.; Mikhailov, I. I.; Moshnikov, V. A.; Musikhin, S. F.; Nalimova, S. S.; Permyakov, N. V.; Spivak, Yu. M.; Travkin, P. G.

    2015-01-01

    The luminescence properties of systems that contain lead-sulfide nanoparticles deposited onto substrates fabricated from porous silicon, oxidized porous silicon, and porous (tin-oxide)–(silicon-oxide) layers are studied. It is shown that the structure and composition of the matrix induce a strong effect on the luminescence spectra of colloidal quantum dots, defining their emission wavelength

  15. Mitochondria Targetable Time-Gated Luminescence Probe for Singlet Oxygen Based on a β-Diketonate-Europium Complex.

    Science.gov (United States)

    Sun, Jingyan; Song, Bo; Ye, Zhiqiang; Yuan, Jingli

    2015-12-21

    Singlet oxygen ((1)O2) plays a key role in the photodynamic therapy (PDT) technique of neoplastic diseases. In this work, by using a 9,10-dimethyl-2-anthryl-containing β-diketone, 1,1,1,2,2-pentafluoro-5-(9',10'-dimethyl-2'-anthryl)-3,5-pentanedione (Hpfdap), as a (1)O2-recognition ligand, a novel β-diketonate-europium(III) complex that can act as a luminescence probe for (1)O2, [Eu(pfdap)3(tpy)] (tpy = 2,2',2″-terpyridine), has been designed and synthesized for the time-gated luminescence detection of (1)O2 in living cells. The complex is weakly luminescent due to the quenching effect of 9,10-dimethyl-2-anthryl groups. After reaction with (1)O2, accompanied by the formation of endoperoxides of 9,10-dimethyl-2-anthryl groups, the luminescence quenching disappears, so that the long-lived luminescence of the europium(III) complex is switched on. The complex showed highly selective luminescence response to (1)O2 with a remarkable luminescence enhancement. Combined with the time-gated luminescence imaging technique, the complex was successfully used as a luminescent probe for the monitoring of the time-dependent generation of (1)O2 in 5-aminolevulinic acid (a PDT drug) loaded HepG2 cells during the photodynamic process. In addition, by coloading the complex and a mitochondrial indicator, Mito-Tracker Green, into HepG2 cells, the specific localization of [Eu(pfdap)3(tpy)] molecules in mitochondria of HepG2 cells was demonstrated by confocal fluorescence imaging measurements.

  16. Luminescence imaging of water during irradiation of X-ray photons lower energy than Cerenkov- light threshold

    Energy Technology Data Exchange (ETDEWEB)

    Yamamoto, Seiichi; Koyama, Shuji; Komori, Masataka [Radiological and Medical Laboratory Sciences, Nagoya University Graduate School of Medicine (Japan); Toshito, Toshiyuki [Department of Proton Therapy Physics, Nagoya Proton Therapy Center, Nagoya City West Medical Center (Japan)

    2016-10-01

    Luminescence imaging of water using X-ray photon irradiation at energy lower than maximum energy of ~200 keV is thought to be impossible because the secondary electrons produced in this energy range do not emit Cerenkov- light. Contrary to this consensus assumption, we show that the luminescence imaging of water can be achieved by X-ray irradiation at energy lower than 120 keV. We placed water phantoms on a table with a conventional X-ray imaging system, and luminescence images of these phantoms were measured with a high-sensitivity, cooled charge coupled device (CCD) camera during X-ray photon irradiation at energy below 120 keV. We also carried out such imaging of an acrylic block and plastic scintillator. The luminescence images of water phantoms taken during X-ray photon irradiation clearly showed X-ray photon distribution. The intensity of the X-ray photon images of the phantom increased almost proportionally to the number of X-ray irradiations. Lower-energy X-ray photon irradiation showed lower-intensity luminescence at the deeper parts of the phantom due to the higher X-ray absorption in the water phantom. Furthermore, lower-intensity luminescence also appeared at the deeper parts of the acrylic phantom due to its higher density than water. The intensity of the luminescence for water was 0.005% of that for plastic scintillator. Luminescence imaging of water during X-ray photon irradiation at energy lower than 120 keV was possible. This luminescence imaging method is promising for dose estimation in X-ray imaging systems.

  17. Luminescence imaging of water during irradiation of X-ray photons lower energy than Cerenkov- light threshold

    Science.gov (United States)

    Yamamoto, Seiichi; Koyama, Shuji; Komori, Masataka; Toshito, Toshiyuki

    2016-10-01

    Luminescence imaging of water using X-ray photon irradiation at energy lower than maximum energy of 200 keV is thought to be impossible because the secondary electrons produced in this energy range do not emit Cerenkov- light. Contrary to this consensus assumption, we show that the luminescence imaging of water can be achieved by X-ray irradiation at energy lower than 120 keV. We placed water phantoms on a table with a conventional X-ray imaging system, and luminescence images of these phantoms were measured with a high-sensitivity, cooled charge coupled device (CCD) camera during X-ray photon irradiation at energy below 120 keV. We also carried out such imaging of an acrylic block and plastic scintillator. The luminescence images of water phantoms taken during X-ray photon irradiation clearly showed X-ray photon distribution. The intensity of the X-ray photon images of the phantom increased almost proportionally to the number of X-ray irradiations. Lower-energy X-ray photon irradiation showed lower-intensity luminescence at the deeper parts of the phantom due to the higher X-ray absorption in the water phantom. Furthermore, lower-intensity luminescence also appeared at the deeper parts of the acrylic phantom due to its higher density than water. The intensity of the luminescence for water was 0.005% of that for plastic scintillator. Luminescence imaging of water during X-ray photon irradiation at energy lower than 120 keV was possible. This luminescence imaging method is promising for dose estimation in X-ray imaging systems.

  18. Luminescence recognition of different organophosphorus pesticides by the luminescent Eu(III)–pyridine-2,6-dicarboxylic acid probe

    International Nuclear Information System (INIS)

    Azab, Hassan A.; Duerkop, Axel; Anwar, Z.M.; Hussein, Belal H.M.; Rizk, Moustafa A.; Amin, Tarek

    2013-01-01

    Highlights: ► Europium (III) luminescence quenching has been used for sensing organophosphorous pesticides. ► Four guest pesticides chlorfenvinphos, malathion, azinphos, and paraxon ethyl were used. ► A sensitive rapid, cheap direct method for the determination of the pesticides has been developed. ► The method was applied to the determination of the OPs in tap, river, mineral, and waste waters. - Abstract: Luminescence quenching of a novel long lived Eu(III)–pyridine-2,6-dicarboxylic acid probe of 1:2 stoichiometric ratio has been studied in 0.10 volume fraction ethanol–water mixture at pH 7.5 (HEPES buffer) in the presence of the organophosphorus pesticides chlorfenvinphos (P1), malathion (P2), azinphos (P3), and paraxon ethyl (P4). The luminescence intensity of Eu(III)–(PDCA) 2 probe decreases as the concentration of the pesticide increases. It was observed that the quenching due to P3 and P4 proceeds via both diffusional and static quenching processes. Direct methods for the determination of the pesticides under investigation have been developed using the luminescence quenching of Eu(III)–pyridine-2,6-dicarboxylic acid probe in solution. The linear range for determination of the selected pesticides is 1.0–35.0 μM. The detection limits were 0.24–0.55 μM for P3, P4, and P1 and 2.5 μM for P2, respectively. The binding constants (K), and thermodynamic parameters of the OPs with Eu(III)–(PDCA) 2 were evaluated. Positive and negative values of entropy (ΔS) and enthalpy (ΔH) changes for Eu(III)–(PDCA) 2 –P1 ternary complex were calculated. As the waters in this study do not contain the above mentioned OPs over the limit detectable by the method, a recovery study was carried out after the addition of the adequate amounts of the organophosphorus pesticides under investigation.

  19. Excitonic surface polaritons in luminescence from ZnTe crystals

    International Nuclear Information System (INIS)

    Brodin, M.S.; Bandura, V.M.; Matsko, M.G.

    1984-01-01

    The form and structure of reflection and exciton-polariton luminescence spectra of ZnTe crystals are studied in the region of the ground (n = 1) exciton state. The longitudinal-transverse splitting magnitude ΔE/sub LT/ is determined from the shape of the reflection spectra. A detected doublet structure of an emission band from the lower polariton branch is associated with the k-linear term. The evolution of bulk and surface polariton luminescence spectra versus temperature and wavelength of the exciting light is investigated. (author)

  20. Excitonic surface polaritons in luminescence from ZnTe crystals

    Energy Technology Data Exchange (ETDEWEB)

    Brodin, M.S.; Bandura, V.M.; Matsko, M.G. (AN Ukrainskoj SSR, Kiev. Inst. Fiziki)

    1984-10-01

    The form and structure of reflection and exciton-polariton luminescence spectra of ZnTe crystals are studied in the region of the ground (n = 1) exciton state. The longitudinal-transverse splitting magnitude ..delta..E/sub LT/ is determined from the shape of the reflection spectra. A detected doublet structure of an emission band from the lower polariton branch is associated with the k-linear term. The evolution of bulk and surface polariton luminescence spectra versus temperature and wavelength of the exciting light is investigated.

  1. Functional morphology of the luminescence system of Siphamia versicolor (Perciformes: Apogonidae), a bacterially luminous coral reef fish.

    Science.gov (United States)

    Dunlap, Paul V; Nakamura, Masaru

    2011-08-01

    Previous studies of the luminescence system of Siphamia versicolor (Perciformes: Apogonidae) identified a ventral light organ, reflector, lens, duct, and a ventral diffuser extending from the throat to the caudal peduncle. The control and function of luminescence in this and other species of Siphamia, however, have not been defined. Morphological examination of fresh and preserved specimens identified additional components of the luminescence system involved in control and ventral emission of luminescence, including a retractable shutter over the ventral face of the light organ, contiguity of the ventral diffuser from the caudal peduncle to near the chin, and transparency of the bones and other tissues of the lower jaw. The shutter halves retract laterally, allowing the ventral release of light, and relax medially, blocking ventral light emission; topical application of norepinephrine to the exposed light organ resulted in retraction of the shutter halves, which suggests that operation of the shutter is under neuromuscular control. The extension of the diffuser to near the chin and transparency of the lower jaw allow a uniform emission of luminescence over the entire ventrum of the fish. The live aquarium-held fish were found to readily and consistently display ventral luminescence. At twilight, the fish left the protective association with their longspine sea urchin, Diadema setosum, and began to emit ventral luminescence and to feed on zooplankton. Ventral luminescence illuminated a zone below and around the fish, which typically swam close to the substrate. Shortly after complete darkness, the fish stopped feeding and emitting luminescence. These observations suggest that S. versicolor uses ventral luminescence to attract and feed on zooplankton from the reef benthos at twilight. Ventral luminescence may allow S. versicolor to exploit for feeding the gap at twilight in the presence of potential predators as the reef transitions from diurnally active to

  2. Infrared stimulated luminescence dating of an Eemian (MIS 5e) site in Denmark using K-feldspar

    DEFF Research Database (Denmark)

    Buylaert, Jan-Pieter; Huot, Sebastian; Murray, Andrew S.

    2011-01-01

    Infrared stimulated luminescence (IRSL) dating of K-feldspars may be an alternative to quartz optically stimulated luminescence (OSL) dating when the quartz OSL signal is too close to saturation or when the quartz luminescence characteristics are unsuitable. In this paper, Eemian (MIS 5e) coastal...

  3. Luminescence detection of phase transitions in crystals and nanoparticle inclusions

    International Nuclear Information System (INIS)

    Townsend, P. D.; Yang, B.; Wang, Y.

    2008-01-01

    Luminescence measurements are extremely sensitive to variations in structural environment and thus have the potential to probe distortions of fluorescence sites. Changes can be monitored via luminescence efficiency, emission spectra or excited state lifetimes and these factors are influenced by the local neighbourhood around the emission site, and therefore by structure, composition, pressure and temperature. A rarely exploited approach for condensed matter has been to use the changes in luminescence responses during heating or cooling of a material to provide a rapid survey to detect the presence of phase transitions. One can often differentiate between bulk and surface effects by contrasting results from radioluminescence for bulk responses, and cathodoluminescence or photoluminescence for surface effects. One expects that discontinuous changes in optical parameters occur during temperature changes through phase transitions of insulating materials. In practice, optical signals also exist from surface states of fullerenes and high temperature superconductors etc which identify the presence of structural or superconducting transitions. Numerous examples are cited which match standard documented transitions. Interestingly many examples show the host signals are strongly sensitive to impurity phase transitions from inclusions such as nanoparticles of water, N 2 , O 2 or CO 2 . Recent luminescence data reveal many examples of new transitions, hysteresis and irreversible changes. The signals equally respond to relaxations of a structure and surprisingly indicate that in some materials, such as SrTiO 3 or ZnO, ion implantation of the surface triggers relaxations and phase changes throughout the bulk of the material. Luminescence routes to detect phase transitions are powerful tools but have a tiny literature and so the subject is ideal for rapid exploitation and development. (Author)

  4. Visible luminescence peculiar to sintered silica nanoparticles: Spectral and decay properties

    Energy Technology Data Exchange (ETDEWEB)

    Vaccaro, L. [Dipartimento di Fisica e Chimica, Università di Palermo, Via Archirafi 36, I-90123 Palermo (Italy); Cannas, M., E-mail: marco.cannas@unipa.it [Dipartimento di Fisica e Chimica, Università di Palermo, Via Archirafi 36, I-90123 Palermo (Italy); Cangialosi, C. [Dipartimento di Fisica e Chimica, Università di Palermo, Via Archirafi 36, I-90123 Palermo (Italy); Laboratoire H. Curien, UMR CNRS 5516, Université St-Etienne, St-Etienne F-42000 (France); Spallino, L.; Gelardi, F.M. [Dipartimento di Fisica e Chimica, Università di Palermo, Via Archirafi 36, I-90123 Palermo (Italy)

    2015-10-15

    We report that the sintering at 1000 °C of silica nanoparticles (an average diameter of 14 nm) produces a transparent sample that exhibits a bright visible emission under UV excitation. The use of time resolved luminescence spectroscopy and a tunable laser source allows us to single out three contributions centered at 1.96 eV, 2.41 eV and 3.43 eV. The excitation spectra of these emissions evidence bell shaped bands consistent with transitions between localized defects’ states. For each emission we study the intensity and the lifetime in the temperature range from 300 K down to 10 K, thus evidencing the competition between radiative and non-radiative processes in the optical cycle of luminescent centers. The comparison with the luminescence properties of silica, both nanoparticles and bulk, points out that the observed emissions are peculiar to the sintered silica network. - Highlights: • Solid-phase sintering at 1000 °C of silica nanoparticles produces a transparent sample. • Sintered silica nanoparticles emit a bright luminescence under UV excitation. • Three emissions, centered around 2.0 V, 2.4 eV and 3.4 eV, are distinguished on the basis of the excitation and decay properties. • The observed excitation/emission bands originate from localized defect states peculiar to the sintered silica network. • The luminescence efficiency decreases with temperature due to the activation of non-radiative channels.

  5. MO-A-BRB-00: TG191: Clinical Use of Luminescent Dosimeters

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2016-06-15

    This presentation will highlight the upcoming TG-191 report: Clinical Use of Luminescent Dosimeters. Luminescent dosimetry based on TLD and OSLD is a practical, accurate, and precise technique for point dosimetry in medical physics applications. The charges of Task Group 191 were to detail the methodologies for practical and optimal luminescent dosimetry in a clinical setting. This includes (1) To review the variety of TLD/OSL materials available, including features and limitations of each. (2) To outline the optimal steps to achieve accurate and precise dosimetry with luminescent detectors and to evaluate the uncertainty induced when less rigorous procedures are used. (3) To develop consensus guidelines on the optimal use of luminescent dosimeters for clinical practice. (4) To develop guidelines for special medically relevant uses of TLDs/OSLs (e.g., mixed field i.e. photon/neutron dosimetry, particle beam dosimetry, skin dosimetry). While this report provides general guidelines for arbitrary TLD and OSLD processes, the report, and therefore this presentation, provide specific guidance for TLD-100 (LiF:Ti,Mg) and nanoDot (Al2O3:C) dosimeters because of their prevalence in clinical practice. Learning Objectives: Understand the available dosimetry systems, and basic theory of their operation Understand the range of dose determination methodologies and the uncertainties associated with them Become familiar with special considerations for TLD/OSLD relevant for special clinical situations Learn recommended commissioning and QA procedures for these dosimetry systems.

  6. MO-A-BRB-01: TG191: Clinical Use of Luminescent Dosimeters

    Energy Technology Data Exchange (ETDEWEB)

    Kry, S. [UT MD Anderson Cancer Center (United States)

    2016-06-15

    This presentation will highlight the upcoming TG-191 report: Clinical Use of Luminescent Dosimeters. Luminescent dosimetry based on TLD and OSLD is a practical, accurate, and precise technique for point dosimetry in medical physics applications. The charges of Task Group 191 were to detail the methodologies for practical and optimal luminescent dosimetry in a clinical setting. This includes (1) To review the variety of TLD/OSL materials available, including features and limitations of each. (2) To outline the optimal steps to achieve accurate and precise dosimetry with luminescent detectors and to evaluate the uncertainty induced when less rigorous procedures are used. (3) To develop consensus guidelines on the optimal use of luminescent dosimeters for clinical practice. (4) To develop guidelines for special medically relevant uses of TLDs/OSLs (e.g., mixed field i.e. photon/neutron dosimetry, particle beam dosimetry, skin dosimetry). While this report provides general guidelines for arbitrary TLD and OSLD processes, the report, and therefore this presentation, provide specific guidance for TLD-100 (LiF:Ti,Mg) and nanoDot (Al2O3:C) dosimeters because of their prevalence in clinical practice. Learning Objectives: Understand the available dosimetry systems, and basic theory of their operation Understand the range of dose determination methodologies and the uncertainties associated with them Become familiar with special considerations for TLD/OSLD relevant for special clinical situations Learn recommended commissioning and QA procedures for these dosimetry systems.

  7. MO-A-BRB-01: TG191: Clinical Use of Luminescent Dosimeters

    International Nuclear Information System (INIS)

    Kry, S.

    2016-01-01

    This presentation will highlight the upcoming TG-191 report: Clinical Use of Luminescent Dosimeters. Luminescent dosimetry based on TLD and OSLD is a practical, accurate, and precise technique for point dosimetry in medical physics applications. The charges of Task Group 191 were to detail the methodologies for practical and optimal luminescent dosimetry in a clinical setting. This includes (1) To review the variety of TLD/OSL materials available, including features and limitations of each. (2) To outline the optimal steps to achieve accurate and precise dosimetry with luminescent detectors and to evaluate the uncertainty induced when less rigorous procedures are used. (3) To develop consensus guidelines on the optimal use of luminescent dosimeters for clinical practice. (4) To develop guidelines for special medically relevant uses of TLDs/OSLs (e.g., mixed field i.e. photon/neutron dosimetry, particle beam dosimetry, skin dosimetry). While this report provides general guidelines for arbitrary TLD and OSLD processes, the report, and therefore this presentation, provide specific guidance for TLD-100 (LiF:Ti,Mg) and nanoDot (Al2O3:C) dosimeters because of their prevalence in clinical practice. Learning Objectives: Understand the available dosimetry systems, and basic theory of their operation Understand the range of dose determination methodologies and the uncertainties associated with them Become familiar with special considerations for TLD/OSLD relevant for special clinical situations Learn recommended commissioning and QA procedures for these dosimetry systems.

  8. MO-A-BRB-00: TG191: Clinical Use of Luminescent Dosimeters

    International Nuclear Information System (INIS)

    2016-01-01

    This presentation will highlight the upcoming TG-191 report: Clinical Use of Luminescent Dosimeters. Luminescent dosimetry based on TLD and OSLD is a practical, accurate, and precise technique for point dosimetry in medical physics applications. The charges of Task Group 191 were to detail the methodologies for practical and optimal luminescent dosimetry in a clinical setting. This includes (1) To review the variety of TLD/OSL materials available, including features and limitations of each. (2) To outline the optimal steps to achieve accurate and precise dosimetry with luminescent detectors and to evaluate the uncertainty induced when less rigorous procedures are used. (3) To develop consensus guidelines on the optimal use of luminescent dosimeters for clinical practice. (4) To develop guidelines for special medically relevant uses of TLDs/OSLs (e.g., mixed field i.e. photon/neutron dosimetry, particle beam dosimetry, skin dosimetry). While this report provides general guidelines for arbitrary TLD and OSLD processes, the report, and therefore this presentation, provide specific guidance for TLD-100 (LiF:Ti,Mg) and nanoDot (Al2O3:C) dosimeters because of their prevalence in clinical practice. Learning Objectives: Understand the available dosimetry systems, and basic theory of their operation Understand the range of dose determination methodologies and the uncertainties associated with them Become familiar with special considerations for TLD/OSLD relevant for special clinical situations Learn recommended commissioning and QA procedures for these dosimetry systems.

  9. Mesoporous material grafted with luminescent molecules for the design of selective metal ion chemosensor

    International Nuclear Information System (INIS)

    Zhang Huidong; Zhang Ping; Ye Kaiqi; Sun Yinghui; Jiang Shimei; Wang Yue; Pang Wenqin

    2006-01-01

    Luminescent Schiff-base groups have been successfully grafted on the surface of mesoporous material MCM-48. The grafted Schiff-base groups were employed to prepare luminescent Schiff-base-Zn complex that was covalently bound to the MCM-48 surface. These luminescent mesoporous materials were characterized with X-ray, UV-VIS and emission spectroscopic methods. Experimental results demonstrated that MCM-48 modified with functional groups exhibited novel luminescent property. The chemosensing property of modified MCM-48 sample was investigated. It was demonstrated that the fluorescence of MCM-48 solid with Schiff-base groups could be completely quenched by Cu 2+ cation and this mesoporous material was suitable for sensing Cu 2+ cation in aqueous media

  10. Novel dental dynamic depth profilometric imaging using simultaneous frequency-domain infrared photothermal radiometry and laser luminescence

    Science.gov (United States)

    Nicolaides, Lena; Mandelis, Andreas

    2000-01-01

    A high-spatial-resolution dynamic experimental imaging setup, which can provide simultaneous measurements of laser- induced frequency-domain infrared photothermal radiometric and luminescence signals from defects in teeth, has been developed for the first time. The major findings of this work are: (1) radiometric images are complementary to (anticorrelated with) luminescence images, as a result of the nature of the two physical signal generation processes; (2) the radiometric amplitude exhibits much superior dynamic (signal resolution) range to luminescence in distinguishing between intact and cracked sub-surface structures in the enamel; (3) the radiometric signal (amplitude and phase) produces dental images with much better defect localization, delineation, and resolution; (4) radiometric images (amplitude and phase) at a fixed modulation frequency are depth profilometric, whereas luminescence images are not; and (5) luminescence frequency responses from enamel and hydroxyapatite exhibit two relaxation lifetimes, the longer of which (approximately ms) is common to all and is not sensitive to the defect state and overall quality of the enamel. Simultaneous radiometric and luminescence frequency scans for the purpose of depth profiling were performed and a quantitative theoretical two-lifetime rate model of dental luminescence was advanced.

  11. Luminescence and electrification in a flow of dielectric liquids through narrow channels

    Science.gov (United States)

    Margulis, M. A.; Pil'Gunov, V. N.

    2009-08-01

    Blue-violet luminescence was observed in a mineral oil, which appeared under hydrodynamic cavitation conditions in a channel orifice 1 mm in diameter in a transparent throttling device at inlet pressures higher than 2 MPa. The appearance of electric pulses when a dielectric liquid flew through a thin channel orifice was observed much earlier than luminescence arose. A device for continuously scanning electric potential along a flow without disturbing it was developed. According to the oscillograms obtained, the electric signal was high-frequency, could not be synchronized, and its separate peaks reached 1000 mV. Light emission flux decreased as the temperature of the liquid increased to 30-35°C and inlet pressure grew. The appearance of luminescence and its intensity depended on the sharpness of the entrance edge of the throttle. Studies of hydrodynamic luminescence revealed hysteresis of light emission. A mechanism of localized light emission based on an important role played by electrokinetic phenomena was suggested.

  12. Ion beam induced luminescence from diamond using an MeV ion microprobe

    Energy Technology Data Exchange (ETDEWEB)

    Bettiol, A.A.; Jamieson, D. N.; Prawer, S.; Allen, M.G. [Melbourne Univ., Parkville, VIC (Australia). School of Physics

    1993-12-31

    Analysis of the luminescence induced by a MeV ion beam offers the potential to provide useful information about the chemical properties of atoms in crystals to complement the information provided by more traditional Ion Beam Analysis (IBA) such as Rutherford Backscattering Spectrometry (RBS), ion channeling and Particle Induced X-ray Emission (PIXE). Furthermore, the large penetration depth of the MeV ion beam offers several advantages over the relatively shallow penetration of keV electrons typically employed in cathodoluminescence. An Ion Beam Induced Luminescence (IBIL) detection system was developed for the Melbourne microprobe that allows the spatial mapping of the luminescence signal along with the signals from RBS and PIXE. Homoepitaxial diamond growth has been studied and remarkable shifts in the characteristic blue luminescence of diamond towards the green were observed in the overgrowth. This has been tentatively identified as being due to transition metal inclusions in the epitaxial layers. 8 refs., 2 refs.

  13. Ion beam induced luminescence from diamond using an MeV ion microprobe

    Energy Technology Data Exchange (ETDEWEB)

    Bettiol, A A; Jamieson, D N; Prawer, S; Allen, M G [Melbourne Univ., Parkville, VIC (Australia). School of Physics

    1994-12-31

    Analysis of the luminescence induced by a MeV ion beam offers the potential to provide useful information about the chemical properties of atoms in crystals to complement the information provided by more traditional Ion Beam Analysis (IBA) such as Rutherford Backscattering Spectrometry (RBS), ion channeling and Particle Induced X-ray Emission (PIXE). Furthermore, the large penetration depth of the MeV ion beam offers several advantages over the relatively shallow penetration of keV electrons typically employed in cathodoluminescence. An Ion Beam Induced Luminescence (IBIL) detection system was developed for the Melbourne microprobe that allows the spatial mapping of the luminescence signal along with the signals from RBS and PIXE. Homoepitaxial diamond growth has been studied and remarkable shifts in the characteristic blue luminescence of diamond towards the green were observed in the overgrowth. This has been tentatively identified as being due to transition metal inclusions in the epitaxial layers. 8 refs., 2 refs.

  14. Hydrothermal synthesis, characterization and luminescent ...

    Indian Academy of Sciences (India)

    that nanoparticles have cylindrical shape and crystalline nature of nanoparticles was confirmed by SAED patterns. Down- conversion (DC) luminescent properties of doped NaLaF4 were also .... Figure 1 shows the XRPD patterns of undoped NaLaF4 and .... which can be assigned to the transitions from the 7F6 ground.

  15. Biosynthesis of myristic acid in luminescent bacteria. [Vibrio harveyi

    Energy Technology Data Exchange (ETDEWEB)

    Byers, D.M.

    1987-05-01

    In vivo pulse-label studies have demonstrated that luminescent bacteria can provide myritic acid (14:0) required for the synthesis of the luciferase substrate myristyl aldehyde. Luminescent wild type Vibrio harveyi incubated with (/sup 14/C) acetate in a nutrient-depleted medium accumulated substantial tree (/sup 14/C)fatty acid (up to 20% of the total lipid label). Radio-gas chromatography revealed that > 75% of the labeled fatty acid is 14:0. No free fatty acid was detected in wild type cells labeled prior to the development of bioluminescence in the exponential growth phase, or in a dark mutant of V. harveyi (mutant M17) that requires exogenous 14:0 for light emission. The preferential accumulation of 14:0 was not observed when wild type cells were labeled with (/sup 14/C)acetate in regular growth medium. Moreover, all V. harveyi strains exhibited similar fatty acid mass compositions regardless of the state of bioluminescence. Since earlier work has shown that a luminescence-related acyltransferase (defective in the M17 mutant) can catalyze the deacylation of fatty acyl-acyl carrier protein in vitro, the present results are consistent with a model in which this enzyme diverts 14:0 to the luminescence system during fatty acid biosynthesis. Under normal conditions, the supply of 14:0 by this pathway is tightly regulated such that bioluminescence development does not significantly alter the total fatty acid composition.

  16. Influence of excitonic effects on luminescence quantum yield in silicon

    Energy Technology Data Exchange (ETDEWEB)

    Sachenko, A.V.; Kostylyov, V.P.; Vlasiuk, V.M. [V. Lashkaryov Institute of Semiconductor Physics, NAS of Ukraine, 41 prospect Nauky, 03028 Kyiv (Ukraine); Sokolovskyi, I.O., E-mail: isokolovskyi@mun.ca [V. Lashkaryov Institute of Semiconductor Physics, NAS of Ukraine, 41 prospect Nauky, 03028 Kyiv (Ukraine); Department of Physics and Physical Oceanography, Memorial University of Newfoundland, St. John' s, NL, A1B 3X7 Canada (Canada); Evstigneev, M. [Department of Physics and Physical Oceanography, Memorial University of Newfoundland, St. John' s, NL, A1B 3X7 Canada (Canada)

    2017-03-15

    Nonradiative exciton lifetime in silicon is determined by comparison of the experimental and theoretical curves of bulk minority charge carriers lifetime on doping and excitation levels. This value is used to analyze the influence of excitonic effects on internal luminescence quantum yield at room temperature, taking into account both nonradiative and radiative exciton lifetimes. A range of Shockley-Hall-Reed lifetimes is found, where excitonic effects lead to an increase of internal luminescence quantum yield.

  17. Optical and luminescent properties of the lead and barium molybdates

    Energy Technology Data Exchange (ETDEWEB)

    Spassky, D.A. E-mail: dima@opts.phys.msu.ru; Ivanov, S.N.; Kolobanov, V.N.; Mikhailin, V.V.; Zemskov, V.N.; Zadneprovski, B.I.; Potkin, L.I

    2004-12-01

    Time-resolved luminescence as well as excitation and reflectivity spectra of the oriented lead and barium molybdate single crystals were studied using synchrotron radiation. Features in reflectivity spectra in the fundamental absorption region were analyzed. The contribution of electronic states of lead cation to the formation of the bandgap in PbMoO{sub 4} is supposed. The role of lead states in the intrinsic luminescence of PbMoO{sub 4} is discussed.

  18. The double luminescence of Color Centers

    International Nuclear Information System (INIS)

    Baldacchini, Giuseppe

    2015-01-01

    An experiment on the luminescence of Color Centers (CCs) carried out in 1987 at the ENEA Laboratories in Frascati had a negative result, but subsequent investigations showed that it was not a failure but rather a discovery of a new phenomenon. Since the coming of lasers, CCs in alkali halides have been successfully used as optically active materials, in particular FA Centers. One of these centers, well known for its medium infrared laser emission at 77 K, cooled further to 2 K emitted in the near infrared and without laser effect. Further investigations showed that the double luminescence was a fundamental property unknown until that time. This important discovery was achieved in Frascati because of the existence since 1973 of a solid and extensive expertise in the field of CCs, which continued over time and later on applied to the modern miniaturized photonic devices [it

  19. Two types of fundamental luminescence of ionization-passive electrons and holes in optical dielectrics—Intraband-electron and interband-hole luminescence (theoretical calculation and comparison with experiment)

    Science.gov (United States)

    Vaisburd, D. I.; Kharitonova, S. V.

    1997-11-01

    A short high-power pulse of ionizing radiation creates a high concentration of nonequilibrium electrons and holes in a dielectric. They quickly lose their energy, generating a multiplicity of secondary quasiparticles: electron—hole pairs, excitons, plasmons, phonons of all types, and others. When the kinetic energy of an electron becomes less that some value EΔ≈(1.3-2)Eg it loses the ability to perform collisional ionization and electron excitations of the dielectric medium. Such an electron is said to be ionization-passive. It relaxes to the bottom of the lower conduction band by emitting phonons. Similarly a hole becomes ionization-passive when it “floats up” above some level EH and loses the ability for Auger ionization of the dielectric medium. It continues to float upward to the ceiling of the upper valance band only by emitting phonons. The concentrations of ionization-passive electrons and holes are larger by several orders of magnitude than those of the active electrons and holes and consequently make of a far larger contribution to many kinetic processes such as luminescence. Intraband and interband quantum transitions make the greatest contribution to the fundamental (independent of impurities and intrinsic defects) electromagnetic radiation of ionization-passive electrons and holes. Consequently the brightest types of purely fundamental luminescence of strongly nonequilibrium electrons and holes are intraband and interband luminescence. These forms of luminescence, discovered relatively recently, carry valuable information on the high-energy states of the electrons in the conduction band and of the holes in the valence band of a dielectric. Experimental investigations of these types of luminescence were made, mainly on alkali halide crystals which were excited by nanoseconal pulses of high-current-density electrons and by two-photon absorption of the ultraviolet harmonics of pulsed laser radiation beams of nanosecond and picosecond duration. The

  20. Anti-Stokes Luminescence in High Quality Quantum Wells

    Science.gov (United States)

    Vinattieri, A.; Bogani, F.; Miotto, A.; Ceccherini, S.

    1997-11-01

    We present a detailed investigation of the anti-Stokes (AS) luminescence which originates from exciton recombination when below gap excitation is used, in a set of high quality quantum well structures. We observe strong excitonic resonances in the AS signal as measured from photoluminescence and photoluminescence excitation spectra. We demonstrate that neither the electromagnetic coupling between the wells nor the morphological disorder can explain this up-conversion effect. Time-resolved luminescence data after ps excitation and fs correlation spectroscopy results provide clear evidence of the occurrence of a two-step absorption which is assisted by the exciton population resonantly excited by the first photon.

  1. Sensitization effects of supramolecular assemblies on the luminescence of terbium-ion prulifloxacin complexes

    Energy Technology Data Exchange (ETDEWEB)

    Wang Hong; Yi Chongyue; Li Xue; Fang Fang [School of Chemistry and Chemical Engineering, Huazhong University of Science and Technology, Wuhan 430074 (China); Yang Yajiang, E-mail: yjyang@mail.hust.edu.c [School of Chemistry and Chemical Engineering, Huazhong University of Science and Technology, Wuhan 430074 (China)

    2011-04-15

    Luminescence enhancement of terbium-ion prulifloxacin complexes (Tb(III)-PUFX) in supramolecular hydrogels formed by assembly of 1,3:2,4-di-O-benzylidene-D-sorbitol (DBS) was investigated by steady-state fluorescence, varying temperature fluorescence and time-resolved fluorescence. The luminescence images show that Tb(III)-PUFX were dispersed in the DBS gels. The luminescence intensity of Tb(III)-PUFX in the DBS gels was significantly increased in comparison with that in corresponding aqueous solutions. The varying temperature fluorescent spectra show that the luminescence intensity of Tb(III)-PUFX decreased with an increase in the temperature. This implies that the luminescence enhancement of Tb(III)-PUFX is related to the dissociation and the formation of the DBS assemblies. Time-resolved fluorescence measurements show slower rotational motion in DBS gels in comparison with that in the corresponding aqueous solutions. This may be ascribed to a unique microstructure of three-dimensional network formed by DBC aggregates, resulting in deactivation of the nonradiative relaxation. The images of field emission scanning electron microscopy and polarized optical microscopy indicate that the morphology of the DBS assemblies was not influenced upon addition of Tb(III)-PUFX to the DBS gels.

  2. Luminescence of CdSe/ZnS quantum dots infiltrated into an opal matrix

    International Nuclear Information System (INIS)

    Gruzintsev, A. N.; Emelchenko, G. A.; Masalov, V. M.; Yakimov, E. E.; Barthou, C.; Maitre, A.

    2009-01-01

    The effect of the photonic band gap in the photonic crystal, the synthesized SiO 2 opal with embedded CdSe/ZnS quantum dots, on its luminescence in the visible spectral region is studied. It is shown that the position of the photonic band gap in the luminescence and reflectance spectra for the infiltrated opal depends on the diameter of the constituent nanospheres and on the angle of recording the signal. The optimal conditions for embedding the CdSe/ZnS quantum dots from the solution into the opal matrix are determined. It is found that, for the opal-CdSe/ZnS nanocomposites, the emission intensity decreases and the luminescence decay time increases in the spatial directions, in which the spectral positions of the photonic band gap and the luminescence peak of the quantum dots coincide.

  3. Fingermark detection on non-porous and semi-porous surfaces using YVO4:Er,Yb luminescent upconverting particles.

    Science.gov (United States)

    Ma, Rongliang; Shimmon, Ronald; McDonagh, Andrew; Maynard, Philip; Lennard, Chris; Roux, Claude

    2012-04-10

    This article describes the use of an anti-Stokes luminescent material (upconverter), yttrium vanadate doped with ytterbium and erbium (YVO(4):Er,Yb), for the development of latent fingermarks on a range of non-porous surfaces. Anti-Stokes luminescent materials emit light at shorter wavelengths than the excitation wavelength. This property is unusual in both natural and artificial materials commonly found as exhibits in forensic science casework. As a result, fingermark detection techniques based on anti-Stokes luminescence are potentially extremely sensitive and selective. Latent fingermarks on non-luminescent and inherently luminescent substrates, including Australian polymer banknotes (a well-known 'difficult' surface), were developed with YVO(4):Er,Yb by dry powder and wet powder techniques. The effectiveness of YVO(4):Er,Yb for fingermark detection was compared with that of cyanoacrylate fuming and of sodium yttrium tetrafluoride doped with ytterbium and erbium (NaYF(4):Er,Yb). The results illustrate some benefit of luminescent up-converting phosphors over traditional luminescence techniques for the detection of latent fingermarks. Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.

  4. Luminescent properties of europium different-ligand complexes with cyclic. beta. -diketones and diantipyrylalkanes

    Energy Technology Data Exchange (ETDEWEB)

    Ul' yanova, T M; Gerasimenko, G N; Tishchenko, M A; Vitkun, R A [AN Ukrainskoj SSR, Odessa. Fiziko-Khimicheskij Inst.

    1983-03-01

    Using luminescence method different-ligand complexing of europium ions with diantipyrylalkanes and cyclic ..beta..-diketones: 2-acetyl- and 2-benzoyl-1.3-indandions, has been studied. The optimum conditions of the formation of different-ligand complexes and the ratio of components in it are determined. Effect of alien lanthanides and diantipyrylmethane derivatives on the luminescence intensity of europium complexes is clarified. A correlation between the ratio of the luminescence intensity bands of europium complexes and the values of oscillator strengths of supersensitive transitions of neodymium and erbium absorption bands is established.

  5. Visible luminescence in polyaniline/(gold nanoparticle) composites

    Energy Technology Data Exchange (ETDEWEB)

    Santos, Renata F. S. [Universidade Federal de Pernambuco, Pos-Graduacao em Ciencia de Materiais (Brazil); Andrade, Cesar A. S. [Universidade Federal de Pernambuco, Departamento de Bioquimica (Brazil); Santos, Clecio G. dos [Instituto de Educacao, Ciencia e Tecnologia de Pernambuco (Brazil); Melo, Celso P. de, E-mail: celso@df.ufpe.br [Universidade Federal de Pernambuco, Pos-Graduacao em Ciencia de Materiais (Brazil)

    2013-01-15

    We describe the use of solution chemistry methods to prepare polyaniline/(gold nanoparticles)-PANI/AuNPs-composites as colloidal particles that exhibit an intense green fluorescence after excitation in the ultraviolet region. Measurements of the relative fluorescence quantum yield indicate that the intensity of the observed luminescence of these nanocomposites is a few orders of magnitude higher than the corresponding fluorescence of either the isolated polymer or the pure AuNPs. Hence, cooperative effects between the conducting polymer chains and the metallic particles must dominate the emission behavior of these materials. Transmission electron microscopy reveals the existence of metal nanoparticle aggregates with sizes in the 2-3 nm range dispersed in the polymer matrix. By implementing an experimental planning, we have been able to change the preparation parameters so as to vary in a controlled manner the intensity and the profile of the luminescence spectrum as well as the size and aggregation characteristics of the colloidal particles. We also show that when the pH of the medium is varied, the dielectric properties (such as the degree of conductivity) of the PANI/AuNPs colloidal solutions and the intensity of their luminescence change in a consistent manner. Due to the polycation nature of the doped PANI chains, we suggest that these composites may find interesting applications as fluorescent markers of biologic molecules.

  6. Plasma luminescence feedback control system for precise ultrashort pulse laser tissue ablation

    Science.gov (United States)

    Kim, Beop-Min; Feit, Michael D.; Rubenchik, Alexander M.; Gold, David M.; Darrow, Christopher B.; Marion, John E., II; Da Silva, Luiz B.

    1998-05-01

    Plasma luminescence spectroscopy was used for precise ablation of bone tissue without damaging nearby soft tissue using an ultrashort pulse laser. Strong contrast of the luminescence spectra between bone marrow and spinal cord provided the real time feedback control so bone tissue is selectively ablated while preserving the spinal cord.

  7. Luminescent Solar Concentrators with Fibre Geometry

    NARCIS (Netherlands)

    Edelenbosch, O.Y.; Fisher, M.; Patrignani, L.; Sark, W.G.J.H.M. van; Chatten, A.J.

    2013-01-01

    The potential of a fibre luminescent solar concentrator has been explored by means of both analytical and ray-tracing techniques. Coated fibres have been found to be more efficient than homogeneously doped fibres, at low absorption. For practical fibres concentration is predicted to be linear

  8. Luminescent Polymer Electrolyte Composites Using Silica Coated-Y2O3:Eu as Fillers

    Directory of Open Access Journals (Sweden)

    Mikrajuddin Abdullah

    2003-05-01

    Full Text Available Luminescent polymer electrolyte composites composed of silica coated Y2O3:Eu in polyethylene glycol (PEG matrix has been produced by initially synthesizing silica coated Y2O3:Eu and mixing with polyethylene glycol in a lithium salt solution. High luminescence intensity at round 600 nm contributed by electron transitions in Eu3+ (5D0 -> 7F0, 5D0 -> 7F1, and 5D0 -> 7F3 transitions were observed. The measured electrical conductivity was comparable to that reported for polymer electrolyte composites prepared using passive fillers (non luminescent. This approach is therefore promising for production of high intensity luminescent polymer electrolyte composites for use in development of hybrid battery/display.

  9. Instability of Yb3+ and Pr3+ low-symmetry luminescence centers in gallium phosphide

    International Nuclear Information System (INIS)

    Kasatkin, V.A.

    1985-01-01

    The stability of γb 3+ and Pr 3+ low-symmetry luminescence centers formed in gallium phosphide during quenching were studied in the process of durable storage and annealing. Observation of the Yb 3+ and Pr 3+ centrer states was accomplished by the photoluminescence spectra at 18 K. It has been established that annealing in the dark under normal conditions results in a reduced integral luminescence intensity of all low-symmetry Yb 3+ and Pr 3+ centers. Annealing of quenched GaP and GaP saples at 400 K results in complete disappearance of intracenter luminescence of Pr 3+ and low-symmetry Yb 3+ centers. Decomposition during storage and low anealing temperature point to the instability of low-symmetry centers of Pr 3+ and Yb 3+ luminescence

  10. Cherenkov luminescence measurements with digital silicon photomultipliers: a feasibility study

    Energy Technology Data Exchange (ETDEWEB)

    Ciarrocchi, Esther; Belcari, Nicola; Guerra, Alberto Del [Department of Physics, University of Pisa, Pisa (Italy); INFN, section of Pisa, Pisa (Italy); Cherry, Simon R. [Department of Biomedical Engineering, University of California, Davis, CA (United States); Lehnert, Adrienne; Hunter, William C. J.; McDougald, Wendy; Miyaoka, Robert S.; Kinahan, Paul E. [Department of Radiology, University of Washington, Seattle, WA (United States)

    2015-11-16

    A feasibility study was done to assess the capability of digital silicon photomultipliers to measure the Cherenkov luminescence emitted by a β source. Cherenkov luminescence imaging (CLI) is possible with a charge coupled device (CCD) based technology, but a stand-alone technique for quantitative activity measurements based on Cherenkov luminescence has not yet been developed. Silicon photomultipliers (SiPMs) are photon counting devices with a fast impulse response and can potentially be used to quantify β-emitting radiotracer distributions by CLI. In this study, a Philips digital photon counting (PDPC) silicon photomultiplier detector was evaluated for measuring Cherenkov luminescence. The PDPC detector is a matrix of avalanche photodiodes, which were read one at a time in a dark count map (DCM) measurement mode (much like a CCD). This reduces the device active area but allows the information from a single avalanche photodiode to be preserved, which is not possible with analog SiPMs. An algorithm to reject the noisiest photodiodes and to correct the measured count rate for the dark current was developed. The results show that, in DCM mode and at (10–13) °C, the PDPC has a dynamic response to different levels of Cherenkov luminescence emitted by a β source and transmitted through an opaque medium. This suggests the potential for this approach to provide quantitative activity measurements. Interestingly, the potential use of the PDPC in DCM mode for direct imaging of Cherenkov luminescence, as a opposed to a scalar measurement device, was also apparent. We showed that a PDPC tile in DCM mode is able to detect and image a β source through its Cherenkov radiation emission. The detector’s dynamic response to different levels of radiation suggests its potential quantitative capabilities, and the DCM mode allows imaging with a better spatial resolution than the conventional event-triggered mode. Finally, the same acquisition procedure and data processing could

  11. Cherenkov luminescence measurements with digital silicon photomultipliers: a feasibility study

    International Nuclear Information System (INIS)

    Ciarrocchi, Esther; Belcari, Nicola; Guerra, Alberto Del; Cherry, Simon R.; Lehnert, Adrienne; Hunter, William C. J.; McDougald, Wendy; Miyaoka, Robert S.; Kinahan, Paul E.

    2015-01-01

    A feasibility study was done to assess the capability of digital silicon photomultipliers to measure the Cherenkov luminescence emitted by a β source. Cherenkov luminescence imaging (CLI) is possible with a charge coupled device (CCD) based technology, but a stand-alone technique for quantitative activity measurements based on Cherenkov luminescence has not yet been developed. Silicon photomultipliers (SiPMs) are photon counting devices with a fast impulse response and can potentially be used to quantify β-emitting radiotracer distributions by CLI. In this study, a Philips digital photon counting (PDPC) silicon photomultiplier detector was evaluated for measuring Cherenkov luminescence. The PDPC detector is a matrix of avalanche photodiodes, which were read one at a time in a dark count map (DCM) measurement mode (much like a CCD). This reduces the device active area but allows the information from a single avalanche photodiode to be preserved, which is not possible with analog SiPMs. An algorithm to reject the noisiest photodiodes and to correct the measured count rate for the dark current was developed. The results show that, in DCM mode and at (10–13) °C, the PDPC has a dynamic response to different levels of Cherenkov luminescence emitted by a β source and transmitted through an opaque medium. This suggests the potential for this approach to provide quantitative activity measurements. Interestingly, the potential use of the PDPC in DCM mode for direct imaging of Cherenkov luminescence, as a opposed to a scalar measurement device, was also apparent. We showed that a PDPC tile in DCM mode is able to detect and image a β source through its Cherenkov radiation emission. The detector’s dynamic response to different levels of radiation suggests its potential quantitative capabilities, and the DCM mode allows imaging with a better spatial resolution than the conventional event-triggered mode. Finally, the same acquisition procedure and data processing could

  12. Luminescence spectroscopy of Rb2KTiOF5 oxyfluoride single crystals

    Science.gov (United States)

    Kozlov, A. V.; Pustovarov, V. A.; Sarychev, M. N.; Isaenko, L. I.

    2017-09-01

    Spectra of photoluminescence (PL) and X-ray excited luminescence (XRL) in region of 1.5-5.5 eV, PL excitation spectra using synchrotron radiation (3.7-22 eV), time-resolved impulse cathode-luminescence (ICL) spectra, the temperature depending of the XRL, decay kinetics as well as thermoluminescence curves were measured for single crystals Rb2KTiOF5, a promising nonlinear optical material. Single crystals are transparent in microwave, visible and near UV range, inter-band transition energy is Eg = 4.2 eV. Crystalline structure has two disordered mixed position O/F, phase transition in the region of 215 K. All the obtained results indicate that in luminescence spectra nonelementary band 2.2 eV is connected to the emission of self-trapped excitons. Nonelementary band 2.2 eV associated with the presence local distortion in the octahedron TiOF5. It is observed that at interband excitation in VUV region at energies more than 3.5 Eg the effect of multiplication of electronic excitations appears. That determines the high output of XRL and ICL. Luminescence methods of quality control of grown crystals are proposed.

  13. Can glacial shearing of sediment reset the signal used for luminescence dating?

    Science.gov (United States)

    Bateman, Mark D.; Swift, Darrel A.; Piotrowski, Jan A.; Rhodes, Edward J.; Damsgaard, Anders

    2018-04-01

    Understanding the geomorphology left by waxing and waning of former glaciers and ice sheets during the late Quaternary has been the focus of much research. This has been hampered by the difficulty in dating such features. Luminescence has the potential to be applied to glacial sediments but requires signal resetting prior to burial in order to provide accurate ages. This paper explores the possibility that, rather than relying on light to reset the luminescence signal, glacial processes underneath ice might cause resetting. Experiments were conducted on a ring-shear machine set up to replicate subglacial conditions and simulate the shearing that can occur within subglacial sediments. Luminescence measurement at the single grain level indicates that a number (albeit small) of zero-dosed grains were produced and that these increased in abundance with distance travelled within the shearing zone. Observed changes in grain shape characteristics with increasing shear distance indicate the presence of localised high pressure grain-to-grain stresses caused by grain bridges. This appears to explain why some grains became zeroed whilst others retained their palaeodose. Based on the observed experimental trend, it is thought that localised grain stress is a viable luminescence resetting mechanism. As such relatively short shearing distances might be sufficient to reset a small proportion of the luminescence signal within subglacial sediments. Dating of previously avoided subglacial sediments may therefore be possible.

  14. Dependence on liquid temperature and purity of light emission characteristics in single cavitation bubble luminescence

    Energy Technology Data Exchange (ETDEWEB)

    Barbaglia, Mario O; Bonetto, Fabian J [Consejo Nacional de Investigaciones Cientificas y Tecnicas and Instituto Balseiro, Centro Atomico Bariloche, Av. Bustillo 9500, CP8400, Rio Negro (Argentina); Consejo Nacional de Investigaciones Cientificas y Tecnicas, Instituto Balseiro, and Comision Nacional de Energia Atomica, Laboratorio de Cavitacion y Biotecnologia, Centro Atomico Bariloche, Av. Bustillo 9500, CP8400, Rio Negro (Argentina)

    2004-02-15

    We produced single bubbles in water using a visible pulsed laser and studied the characteristics of the light emitted during the bubble collapse time as a function of the water temperature for different water purity values. The water temperature ranged from freezing point (0 deg. C) to near boiling. We measured the luminescence pulse for the mentioned temperature range at various purity values. We also obtained the average bubble lifetime and the average luminescence pulse emitted as a function of water temperature. The main conclusion was that the luminescence can be modified by the water quality and by the water temperature. Maximum luminescence was obtained near the water freezing point.

  15. Dependence on liquid temperature and purity of light emission characteristics in single cavitation bubble luminescence

    International Nuclear Information System (INIS)

    Barbaglia, Mario O.; Bonetto, Fabian J.

    2004-01-01

    We produced single bubbles in water using a visible pulsed laser and studied the characteristics of the light emitted during the bubble collapse time as a function of the water temperature for different water purity values. The water temperature ranged from freezing point (0 deg. C) to near boiling. We measured the luminescence pulse for the mentioned temperature range at various purity values. We also obtained the average bubble lifetime and the average luminescence pulse emitted as a function of water temperature. The main conclusion was that the luminescence can be modified by the water quality and by the water temperature. Maximum luminescence was obtained near the water freezing point

  16. Luminescent materials based on Tb, Eu-containing layered double hydroxides

    International Nuclear Information System (INIS)

    Zhuravleva, N.G.; Eliseev, A.A.; Lukashin, A.V.; Kinast, U.; Tret'yakov, Yu.D.

    2004-01-01

    Luminescent materials on the basis of magnesium-aluminium layered double hydroxides with intercalated anionic complexes of terbium and europium picolinates were synthesized. Relying on data of spectroscopy, elementary and X-ray phase analyses, the change in the rare earth complex structure and metal/ligand ratio, depending on the hydroxide layer charge, determined by Mg/Al ratio in the double hydroxide, were ascertained. The values of quantum yields of luminescence for terbium-containing samples amounted to 30-50% [ru

  17. Synthesis, crystal structure, theoretical study and luminescence ...

    Indian Academy of Sciences (India)

    and Material Engineering, Jiangnan University, Wuxi 214122, P. R. China. cChina-Australia Joint ... School of Chemistry and Chemical Engineering, Nanjing University, Nanjing, 210093, P. R. China e-mail: ..... The title complex is luminescent.

  18. Piezoelectric and deformation potential effects of strain-dependent luminescence in semiconductor quantum well structures

    DEFF Research Database (Denmark)

    Zhang, Aihua; Peng, Mingzeng; Willatzen, Morten

    2017-01-01

    The mechanism of strain-dependent luminescence is important for the rational design of pressure-sensing devices. The interband momentum-matrix element is the key quantity for understanding luminescent phenomena. We analytically solved an infinite quantum well (IQW) model with strain, in the frame......The mechanism of strain-dependent luminescence is important for the rational design of pressure-sensing devices. The interband momentum-matrix element is the key quantity for understanding luminescent phenomena. We analytically solved an infinite quantum well (IQW) model with strain......, in the framework of the 6 × 6 k·p Hamiltonian for the valence states, to directly assess the interplay between the spin-orbit coupling and the strain-induced deformation potential for the interband momentum-matrix element. We numerically addressed problems of both the infinite and IQWs with piezoelectric fields...... to elucidate the effects of the piezoelectric potential and the deformation potential on the strain-dependent luminescence. The experimentally measured photoluminescence variatio½n as a function of pressure can be qualitatively explained by the theoretical results....

  19. Endoscopic Cerenkov luminescence imaging: in vivo small animal tumor model validation

    Science.gov (United States)

    Song, Tianming; Bao, Chengpeng; Hu, Zhenhua; Wang, Kun; Liu, Xia; Tian, Jie

    2015-03-01

    Background: Cerenkov luminescence imaging (CLI) provides a great potential for clinical translation of optical molecular imaging techniques through using clinical approved radiotracers. However, it is difficult to obtain the Cerenkov luminescence signal of deeper biological tissues due to the small magnitude of the signal. To efficiently acquire the weak Cerenkov luminescence, we developed an endoscopic Cerenkov luminescence imaging (ECLI) system to reduce the in vivo imaging depth with minimum invasion, and validated the system on small animal tumor models. Methods: For the ECLI system, the laparoscope was connected to a high sensitive charge-couple device (CCD) camera (DU888+, Andor, UK) by a custom made adapter. We conducted a series of in vitro and in vivo experiments by use of the system. In the in vitro experiment, the endoscopic luminescence images of the 18F-FDG with various activities in EP tubes were acquired using ECLI system, and the sensitivity was compared with conventional CLI system. In the in vivo tumor experiment, 18F-FDG with the activity of 200μCi were intravenously injected into 3 tumor mice. Then the ECLI system was used to acquire the optical images for both non-invasive and invasive conditions. Conclusion: Experimental data showed the ECLI system could detect the 18F-FDG with the activity as low as 1μCi. Furthermore, our preliminary results indicated the possibility of ECLI technique for detecting Cerenkov signals inside the tumor tissue with deeper depth and guiding the surgical operation of tumor excision. We believe that this technique can help to accelerate the clinical translation of CLI.

  20. Luminescence and scintillation of Eu.sup.2+./sup.-doped high silica glass

    Czech Academy of Sciences Publication Activity Database

    Chewpraditkul, W.; Chen, D.; Yu, B.; Zhang, Q.; Shen, Y.; Nikl, Martin; Kučerková, Romana; Beitlerová, Alena; Wanarak, C.; Phunpueok, A.

    2011-01-01

    Roč. 5, č. 1 (2011), s. 40-42 ISSN 1862-6254 R&D Projects: GA MŠk(CZ) ME10084 Institutional research plan: CEZ:AV0Z10100521 Keywords : glasses * Eu 2+ * luminescence * scintillation * time-resolved luminescence * porous materials Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 2.218, year: 2011

  1. Preparation and luminescent properties of ZnO:Ga(La)/polymer nanocomposite

    Czech Academy of Sciences Publication Activity Database

    Gbur, T.; Vlk, M.; Čuba, V.; Beitlerová, Alena; Nikl, Martin

    2013-01-01

    Roč. 56, SEP (2013), s. 102-106 ISSN 1350-4487. [International Conference on Luminescent Detectors and Transformers of Ionizing Radiation 2012 /8./, LUMDETR 2012. Halle (Saale), 10.09.2012-14.09.2012] R&D Projects: GA AV ČR KAN300100802 Institutional support: RVO:68378271 Keywords : zinc oxide * doping * nanocomposite * luminescent materials * photopolymerization Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 1.140, year: 2013

  2. Luminescence enhancement of ZnO-poly(methylmethacrylate) nanocomposite films by incorporation of crystalline BaTiO_3 nanoparticles

    International Nuclear Information System (INIS)

    Kanamori, Tsuyoshi; Han, Yu; Nagao, Daisuke; Kamezawa, Nao; Ishii, Haruyuki; Konno, Mikio

    2016-01-01

    Highlights: • Dielectric barium titanate (BT) nanoparticles incorporated into luminescence films. • Luminescence intensities increased by the BT nanoparticle incorporation. • Incorporation of highly dielectric nanoparticles effective for luminescence enhancement. - Abstract: Incorporation of highly dielectric nanoparticles into luminescent ZnO-polymethylmethacrylate (PMMA) nanocomposite films was undertaken to examine the effect of nanoparticle incorporation on luminescence intensity of the nanocomposite films. ZnO nanoparticles were prepared as inorganic phosphors by a precipitation method. The ZnO nanoparticles were then surface-modified with 3-methacryloxypropyltrimethoxysilane (MPTMS) to be used for fabrication of the ZnO-PMMA nanocomposite film. Barium titanate (BT) nanoparticles were synthesized with a sol-gel method as the highly dielectric nanoparticles, which were also surface-modified with the MPTMS for the incorporation into the nanocomposite films. Luminescence intensity of the nanocomposite films was successfully increased by the nanoparticle incorporation up to a BT content around 15 vol%. The luminescence intensity higher than that measured for the nanocomposite films incorporating SiO_2 nanoparticles indicated that the incorporation of highly dielectric nanoparticles was an effective approach to enhance the luminescence of ZnO nanoparticles in the polymer thin films.

  3. New polymers containing BF{sub 2}-benzoylacetonate groups. Synthesis, luminescence, excimer and exciplex formation

    Energy Technology Data Exchange (ETDEWEB)

    Fedorenko, Elena V., E-mail: gev@ich.dvo.ru [Institute of Chemistry, Far Eastern Branch of the Russian Academy of Sciences, 159, Prosp. 100 letiya Vladivostoka, Vladivostok 690022 (Russian Federation); Mirochnik, Anatolii G.; Beloliptsev, Anton Yu. [Institute of Chemistry, Far Eastern Branch of the Russian Academy of Sciences, 159, Prosp. 100 letiya Vladivostoka, Vladivostok 690022 (Russian Federation)

    2017-05-15

    In the present study, a new synthetic method for the functionalization of polystyrene (PS) and (styrene-methyl methacrylate) copolymer has been developed. Using the new method, polymers containing BF{sub 2}-benzoylacetonate groups have been obtained through double acylation by acetic anhydride with boron trifluoride. Luminescence of the produced polymers in solutions and films has been studied. Quantum yields of polymer solution luminescence are significantly higher than those of the low-molecular-weight analog – boron difluoride benzoylacetonate. For the polymer, in which styrene fragments are separated by methyl methacrylate groups, at low concentrations of the polymer in solution one observes the monomer luminescence of BF{sub 2}-benzoylacetonate groups, while at high concentrations – the excimer luminescence. In case of PS-based polymers, in which BF{sub 2}-benzoylacetonate groups and phenyl rings are not separated, in diluted solutions one observes the fluorescence of the intramolecular exciplexes, while at the concentration increase – the luminescence of intermolecular exciplexes. The ability of excimer formation is responsible for the increased photostability of the produced polymers. - Highlights: •Polymers containing BF{sub 2}-benzoylacetonate groups have been synthesized. •Luminescence of the produced polymers in solutions and films has been studied. •Formation of excimers and exciplexes in solution has been revealed. •Formation of excimers in films increases their photostability.

  4. Co-precipitation synthesis and upconversion luminescence ...

    Indian Academy of Sciences (India)

    Introduction. Researches of rare-earth-doped upconversion (UC) materials as fluorescent labels, temperature-sensing probes, solid-state lasers and new generation television screens have recently started to be considered1,2 due to their enhanced luminescent properties induced by the small size. UC process is the gener-.

  5. Design, synthesis and characterization of a highly luminescent Eu-complex monomer featuring thenoyltrifluoroacetone and 5-acryloxyethoxymethyl-8-hydroxyquinoline

    Energy Technology Data Exchange (ETDEWEB)

    Xu Cunjin [State Key Laboratory of Chemical Engineering, Department of Chemical and Biochemical Engineering, Zhejiang University, Hangzhou 310027 (China); College of Material, Chemistry and Chemical Engineering, Hangzhou Normal University, Hangzhou 310036 (China); Li Bogeng, E-mail: bgli@zju.edu.cn [State Key Laboratory of Chemical Engineering, Department of Chemical and Biochemical Engineering, Zhejiang University, Hangzhou 310027 (China); Wan Jintao; Bu Zhiyang [State Key Laboratory of Chemical Engineering, Department of Chemical and Biochemical Engineering, Zhejiang University, Hangzhou 310027 (China)

    2011-08-15

    A multi-functional ligand, 5-acryloxyethoxymethyl-8-hydroxyquinoline (Hamq), was synthesized, which contained a polymerizable C=C double bond for the copolymerization with other vinyl monomers and acted as photon antenna able to transfer energy to Eu{sup 3+} ions effectively. The triplet state energy of Hamq was determined to be 22,370 cm{sup -1} via the phosphorescence spectra of Hamq and its gadolinium complex. The title complex monomer Eu(tta){sub 2}(amq) was prepared by coordination reaction of Hamq with europium isopropoxide and 2-thenoyltrifluoroacetone (Htta) in dry organic solvents under argon atmosphere and characterized by elemental analysis and IR spectrum. The photophysical properties of the complex were studied in detail with UV-vis, luminescence spectra, luminescence lifetime and quantum yield. The complex exhibited nearly monochromatic red emission at 612 nm, a remarkable luminescence quantum yield at room temperature (30.6%) upon ligand excitation and a long {sup 5}D{sub 0} lifetime (389 {mu}s), which indicated that the ligand Hamq could sensitize the luminescence of Eu(III) ion efficiently in Eu(tta){sub 2}(amq), resulting in a strong luminescence of its copolymer poly[MMA-co-Eu(TTA){sub 2}(amq)] under UV excitation. The excellent luminescence properties of the complex made it not only a promising light-conversion molecular device but also an excellent luminescent monomer. - Highlights: >iWe designed and synthesized a highly luminescent Eu-complex monomer. > Quantum yield and lifetime of the complex are 30.6% and 389 {mu}s, respectively. > Excellent luminescence of the complex made it an excellent luminescent monomer.

  6. Luminescence (IRSL) dating of Yeni Rabat church in Artvin, Turkey

    International Nuclear Information System (INIS)

    Şahiner, Eren; Meriç, Niyazi; Uygun, Selda

    2013-01-01

    Luminescence dating is a chronological method that has been used extensively in terrestrial materials. In this study, we present Infrared Stimulated Luminescence (IRSL) dating results obtained for sediment and pottery samples taken from Yeni Rabat Church, Ardanuç, Artvin, Turkey. For this purpose, equivalent dose (ED) and annual dose rate (AD) of samples were measured. For annual dose rate, concentrations of radioactive isotopes (U, Th, K) were determined by using a high-purity germanium detector. For the equivalent dose, polymineral fine grain SAR (Single Aliquot Regenerative Dose) and MAAD (Multiple Aliquot Additive Dose) procedures were used. The optimal preheat temperature was determined for sediment and pottery samples. Ages were calculated by Aitken's luminescence age calculation method, which found 710±190 years for the pottery sample and 1450±370 years, 1390±420 years, 1430±310 years, 2210±520 years and 1640±390 years for different sediment samples, respectively. These estimated age ranges support the theory that Yeni Rabat Church could have been constructed in medieval times. - Highlights: ► The luminescence (IRSL) ages of the samples, taken from in Yeni Rabat church in Artvin-Turkey were found. ► Equivalent doses and annual doses were determined. ► Polymineral fine grain SAR (Single Aliquot Regenerative Dose) and MAAD (Multiple Aliquot Additive Dose) procedures were used

  7. Toxicity Evaluation of Pig Slurry Using Luminescent Bacteria and Zebrafish

    Directory of Open Access Journals (Sweden)

    Wenyan Chen

    2014-07-01

    Full Text Available Biogas slurry has become a serious pollution problem and anaerobic digestion is widely applied to pig manure treatment for environmental protection and energy recovery. To evaluate environmental risk of the emission of biogas slurry, luminescent bacteria (Vibrio fischeri, larvae and embryos of zebrafish (Danio rerio were used to detect the acute and development toxicity of digested and post-treated slurry. Then the ability of treatment process was evaluated. The results showed that digested slurry displayed strong toxicity to both zebrafish and luminescent bacteria, while the EC50 for luminescent bacteria and the LC50 for larvae were only 6.81% (v/v and 1.95% (v/v respectively, and embryonic development was inhibited at just 1% (v/v. Slurry still maintained a high level of toxicity although it had been treated by membrane bioreactor (MBR, while the LC50 of larvae was 75.23% (v/v and there was a little effect on the development of embryos and V. fischeri; the results also revealed that the zebrafish larvae are more sensitive than embryos and luminescent bacteria to pig slurry. Finally, we also found the toxicity removal rate was higher than 90% after the treatment of MBR according to toxicity tests. In conclusion, further treatment should be used in pig slurry disposal or reused of final effluent.

  8. Efficient green luminescence of terbium oxalate crystals: A case study with Judd-Ofelt theory and single crystal structure analysis and the effect of dehydration on luminescence

    Science.gov (United States)

    Alexander, Dinu; Joy, Monu; Thomas, Kukku; Sisira, S.; Biju, P. R.; Unnikrishnan, N. V.; Sudarsanakumar, C.; Ittyachen, M. A.; Joseph, Cyriac

    2018-06-01

    Design and synthesis of Lanthanide based metal organic framework is a frontier area of research owing to their structural diversity enabling specific applications. The luminescence properties of rare earths, tuned by the structural features of Ln-MOFs are investigated extensively. Rare earth oxalates which can be synthesized in a facile method, ensuring the structural features of MOFs with excellent photoluminescence characteristics deserves much attention. This work is the first time report on the single crystal structure and Judd-Ofelt (JO) theoretical analysis - their correlation with the intense and sharp green luminescence of Terbium oxalate crystals. The intense green luminescence observed for Terbium oxalate crystals for a wide range of excitation from DUV to visible region despite the luminescence limiting factors are discussed. The absence of concentration quenching and lifting up of forbidden nature of f-f transitions, allowing direct excitation of Terbium ions is analysed with the help of JO theory and single crystal structure analysis. The JO analysis predicted the asymmetry of Terbium sites, allowing the electric dipole transitions and from the JO intensity parameters, promising spectroscopic parameters - emission cross section, branching ratio, gain band width and gain coefficient of the material were calculated. The single crystal structure analysis revealed the asymmetry of Tb sites and structure of Terbium oxalate is formed by the hydrogen bonded stacking of overlapped six Terbium membered rings connected by the oxalate ligands. The molecularly thick layers thus formed on the crystal surface are imaged by the atomic force microscopy. The presence of water channels in the structure and the effect of lattice water molecules on the luminescence intensity are also investigated.

  9. Luminescence optically stimulated: theory and applications

    International Nuclear Information System (INIS)

    Rivera M, T.; Azorin N, J.

    2002-01-01

    The thermally stimulated luminescence (Tl) has occupied an important place in the Solid state physics (FES) by the flexibility of the phenomena, mainly for its applications in the fields of Radiation Physics (FR) and Medical Physics (MF). The reason of this phenomena lies in the fact of the electrons release by the action of heat. Under that same reason, it can be used the action of another stimulant agent for releasing the trapped electrons in the metastable states (EM), this agent is the light which has the same effect that the heat, giving as result the production of light photons at using light in the visible spectra, of different wavelength that the excitation light. This phenomena is called Luminescence optically stimulated (LOE). The LOE has a great impact in the Solid State Physics (FES), dating and now in the use of the phenomena as a dosimetric method, alternate to the Tl, for its use in the ionizing and non-ionizing radiations fields. (Author)

  10. Near-surface layer radiation color centers in lithium fluoride nanocrystals: Luminescence and composition

    Energy Technology Data Exchange (ETDEWEB)

    Voitovich, A.P., E-mail: voitovich@imaph.bas-net.by; Kalinov, V.S.; Stupak, A.P.; Novikov, A.N.; Runets, L.P.

    2015-01-15

    Lithium fluoride nanocrystals are irradiated by gamma quanta at 77 K. The radiation color centers formed in a near-surface layer of nanocrystals are studied. Absorption, luminescence and luminescence excitation spectra of the surface defects have been measured. It has been found that the luminescence excitation spectra for aggregated surface centers consist of two or three bands with not very much different intensities. Reactions of the surface centers separately with electrons and with anion vacancies have been investigated. Numbers of anion vacancies and electrons entering into the centers composition have been established and it has been found that F{sub S1}, F{sub S1}{sup −}, F{sub S2}, F{sub S2}{sup −}, F{sub S3}{sup +} and F{sub S3} types of the surface centers are formed. The degree of luminescence polarization has been defined and it has been determined that the polarization degree for F{sub S2}{sup +} centers changes sign under transition from one excitation band to another. It has been shown that during irradiation at 77 K radiation-induced defects are formed more efficiently on the surface than in the bulk. - Highlights: • Radiative color centers were fabricated in lithium fluoride nanocrystals. • The unique absorption and luminescence characteristics are inherent in the centers. • The reactions of these centers with electrons and anion vacancies were studied. • The degree of luminescence polarization was defined. • Numbers of anion vacancies and electrons forming the centers were established.

  11. Spectral study of the luminescence produced by the excitation of noble gases by alpha-rays; Etude spectrale de la luminescence due a l'excitation des gaz rares par les rayons alpha

    Energy Technology Data Exchange (ETDEWEB)

    Koch, L [Commissariat a l' Energie Atomique, Saclay (France).Centre d' Etudes Nucleaires

    1960-07-01

    Luminescence spectra of the noble gases He, A, Kr and Xe are studied under excitation by {alpha} rays. It is shown that the energy is transferred from excited levels of these gases to Hg and N{sub 2} impurities for impurity concentrations respectively less than 10{sup 6} and 10{sup 4}. These results confirm previous measurements concerning the period of luminescence and its variations versus nitrogen concentration in noble gases. (author) [French] On etudie les spectres de luminescence des gaz rares, He, A, Kr et Xe excites par une source intense de rayons {alpha}. Le transfert d'energie des etats excites des gaz rares sur les impuretes mercure et azote pour des concentrations respectives de ces impuretes inferieures a 1 ppm et 100 ppm est demontre. Ces resultats confirment les mesures anterieures concernant la duree de luminescence et ses variations avec la concentration d'azote dans les gaz rares. (auteur)

  12. Recent advances in thermoluminescence and photostimulated luminescence detection methods for irradiated foods

    International Nuclear Information System (INIS)

    Sanderson, D.C.W.; Carmichael, L.A.; Naylor, J.D.

    1996-01-01

    Thermoluminescence (TL) and photostimulated luminescence (PSL) are radiation-specific phenomena resulting from energy storage by trapped charge carriers in dielectric materials following irradiation. Releasing such stored energy by thermal or optical stimulation can result in detectable luminescence emission during the relaxation processes which follow. These approaches can be applied to inorganic components present either as inherent parts of foods or as adhering contaminants, and to bio-inorganic systems. The strengths of these techniques lies in their radiation-specificity, and the wide range of sample types which may by analysed. The Scottish Universities Research and Reactor Centre (SURRC) has been involved in the development and application of luminescence methods since 1986, during which time over 4000 analyses of more than 800 different food samples have been performed for research purposes, or in support of UK food labelling regulations. This paper discusses the present scope of luminescence techniques, and identifies areas where recent work has extended the range of applications, and indicates areas where further investigations may be worthwhile. (author)

  13. Thermal and electron stimulated luminescence of natural bones, commercial hydroxyapatite and collagen.

    Science.gov (United States)

    Roman-Lopez, J; Correcher, V; Garcia-Guinea, J; Rivera, T; Lozano, I B

    2014-01-01

    The luminescence (cathodoluminescence and thermoluminescence) properties of natural bones (Siberian mammoth and adult elephant), commercial hydroxyapatite and collagen were analyzed. Chemical analyses of the natural bones were determined using by Electron Probe Micro-Analysis (EMPA). Structural, molecular and thermal characteristics were determined by X-ray Diffraction (XRD), Raman spectroscopy and Differential Thermal and Thermogravimetric analysis (DTA-TG). Cathodoluminescence (CL) spectra of natural bones and collagen showed similar intense broad bands at 440 and 490 nm related to luminescence of the tetrahedral anion [Formula: see text] or structural defects. A weaker luminescence exhibited at 310 nm could be attributed to small amount of rare earth elements (REEs). Four luminescent bands at 378, 424, 468 and 576 nm were observed in the commercial hydroxyapatite (HAP). Both natural bones and collagen samples exhibited natural thermoluminescence (NTL) with well-defined glow curves whereas that the induced thermoluminescence (ITL) only appears in the samples of commercial hydroxyapatite and collagen. Additional explanations for the TL anomalous fading of apatite, as a crucial difficulty performing dosimetry and dating, are also considered. Copyright © 2013 Elsevier B.V. All rights reserved.

  14. The exploration and characterization of an orange emitting long persistent luminescence phosphor LiSr4(BO3)3:Eu2+

    International Nuclear Information System (INIS)

    Jin, Yahong; Hu, Yihua; Wu, Haoyi; Chen, Li; Wang, Xiaojuan

    2016-01-01

    An orange emitting long persistent phosphor LiSr 4 (BO 3 ) 3 :Eu 2+ was prepared successfully using a conventional solid state reaction method. The luminescent and persistent luminescence properties were studied using fluorescence spectra, decay curves, persistent luminescence spectra and thermoluminescence (TL) glow curves. The effects on the fluorescence and persistent luminescence properties by the dosage of Li 2 CO 3 were explored. The relationship between the Eu 2+ contents and persistent luminescence properties were studied. The optimal doping concentration of Eu 2+ was experimentally to be 1 mol%. The detailed processes and a possible mechanism were also discussed. - Highlights: • Li 2 CO 3 plays a critical role in producing persistent luminescence. • 40 % excess of Li 2 CO 3 makes the largest enhancement on persistent luminescence. • The optimal doping concentration of Eu 2+ was experimentally to be 1mol %. • Possible mechanism for persistent luminescence was discussed.

  15. Microwave assisted synthesis of luminescent carbonaceous nanoparticles from silk fibroin for bioimaging.

    Science.gov (United States)

    Gao, Hongzhi; Teng, Choon Peng; Huang, Donghong; Xu, Wanqing; Zheng, Chaohui; Chen, Yisong; Liu, Minghuan; Yang, Da-Peng; Lin, Ming; Li, Zibiao; Ye, Enyi

    2017-11-01

    Bombyx mori silk as a natural protein based biopolymer with high nitrogen content, is abundant and sustainable because of its mass product all over the world per year. In this study, we developed a facile and fast microwave-assisted synthesis of luminescent carbonaceous nanoparticles using Bombyx mori silk fibroin and silk solution as the precursors. As a result, the obtained carbonaceous nanoparticles exhibit a photoluminescence quantum yield of ~20%, high stability, low cytotoxicity, high biocompatibility. Most importantly, we successfully demonstrated bioimaging using these luminescent carbonaceous nanoparticles with excitation dependent luminescence. In addition, the microwave-assisted hydrothermal method can be extended to convert other biomass into functional nanomaterials. Copyright © 2017 Elsevier B.V. All rights reserved.

  16. Recombination luminescence in irradiated silicon - Effects of thermal annealing and lithium impurity.

    Science.gov (United States)

    Johnson, E. S.; Compton, W. D.

    1971-01-01

    Use of luminescence in irradiated silicon to determine the thermal stability of the defects responsible for the recombination. It is found that the defect responsible for the zero-phonon line at 0.97 eV has an annealing behavior similar to that of the divacancy and that the zero-phonon line at 0.79 eV anneals in a manner similar to the G-15 or K-center. Annealing at temperatures up to 500 C generates other defects whose luminescence is distinct from that seen previously. Addition of lithium to the material produces defects with new characteristic luminescence. Of particular importance is a defect with a level at E sub g -1.045 eV.

  17. Luminescent properties of terbium complexes with catecholamines and their application in analysis

    International Nuclear Information System (INIS)

    Kravchenko, T.B.; Bel'tyukova, S.V.; Kononenko, L.I.; Poluehktov, N.S.

    1982-01-01

    Tb complexing with a representative of catecholamines - adrenaline - is studied using the luminescence method. It is found, that the complexing takes place in alkaline medium (pH 12.0). To prevent from compound oxidation with air oxygen and to create the necessary pH in solution sodium borohydride is used. The highest luminescence intensity is achieved when the reaction occurs in aqueous-isopropanol solutions. It is established that in the complexes formed the ratio of components is the following: Tb:adrenaline=1:3. Luminescent properties of Tb complex with adrenaline are used to determine the latter. The least detectable amount of adrenaline constitutes 0.02 μg, the determination error does not exceed 5.5% [ru

  18. Highly visible-light luminescence properties of the carboxyl-functionalized short and ultrashort MWNTs

    International Nuclear Information System (INIS)

    Luo Yongsong; Xia Xiaohong; Liang Ying; Zhang Yonggang; Ren Qinfeng; Li Jialin; Jia Zhijie; Tang Yiwen

    2007-01-01

    Luminescence of the short multiwalled carbon nanotubes (MWNTs) conjugated with carboxylic acid groups has been studied. The results show that the carboxyl-functionalized short MWNTs could emit luminescence and the emission peak appears at 500 nm with a corresponding optimal excitation wavelength centering at 310 nm. When the short MWNTs are filtered through 0.15 μm polytetrafluoroethylene (PTFE) membrane, the ultrashort MWNTs are obtained from the filtrate. An interesting feature for the ultrashort MWNTs is that the emission intensity is strengthened and the peak is slightly blue shifted to 460 nm. This result indicates that the luminescence properties of MWNTs are strongly affected by the tube length. After chemical oxidization cutting, defects and carboxylic acid groups at the tube end and/or sidewall can be produced; the more shorten of MWNTs, the better dispersion and carboxylic passivation of the nanotubes, and the more intense luminescence emissions. The broad emissions are logically attributed to the trapping of excitation energy by defect sites in the carboxyl-functionalized nanotube structure. - Graphical abstract: Luminescence of the short and ultrashort multiwalled carbon nanotubes (MWNTs) conjugated with carboxylic acid groups, which is logically attributed to the trapping of excitation energy by defect sites, has been studied

  19. Acquisition of a bodily-tactile language as first language

    DEFF Research Database (Denmark)

    Ask Larsen, Flemming

    2013-01-01

    Language acquisition in the bodily-tactile modality is difficult to understand, describe, and support. This chapter advocates a reinterpretation of the gestural and idiosyncratic bodily-tactile communication of people with congenital deafblindness (CDB) in terms of early language acquisition...... towards Tactile Sign Language (TSL). The access to participation in complex TSL culture is crucial for language acquisition. We already know how to transfer the patterns of social interaction into the bodily-tactile modality. This is the fundation on which to build actual linguistic participation. TSL...... as a first language is presently a theoretic possibility. We need more research on how to accommodate TSL to language Development and on how to fit TSL into participation in complex cultural activities....

  20. The extended Beer-Lambert theory for ray tracing modeling of LED chip-scaled packaging application with multiple luminescence materials

    Science.gov (United States)

    Yuan, Cadmus C. A.

    2015-12-01

    Optical ray tracing modeling applied Beer-Lambert method in the single luminescence material system to model the white light pattern from blue LED light source. This paper extends such algorithm to a mixed multiple luminescence material system by introducing the equivalent excitation and emission spectrum of individual luminescence materials. The quantum efficiency numbers of individual material and self-absorption of the multiple luminescence material system are considered as well. By this combination, researchers are able to model the luminescence characteristics of LED chip-scaled packaging (CSP), which provides simple process steps and the freedom of the luminescence material geometrical dimension. The method will be first validated by the experimental results. Afterward, a further parametric investigation has been then conducted.

  1. Concentration depolarization of luminescence of Eu3+-doped glasses

    International Nuclear Information System (INIS)

    Bodunov, E.N.; Lebedev, V.P.; Malyshev, V.A.; Przheuskij, A.K.

    1989-01-01

    Experimental study of concentrational depolarization luminescence (CDL) of phosphate and germanate glasses, containing Eu 3+ ions, has been carried out. On the basis of three-body self-consistent approximation the theory of CDL is conceived, which takes into account Eu-Eu interaction of higher multipolarities. By comparing the theory with the experiment energy transfer radii for Eu-Eu dipole-dipole, dipole-quadrupole and quadrupole-quadrupole interactions are determined. The attempt to discriminate Eu-Eu interaction types in the studied range of Eu 3+ ion concentration change has failed owing to law accuracy of luminescence emittance anisotropy measurement

  2. Organic scintillators with long luminescent lifetimes for radiotherapy dosimetry

    DEFF Research Database (Denmark)

    Beierholm, Anders Ravnsborg; Lindvold, Lars René; Andersen, Claus Erik

    2011-01-01

    of experiments performed using two organic scintillators, one commercially available and one custom made. The luminescent lifetimes of the scintillators have been measured using i) optical excitation by pulsed UV light, and ii) irradiative excitation using high-energy X-rays from a linac. A luminescent lifetime...... component on the order of 20 μs was estimated for the custom-made organic scintillator, while the commercial scintillator exhibited a fast component of approximately 5 ns lifetime (7 ns as stated by the manufacturer) and an approximate 10 μs lifetime slow component. Although these lifetimes are not long...

  3. Stimulation of mineral-specific luminescence from multi-mineral samples

    DEFF Research Database (Denmark)

    Duller, G.A.T.; Bøtter-Jensen, L.; Poolton, N.R.J.

    1995-01-01

    Grains of quartz and potassium-rich feldspar have been mixed in known ratios to produce samples of known mineralogical composition, analogous to those found in natural sedimentary deposits. The variation of the green light stimulated luminescence (GLSL), as a function of sample temperature......, was measured for each of these mixtures in order to attempt to isolate a luminescence signal that originates specifically from just one of the components. As the sample is heated from room temperature to 450 degrees C, thermal quenching reduces the signal from the quartz component to near zero, while that from...... geological samples....

  4. Luminescence as a new detection method for non-relativistic highly ionizing particles in water/ice neutrino telescopes

    Energy Technology Data Exchange (ETDEWEB)

    Pollmann, Anna [Bergische Universitaet Wuppertal (Germany); Collaboration: IceCube-Collaboration

    2016-07-01

    Cosmic ray detectors use air as a radiator for luminescence. In water and ice detectors Cherenkov light is the dominant light producing mechanism when the particle velocity exceeds the Cherenkov threshold, approximately three quarters of the speed of light. Luminescence is produced by highly ionizing particles passing through matter due to the excitation of the surrounding atoms. The observables of luminescence, such as the wavelength spectrum and decay times, are highly dependent on the properties of the medium. Therefore, the results of measurements, in which luminescence was produced by particles passing through water or ice, vary by two orders of magnitude in intensity. It is shown that, even for the most conservative intensity value, luminescence can be used as a detection method for highly ionizing particles with velocities below the Cherenkov threshold. These could be magnetic monopoles or other massive and highly penetrating exotic particles. In the most optimistic case, luminescence contributes even to the light output of standard model particles.

  5. Luminescence of Ce doped oxygen crystalline compounds based on Hf and Ba

    CERN Document Server

    Borisevich, A E; Lecoq, P

    2003-01-01

    The luminescence properties of the Ce-doped hafnium and barium compounds have been investigated to determine their potential as heavy scintillation materials. Compounds have been prepared by solid state synthesis. All of them have shown a bright luminescence attributed to trivalent cerium. Emission bands are peaked in the 425-475nm spectral region at room temperature.

  6. Luminescent lanthanide reporters: new concepts for use in bioanalytical applications

    International Nuclear Information System (INIS)

    Vuojola, Johanna; Soukka, Tero

    2014-01-01

    Lanthanides represent the chemical elements from lanthanum to lutetium. They intrinsically exhibit some very exciting photophysical properties, which can be further enhanced by incorporating the lanthanide ion into organic or inorganic sensitizing structures. A very popular approach is to conjugate the lanthanide ion to an organic chromophore structure forming lanthanide chelates. Another approach, which has quickly gained interest, is to incorporate the lanthanide ions into nanoparticle structures, thus attaining improved specific activity and a large surface area for biomolecule immobilization. Lanthanide-based reporters, when properly shielded from the quenching effects of water, usually express strong luminescence emission, multiple narrow emission lines covering a wide wavelength range, and exceptionally long excited state lifetimes enabling time-gated luminescence detection. Because of these properties, lanthanide-based reporters have found widespread applications in various fields of life. This review focuses on the field of bioanalytical applications. Luminescent lanthanide reporters and assay formats utilizing these reporters pave the way for increasingly sensitive, simple, and easily automated bioanalytical applications. (topical review)

  7. Luminescent sensing of organophosphates using europium(III) containing imprinted polymers prepared by RAFT polymerization

    International Nuclear Information System (INIS)

    Southard, Glen E.; Van Houten, Kelly A.; Ott, Edward W.; Murray, George M.

    2007-01-01

    Molecularly imprinted polymers capable of sensing organophosphorous compounds by luminescence have been prepared by reversible addition fragmentation chain transfer (RAFT) polymerization. The polymer contained a dithiobenzoate substituted tris(β-diketonate) europium(III) complex which served as a polymerization substrate and as a luminescent binding site for pinacolyl methylphosphonate (PMP), the hydrolysis product of the nerve agent Soman. The resultant polymer allowed quantitation of PMP in the low ppb range with minimal interference from similar compounds. Polymers were characterized by luminescence spectroscopy and scanning electron microscopy

  8. Calibration beads containing luminescent lanthanide ion complexes

    Science.gov (United States)

    The reliability of lanthanide luminescence measurements, by both flow cytometry and digital microscopy, will be enhanced by the availability of narrow-band emitting lanthanide calibration beads. These beads can also be used to characterize spectrographic instruments, including mi...

  9. Luminescence dating in archaeology

    International Nuclear Information System (INIS)

    Wintle, A.G.

    2001-01-01

    Thermoluminescence (TL) dating is routinely applied to burnt lithic material. Simple fires are capable of enabling stones weighing a few hundred grams to reach 450 o C, thus zeroing the TL signal. TL dates have been obtained for Upper and Lower Paleolithic sites in Europe and the Near East. TL dating continues to be used for dating pottery and for authentification of ceramic works of art. Some recent studies report the use of optically stimulated luminescence (OSL) (also know as photoluminescence) for dating very small samples of quartz, e.g. from small pieces of pottery or frm metallurgical slag The major recent advance has been in the development of a reliable laboratory procedure for using the OSL signal from quartz to obtain the past radiation exposure. The quartz OSL signal is extremely sensitive to light and is reduced to a negligible level on exposure to direct sunlight for radionuclides during burial, signal to date san.sized quartz grains extracted from sediments, The OSL signal is stimulated by 470 nm light from emitting diodes and the detected using flirters centred on 340 nm A similar signal can be obtained from feldspar grain when are exposed to infrared wavelengths around 880 nm. The infrared stimulated luminescence (IRSL) signals is also rapidly depleted by exposure to sunlight, and dating of colluvial deposits from archaeological sites has been reported

  10. Limestone: some observations on luminescence in the region of 360 nm

    International Nuclear Information System (INIS)

    Galloway, R.B.

    2003-01-01

    An empirical study of luminescence around 360 nm from limestone is presented. Thermoluminescence glow curves from natural limestone show broad peaks at 440 deg. C, 350 deg. C, 530 deg. C and 286 deg. C in order of decreasing amplitude in contrast to the usual observation, for luminescence around 535 nm, of a sharp peak at 286 deg. C with a broader less intense peak at 350 deg. C. Recuperation occurs around 350 deg. C and 525 deg. C, which has a time dependence consistent with quantum tunnelling. Dependent on the history of heating and light exposure of the sample, sharp peaks at about 325 deg. C and 425 deg. C can be observed. Laboratory irradiated limestone shows a peak at 140 deg. C. The stimulation of luminescence by light of 470 nm with preheating at 145 deg. C for 300 s, shows an increasing signal for successive cycles of measurement associated with the heating, light exposure having little influence. Beta irradiation of a sample, with the same measurement conditions, gives a signal which increases in proportion to radiation dose but which does not survive storage for 17 h. Time resolved luminescence spectra, with no preheating, show a luminescence lifetime between stimulation and emission of less than a few μs for natural limestone, and an exponential increase in signal with increase in temperature (over the rang 20-167 deg. C) during stimulation. A signal proportional to laboratory applied beta dose is measurable at room temperature, with lifetime between stimulation and emission of this signal of 35 μs, but it does not survive heating to 100 deg. C

  11. New Nanomaterials and Luminescent Optical Sensors for Detection of Hydrogen Peroxide

    Directory of Open Access Journals (Sweden)

    Natalia A. Burmistrova

    2015-10-01

    Full Text Available Accurate methods that can continuously detect low concentrations of hydrogen peroxide (H2O2 have a huge application potential in biological, pharmaceutical, clinical and environmental analysis. Luminescent probes and nanomaterials are used for fabrication of sensors for H2O2 that can be applied for these purposes. In contrast to previous reviews focusing on the chemical design of molecular probes for H2O2, this mini-review highlights the latest luminescent nanoparticular materials and new luminescent optical sensors for H2O2 in terms of the nanomaterial composition and luminescent receptor used in the sensors. The nanomaterial section is subdivided into schemes based on gold nanoparticles, polymeric nanoparticles with embedded enzymes, probes showing aggregation-induced emission enhancement, quantum dots, lanthanide-based nanoparticles and carbon based nanomaterials, respectively. Moreover, the sensors are ordered according to the type of luminescent receptor used within the sensor membranes. Among them are lanthanide complexes, metal-ligand complexes, oxidic nanoparticles and organic dyes. Further, the optical sensors are confined to those that are capable to monitor the concentration of H2O2 in a sample over time or are reusable. Optical sensors responding to gaseous H2O2 are not covered. All nanomaterials and sensors are characterized with respect to the analytical reaction towards H2O2, limit of detection (LOD, analytical range, electrolyte, pH and response time/incubation time. Applications to real samples are given. Finally, we assess the suitability of the nanomaterials to be used in membrane-based sensors and discuss future trends and perspectives of these sensors in biomedical research.

  12. MetR and CRP bind to the Vibrio harveyi lux promoters and regulate luminescence.

    Science.gov (United States)

    Chatterjee, Jaidip; Miyamoto, Carol M; Zouzoulas, Athina; Lang, B Franz; Skouris, Nicolas; Meighen, Edward A

    2002-10-01

    The induction of luminescence in Vibrio harveyi at the later stages of growth is controlled by a quorum-sensing mechanism in addition to nutritional signals. However, the mechanism of transmission of these signals directly to the lux promoters is unknown and only one regulatory protein, LuxR, has been shown to bind directly to lux promoter DNA. In this report, we have cloned and sequenced two genes, crp and metR, coding for the nutritional regulators, CRP (cAMP receptor protein) and MetR (a LysR homologue), involved in catabolite repression and methionine biosynthesis respectively. The metR gene was cloned based on a general strategy to detect lux DNA-binding proteins expressed from a genomic library, whereas the crp gene was cloned based on its complementation of an Escherichia coli crp mutant. Both CRP and MetR were shown to bind to lux promoter DNA, with CRP being dependent on the presence of cAMP. Expression studies indicated that the two regulators had opposite effects on luminescence: CRP was an activator and MetR a repressor. Disruption of crp decreased luminescence by about 1,000-fold showing that CRP is a major activator of luminescence the same as LuxR, whereas disruption of MetR resulted in activation of luminescence over 10-fold, confirming its function as a repressor. Comparison of the levels of the autoinducers involved in quorum sensing excreted by V. harveyi, and the crp and metR mutants, showed that autoinducer production was not significantly different, thus indicating that the nutritional signals do not affect luminescence by changing the levels of the signals required for quorum sensing. Indeed, the large effects of these nutritional sensors show that luminescence is controlled by multiple signals related to the environment and the cell density which must be integrated at the molecular level to control expression at the lux promoters.

  13. X-ray excited optical luminescence (XEOL) and its application to porous silicon

    International Nuclear Information System (INIS)

    Hill, D.A.

    1998-09-01

    X-ray Excited Optical Luminescence (XEOL) is investigated as a local structural probe of the light-emitting sites in porous silicon. A detailed microscopic model of the XEOL process in porous silicon is proposed. A central aspect of the technique is an assessment of the spatial separation between the primary photoionisation event and subsequent optical radiative recombination. By constructing a Monte Carlo simulation of hot electron propagation in silicon using both elastic and inelastic scattering cross-sections, the mean minimum range of luminescence excitation can be calculated. This range is estimated as 546±1A for the silicon K-edge (∼ 1839eV), but is reduced to 8.9±0.1A for the silicon L 2,3 -edge (∼ 99eV). From known porous silicon properties, it is concluded that this mean minimum range is comparable to the actual range of excitation. Hence, more localised structural information may be obtained from L 2,3 -edge XEOL measurements. This important difference between the two spectra has been neglected in previous studies. Simultaneous measurements of the XEOL and total electron yield (TEY) x-ray absorption spectra (XAS) have been conducted at both the silicon K-edge and L 2,3 -edge for various porous silicon samples and related materials. Measurements have been conducted at the Si K-edge on a rapid thermally oxidised (RTO) porous silicon sample. XEOL spectra yield two distinct luminescence bands in the visible region. From multi-bunch wavelength-selective XEOL measurements, it is concluded that there are blue luminescent defective silica sites together with a red luminescent site originating from silicon-like material. The spectral time decay curve under pulsed x-ray excitation gives two distinct decay components; one fast in the range of a few nanoseconds and the other slow in the range of microseconds. Time-resolved XEOL measurements in single-bunch mode show that the fast band mirrors the blue wavelength XEOL whereas the slow band correlates with the

  14. Luminescence studies on phosphor screens

    International Nuclear Information System (INIS)

    Panayiotakis, G.; Nomikos, C.; Bakas, A.; Proimos, B.

    1994-01-01

    We report our results on x-ray phosphor screens prepared of some new materials focusing attention on their efficiency under fluoroscopy conditions, on optimization conditions and on comparisons among the various materials. All data are presented in absolute values. A theoretical model is presented, that takes into account the granular structure of the screens, permitting the explanation and prediction of the luminescence properties of the screens. (authors)

  15. LUMINESCENCE DETERMINATION OF ETODOLAC

    Directory of Open Access Journals (Sweden)

    A. V. Yegorova

    2015-02-01

    Full Text Available A highly sensitive, simple and rapid method for determination of non-steroidal anti- inflammatory drug – etodolac (Et in washings from surfaces of pharmaceutical equipment have been proposed. The intensity of native luminescence of water-n-propanol solutions of etodolac (λex= 274 nm; λlum= 350 nm was used as the analytical signal. The calibration graph is linear in the concentration range 0.014-2.3 μg/ml, the limit of detection is 0.5 ng/ml.

  16. Experimental and modelling study of pulsed optically stimulated luminescence in quartz, marble and beta irradiated salt

    International Nuclear Information System (INIS)

    Pagonis, V; Mian, S M; Barnold, C; Chithambo, M L; Christensen, E

    2009-01-01

    Optical stimulation luminescence (OSL) signals can be obtained using continuous-wave optical stimulation (CW-OSL), the linear modulation optical stimulation method (LM-OSL) and the time-resolved optical stimulation (TR-OSL) method. During TR-OSL measurements, the stimulation and emission of luminescence are experimentally separated in time by using short light pulses. This paper presents new TR-OSL data for annealed high purity synthetic quartz, for marble and for commercially available iodized salt. A new type of behaviour for TR-OSL signals for quartz and iodized salt is presented, in which the OSL signal exhibits a nonmonotonic behaviour during optical stimulation; this type of behaviour has not been reported previously in the literature for quartz. Furthermore, a luminescence component with very long luminescence lifetime is reported for some quartz aliquots, which may be due to the presence of a delayed-OSL (DOSL) mechanism in quartz. A new kinetic model for TR-OSL in quartz is presented, which is based on a main electron trap and on several luminescence centres. The model is used to quantitatively fit several sets of experimental data of pulsed optically stimulated luminescence from quartz.

  17. Luminescence of Quantum Dots by Coupling with Nonradiative Surface Plasmon Modes in a Scanning Tunneling Microscope

    International Nuclear Information System (INIS)

    Romero, M.J.; van de Lagemaat, J.

    2009-01-01

    The electronic coupling between quantum dots (QDs) and surface plasmons (SPs) is investigated by a luminescence spectroscopy based on scanning tunneling microscopy (STM). We show that tunneling luminescence from the dot is excited by coupling with the nonradiative plasmon mode oscillating at the metallic tunneling gap formed during the STM operation. This approach to the SP excitation reveals aspects of the SP-QD coupling not accessible to the more conventional optical excitation of SPs. In the STM, luminescence from the dot is observed when and only when the SP is in resonance with the fundamental transition of the dot. The tunneling luminescence spectrum also suggests that excited SP-QD hybrid states can participate in the excitation of QD luminescence. Not only the SP excitation regulates the QD luminescence but the presence of the dot at the tunneling gap imposes restrictions to the SP that can be excited in the STM, in which the SP cannot exceed the energy of the fundamental transition of the dot. The superior SP-QD coupling observed in the STM is due to the tunneling gap acting as a tunable plasmonic resonator in which the dot is fully immersed.

  18. Synthesis and luminescence properties of tris(bipyridine)ruthenium(II)-containing vinyl polymers

    International Nuclear Information System (INIS)

    Furue, Masaoki; Sumi, Katsuhiro; Nozakura, Shun-ichi

    1981-01-01

    The luminescence properties of poly[Ru(bpy) 2 (6-vinyl-bpy)-co-6-vinyl-bpy], (I) were compared with those of Ru(bpy) 3 2+ at 77 - 298 K. A larger depletion of luminescence intensity and lifetime was observed in I in fluid solution. The dynamic quenching processes were suggested to be the dominant factor for the energy dissipation in I. (author)

  19. Luminescent determination of trace amounts of terbium using diantipyrylmethane and salicylic acid

    Energy Technology Data Exchange (ETDEWEB)

    Tishchenko, M A; Gerasimenko, G I; Poluehktov, N S [AN Ukrainskoj SSR, Odessa. Inst. Obshchej i Neorganicheskoj Khimii

    1978-01-01

    To elucidate the possibility of using pyrazolone-5-diantipyril-methane (DAM) derivative for determination of terbium microimpurities, the conditions have been studied of luminescent determination of terbium in complex compounds containing an ion of rare-earth element, diantipyrilmethane, and salicylic acid (Sal.). The ratio between the components in the complex REE-DAM-Sal is 1:1:3. La, Y, Gd do not affect the luminescence intensity of terbium complex. A luminescent method of determining terbium traces in highly pure oxides of lanthanum, gadolinium, lutetium, and yttrium has been developed in which suspensions of complex precipitation are used. The amount of terbium determined in oxide of lanthanum, gadolinium, and lutetium is (1-5)x10/sup -6/% and (2-3)x10/sup -5/% in yttrium oxide.

  20. Novel Luminescent Probe Based on a Terbium(III) Complex for Hemoglobin Determination

    Science.gov (United States)

    Yegorova, A. V.; Leonenko, I. I.; Aleksandrova, D. I.; Scrypynets, Yu. V.; Antonovich, V. P.; Ukrainets, I. V.

    2014-09-01

    We have studied the spectral luminescent properties of Tb(III) and Eu(III) complexes with a number of novel derivatives of oxoquinoline-3-carboxylic acid amides (L1-L5 ). We have observed quenching of the luminescence of 1:1 Tb(III)-L1-5 complexes by hemoglobin (Hb), which is explained by resonance energy transfer of electronic excitation from the donor (Tb(III)-L1-5 ) to the acceptor (Hb). Using the novel luminescent probe Tb(III)-L1, we have developed a method for determining Hb in human blood. The calibration Stern-Volmer plot is linear in the Hb concentration range 0.6-36.0 μg/mL, detection limit 0.2 μg/mL (3·10-9 mol/L).

  1. Luminescence enhancement of ZnO-poly(methylmethacrylate) nanocomposite films by incorporation of crystalline BaTiO{sub 3} nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    Kanamori, Tsuyoshi; Han, Yu; Nagao, Daisuke, E-mail: dnagao@tohoku.ac.jp; Kamezawa, Nao; Ishii, Haruyuki; Konno, Mikio

    2016-09-15

    Highlights: • Dielectric barium titanate (BT) nanoparticles incorporated into luminescence films. • Luminescence intensities increased by the BT nanoparticle incorporation. • Incorporation of highly dielectric nanoparticles effective for luminescence enhancement. - Abstract: Incorporation of highly dielectric nanoparticles into luminescent ZnO-polymethylmethacrylate (PMMA) nanocomposite films was undertaken to examine the effect of nanoparticle incorporation on luminescence intensity of the nanocomposite films. ZnO nanoparticles were prepared as inorganic phosphors by a precipitation method. The ZnO nanoparticles were then surface-modified with 3-methacryloxypropyltrimethoxysilane (MPTMS) to be used for fabrication of the ZnO-PMMA nanocomposite film. Barium titanate (BT) nanoparticles were synthesized with a sol-gel method as the highly dielectric nanoparticles, which were also surface-modified with the MPTMS for the incorporation into the nanocomposite films. Luminescence intensity of the nanocomposite films was successfully increased by the nanoparticle incorporation up to a BT content around 15 vol%. The luminescence intensity higher than that measured for the nanocomposite films incorporating SiO{sub 2} nanoparticles indicated that the incorporation of highly dielectric nanoparticles was an effective approach to enhance the luminescence of ZnO nanoparticles in the polymer thin films.

  2. Design of Interrogation Protocols for Radiation Dose Measurements Using Optically-Stimulated Luminescent Dosimeters.

    Science.gov (United States)

    Abraham, Sara A; Kearfott, Kimberlee J; Jawad, Ali H; Boria, Andrew J; Buth, Tobias J; Dawson, Alexander S; Eng, Sheldon C; Frank, Samuel J; Green, Crystal A; Jacobs, Mitchell L; Liu, Kevin; Miklos, Joseph A; Nguyen, Hien; Rafique, Muhammad; Rucinski, Blake D; Smith, Travis; Tan, Yanliang

    2017-03-01

    Optically-stimulated luminescent dosimeters are capable of being interrogated multiple times post-irradiation. Each interrogation removes a fraction of the signal stored within the optically-stimulated luminescent dosimeter. This signal loss must be corrected to avoid systematic errors in estimating the average signal of a series of optically-stimulated luminescent dosimeter interrogations and requires a minimum number of consecutive readings to determine an average signal that is within a desired accuracy of the true signal with a desired statistical confidence. This paper establishes a technical basis for determining the required number of readings for a particular application of these dosimeters when using certain OSL dosimetry systems.

  3. Systematic development of new thermoluminescence and optically stimulated luminescence materials

    Energy Technology Data Exchange (ETDEWEB)

    Yukihara, E.G., E-mail: eduardo.yukihara@okstate.edu [Physics Department, 145 Physical Sciences II, Oklahoma State University, Stillwater, OK 74078 (United States); Milliken, E.D.; Oliveira, L.C. [Physics Department, 145 Physical Sciences II, Oklahoma State University, Stillwater, OK 74078 (United States); Orante-Barron, V.R. [Departamento de Investigacion en Polimeros y Materiales, Universidad de Sonora, Hermosillo, Sonora 83000, Mexico (Mexico); Jacobsohn, L.G. [Center for Optical Materials Science and Engineering Technologies (COMSET), and School of Materials Science and Engineering, Clemson University, Clemson, SC (United States); Blair, M.W. [Materials Science and Technology Division, Los Alamos National Laboratory, Los Alamos, NM 87545 (United States)

    2013-01-15

    This paper presents an overview of a systematic study to develop new thermoluminescence (TL) and optically stimulated luminescence (OSL) materials using solution combustion synthesis (SCS) for applications such as personal OSL dosimetry, 2D dose mapping, and temperature sensing. A discussion on the material requirements for these applications is included. We present X-ray diffraction (XRD) data on single phase materials obtained with SCS, as well as radioluminescence (RL), TL and OSL data of lanthanide-doped materials. The results demonstrate the possibility of producing TL and OSL materials with sensitivity similar to or approaching those of commercial TL and OSL materials used in dosimetry (e.g., LiF:Mg,Ti and Al{sub 2}O{sub 3}:C) using SCS. The results also show that the luminescence properties can be improved by Li co-doping and annealing. The presence of an atypical TL background and anomalous fading are discussed and deserve attention in future investigations. We hope that these preliminary results on the use of SCS for production of TL and OSL materials are helpful to guide future efforts towards the development of new luminescence materials for different applications. - Highlights: Black-Right-Pointing-Pointer TL and OSL material produced with sensitivity similar to commercial materials. Black-Right-Pointing-Pointer Luminescence properties improved by Li co-doping and annealing. Black-Right-Pointing-Pointer The presence of atypical TL background and anomalous fading observed.

  4. Luminescence properties of Yb:Nd:Tm:KY3F10 nanophosphor and thermal treatment effects

    International Nuclear Information System (INIS)

    Gomes, Laércio; Linhares, Horácio Marconi da Silva M.D.; Ichikawa, Rodrigo Uchida; Martinez, Luis Gallego; Ranieri, Izilda Marcia

    2015-01-01

    In this work, we present the spectroscopic properties of KY 3 F 10 (KY3F) nanocrystals activated with thulium and codoped with ytterbium and neodymium ions. The most important processes that lead to the thulium upconversion emissions in the blue region were identified. A time-resolved luminescence spectroscopy technique was employed to measure the luminescence decays and to determine the most important mechanisms involved in the upconversion process that populates 1 G 4 (Tm 3+ ) excited states. Analysis of the energy-transfer processes dynamics using selective pulsed-laser excitations in Yb:Nd:Tm, Nd:KY3F nanocrystals shows that the direct energy transfer from Nd 3+ to Tm 3+ ions is the mechanism responsible for the 78% of the blue upconversion luminescence in the Yb:Nd:Tm:KY3F when compared with the Yb:Nd:Tm:KY3F bulk crystal for an laser excitation at 802 nm. An investigation of the 1 G 4 level luminescence kinetic of Tm 3+ in Yb/Nd/Tm system revealed that the luminescence efficiency ( 1 G 4 ) starts with a very low value (0.38%) for the synthesized nanocrystal (as grown) and strongly increases to 97% after thermal treatment at 550 °C for 6 h under argon flow. As a consequence of the thermal treatment at T=550 °C, the contributions of the (Nd×Tm) (Up 1 ) and (Nd×Yb×Tm) (Up 2 ) upconversion processes to the 1 G 4 luminescence are 33% (Up 1 ) and 67% for Up 2 . Up 2 process represented by Nd 3+ ( 4 F 3/2 )→Yb 3+ ( 2 F 7/2 ) followed by Yb 3+ ( 2 F 5/2 )→Tm ( 3 H 4 )→Tm 3+ ( 1 G 4 ) was previously reported as the main mechanism to produce the blue luminescence in Yb:Nd:Tm:YLiF 4 and KY 3 F 10 bulk crystals. Results of X-ray diffraction analysis of nanopowder using the Rietveld method reveled that crystallite sizes remain unchanged (12–14 nm) after thermal treatments with T≤400 °C, while the 1 G 4 luminescence efficiency strongly increases from 0.38% (T=25 °C) to 12% (T=400 °C). Results shown that the Nd 3+ ions distribution has a concentration

  5. A CMOS Luminescence Intensity and Lifetime Dual Sensor Based on Multicycle Charge Modulation.

    Science.gov (United States)

    Fu, Guoqing; Sonkusale, Sameer R

    2018-06-01

    Luminescence plays an important role in many scientific and industrial applications. This paper proposes a novel complementary metal-oxide-semiconductor (CMOS) sensor chip that can realize both luminescence intensity and lifetime sensing. To enable high sensitivity, we propose parasitic insensitive multicycle charge modulation scheme for low-light lifetime extraction benefiting from simplicity, accuracy, and compatibility with deeply scaled CMOS process. The designed in-pixel capacitive transimpedance amplifier (CTIA) based structure is able to capture the weak luminescence-induced voltage signal by accumulating photon-generated charges in 25 discrete gated 10-ms time windows and 10-μs pulsewidth. A pinned photodiode on chip with 1.04 pA dark current is utilized for luminescence detection. The proposed CTIA-based circuitry can achieve 2.1-mV/(nW/cm 2 ) responsivity and 4.38-nW/cm 2 resolution at 630 nm wavelength for intensity measurement and 45-ns resolution for lifetime measurement. The sensor chip is employed for measuring time constants and luminescence lifetimes of an InGaN-based white light-emitting diode at different wavelengths. In addition, we demonstrate accurate measurement of the lifetime of an oxygen sensitive chromophore with sensitivity to oxygen concentration of 7.5%/ppm and 6%/ppm in both intensity and lifetime domain. This CMOS-enabled oxygen sensor was then employed to test water quality from different sources (tap water, lakes, and rivers).

  6. Redox reactions and mechanism of luminescence in BaFCl:Eu

    CERN Document Server

    Upadeo, S V; Gundurao, T K

    1998-01-01

    The phenomenon of stimulable luminescence of phosphors pre-irradiated with high-energy radiation is widely used in the field of imaging. Phosphors such as BaFX:Eu (X = Cl, Br) are extensively used in x-ray screens for digital image processing. There is, however, divided opinion regarding the mechanism responsible for the luminescence process in these materials. In this paper we have discussed the role of Eu sup 3 sup +reversible Eu sup 2 sup + conversion in BaFCl:Eu phosphor using PL, TL, TL emission and ESR techniques. (author)

  7. Assembly and luminescence properties of lanthanide-polyoxometalates/polyethyleneimine/SiO{sub 2} particles with core–shell structure

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Jun, E-mail: junwang924@yahoo.com.cn; Fan, Shaohua; Zhao, Weiqian; Zhang, Hongyan

    2013-01-01

    In this paper, two lanthanide-polyoxometalate (LnW{sub 10}) complexes were bonded on the surface of the polyethyleneimine (PEI)-modified silica nanoparticles with different sizes, resulting in the formation of LnW{sub 10}/PEI/SiO{sub 2} particles. The hybrid core–shell particles were characterized by infrared, luminescent spectra, scanning electronic microscope, and transmission electronic microscope. The particles obtained exhibit the fine spherical core–shell structure and the excellent luminescence properties. The luminescence spectra studies revealed that the formation of LnW{sub 10}/PEI/SiO{sub 2} particles and the size of particle have an influence on the luminescence properties of lanthanide ions. - Highlights: ► SiO{sub 2}/polyethyleneimine (PEI) shows the chemisorption for Ln-polyoxometalates (LnW{sub 10}). ► The core-shell LnW{sub 10}/PEI/SiO{sub 2} nanoparticles with different sizes were fabricated. ► The hybrid particles exhibit the excellent luminescence properties. ► The sizes of particles affect the luminescence properties of lanthanide ions.

  8. Luminescence properties of different Eu sites in LiMgPO4:Eu2+, Eu3+

    International Nuclear Information System (INIS)

    Baran, A; Mahlik, S; Grinberg, M; Cai, P; Kim, S I; Seo, H J

    2014-01-01

    The effect of temperature on the luminescence properties of LiMgPO 4 doped with Eu 3+ and Eu 2+ are presented. Depending on the excitation wavelength, luminescence spectra consist of two distinct broad emission bands peaking at 380 nm and 490 nm related to 4f 6 5d 1  → 4f 7 ( 8 S 7/2 ) luminescence of Eu 2+ and to europium-trapped exciton, respectively, and/or several sharp lines between the 580 nm and 710 nm region, ascribed to the 5 D 0  →  7 F J (J = 0, 1, 2, 3 and 4) transitions in Eu 3+ . To explain all the features of the Eu 2+ and Eu 3+ luminescence we discussed the existence of two different Eu sites substituting for Li + , with short and long distance compensation. The evident effect of increasing the intensity of the Eu 2+ luminescence with increasing temperature was observed. It was considered that the charge compensation mechanism for Eu 3+ and Li + as well as Eu 2+ replacing Li + in the LiMgPO 4 is a long distance compensation that allows for the existence of some of the europium ions either as Eu 3+ at low temperature or as Eu 2+ at high temperature. We concluded that Eu 2+ in the Li + site with long distance compensation yields only 4f 6 5d 1  → 4f 7 luminescence, whereas Eu 2+ in the Li + site with short distance compensation yields 4f 6 5d 1  → 4f 7 luminescence and europium-trapped exciton emission. (paper)

  9. The problem of dating quartz 2: Synchrotron generated X-ray excited optical luminescence (XEOL) from quartz

    International Nuclear Information System (INIS)

    King, G.E.; Finch, A.A.; Robinson, R.A.J.; Taylor, R.P.; Mosselmans, J.F.W.

    2011-01-01

    The luminescence emission of quartz is used in optically stimulated luminescence dating (OSL), however the precise origins of the emission are unclear. A suite of quartz samples were analysed using X-ray excited optical luminescence (XEOL). Radiation dose effects were observed whereby the UV emissions (3.8 and 3.4 eV) were depleted to the benefit of the red emission (1.9-2.0 eV). Samples were excited at ∼7 keV. Understanding why some quartz emit light more brightly than others will increase the efficiency and precision of OSL analyses. - Highlights: → The X-ray excited optical luminescence (XEOL) emission of quartz is explored. → The XEOL of quartz of different provenances varies. → Radiation dosing causes UV emissions to deplete to the benefit of red emissions. → The 3.8 and 3.4 eV emissions deplete at the same rate. → The quartz luminescence emission exhibits anisotropic effects.

  10. Recombination luminescence from H centers and conversion of H centers into I centers in alkali iodides

    International Nuclear Information System (INIS)

    Berzina, B.J.

    1981-01-01

    The study is aimed at the search for H-plus-electron centers of luminescence and the investigation of the conversion of H- into I centers by the luminescence of H-plus-electron centers in alkali iodide crystals. KI, RbI and NaI crystals were studied at 12 K. H and F centers were created by irradiation with ultraviolet light corresponding to the absorption band of anion excitons. Then the excitation of electron centers by red light irradiation was followed. The spectra of stimulated recombination luminescence were studied. The luminescence of H-plus- electron centers had been observed and the conclusion was made that this center was formed on immobile H centers. In case of stable H centers the optically stimulated conversion of H centers into I centers occurs. The assumption is advanced on the spontaneous annihilation of near placed unstable F, H centers which leads to the creation of H-plus-electron luminescence centers and to the spontaneous H-I-centers conversion [ru

  11. The Response of the Ocean Thermal Skin Layer to Variations in Incident Infrared Radiation

    Science.gov (United States)

    Wong, Elizabeth W.; Minnett, Peter J.

    2018-04-01

    Ocean warming trends are observed and coincide with the increase in concentrations of greenhouse gases in the atmosphere resulting from human activities. At the ocean surface, most of the incoming infrared (IR) radiation is absorbed within the top micrometers of the ocean's surface where the thermal skin layer (TSL) exists. Thus, the incident IR radiation does not directly heat the upper few meters of the ocean. This paper investigates the physical mechanism between the absorption of IR radiation and its effect on heat transfer at the air-sea boundary. The hypothesis is that given the heat lost through the air-sea interface is controlled by the TSL, the TSL adjusts in response to variations in incident IR radiation to maintain the surface heat loss. This modulates the flow of heat from below and hence controls upper ocean heat content. This hypothesis is tested using the increase in incoming longwave radiation from clouds and analyzing vertical temperature profiles in the TSL retrieved from sea-surface emission spectra. The additional energy from the absorption of increasing IR radiation adjusts the curvature of the TSL such that the upward conduction of heat from the bulk of the ocean into the TSL is reduced. The additional energy absorbed within the TSL supports more of the surface heat loss. Thus, more heat beneath the TSL is retained leading to the observed increase in upper ocean heat content.

  12. Probing luminescence centers in Na rich feldspar

    DEFF Research Database (Denmark)

    Prasad, Amit Kumar; Lapp, Torben; Kook, Myung Ho

    2016-01-01

    our understanding of the luminescence mechanisms and recombination sites, in a sample of Na rich plagioclase feldspar (oligoclase). Both the UV and violet–blue emissions show resonant excitations arising from a distribution of energy levels. We propose, contrary to the general understanding...

  13. Negative luminescence and devices based on this phenomenon

    International Nuclear Information System (INIS)

    Ivanov-Omskii, V. I.; Matveev, B. A.

    2007-01-01

    Recent publications concerned with infrared emitters whose electrical modulation results in absorption of radiation detected as negative luminescence are reviewed. The main properties of the devices based on this phenomenon are analyzed

  14. Negative luminescence and devices based on this phenomenon

    Energy Technology Data Exchange (ETDEWEB)

    Ivanov-Omskii, V I; Matveev, B. A. [Russian Academy of Sciences, Ioffe Physicotechnical Institute (Russian Federation)], E-mail: bmat@iropt3.ioffe.rssi.ru

    2007-03-15

    Recent publications concerned with infrared emitters whose electrical modulation results in absorption of radiation detected as negative luminescence are reviewed. The main properties of the devices based on this phenomenon are analyzed.

  15. Towards Efficient Spectral Converters through Materials Design for Luminescent Solar Devices.

    Science.gov (United States)

    McKenna, Barry; Evans, Rachel C

    2017-07-01

    Single-junction photovoltaic devices exhibit a bottleneck in their efficiency due to incomplete or inefficient harvesting of photons in the low- or high-energy regions of the solar spectrum. Spectral converters can be used to convert solar photons into energies that are more effectively captured by the photovoltaic device through a photoluminescence process. Here, recent advances in the fields of luminescent solar concentration, luminescent downshifting, and upconversion are discussed. The focus is specifically on the role that materials science has to play in overcoming barriers in the optical performance in all spectral converters and on their successful integration with both established (e.g., c-Si, GaAs) and emerging (perovskite, organic, dye-sensitized) cell types. Current challenges and emerging research directions, which need to be addressed for the development of next-generation luminescent solar devices, are also discussed. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  16. Luminescence mechanism in doubly Gd, Nd-codoped fluoride crystals for VUV scintillators

    Czech Academy of Sciences Publication Activity Database

    Pejchal, Jan; Fukuda, K.; Babin, Vladimir; Kurosawa, S.; Yokota, Y.; Yoshikawa, A.; Nikl, Martin

    2016-01-01

    Roč. 169, Jan (2016), s. 682-689 ISSN 0022-2313. [International Conference on Luminescence and Optical Spectroscopy of Condensed Matter /17./. Wroclaw, 13.07.2014-18.07.2014] R&D Projects: GA MŠk(CZ) LH14266 Institutional support: RVO:68378271 Keywords : barium –lutetium–yttrium fluoride * lutetium fluoride * scintillator * VUV luminescence Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 2.686, year: 2016

  17. Luminescence properties of a nanoporous freshwater diatom.

    Science.gov (United States)

    Goswami, Bondita; Choudhury, Amarjyoti; Buragohain, Alak K

    2012-01-01

    Freshwater diatom frustules show special optical properties. In this paper we observed luminescence properties of the freshwater diatom Cyclotella meneghiniana. To confirm the morphological properties we present scanning electron microscopy (SEM) images. X-ray diffraction (XRD) studies were carried out to visualize the structural properties of the frustules, confirming that silica present in diatom frustules crystallizes in an α-quartz structure. Study of the optical properties of the silica frustules of diatoms using ultra-violet-visible (UV-vis) spectroscopy and photoluminescence spectroscopy confirmed that the diatom C. meneghiniana shows luminescence in the blue region of the electromagnetic spectrum when irradiated with UV light. This property of diatoms can be exploited to obtain many applications in day-to-day life. Also, using time-resolved photoluminescence spectroscopy (TRPL) it was confirmed that this species of diatom shows bi-exponential decay. Copyright © 2011 John Wiley & Sons, Ltd.

  18. New luminescence measurement facilities in retrospective dosimetry

    DEFF Research Database (Denmark)

    Lapp, Torben; Jain, Mayank; Thomsen, Kristina Jørkov

    2012-01-01

    ), this facility has been used to measure natural doses in feldspar using the decaying NIR RL signal.Secondly, we present a method for mapping radiation field of the built-in 90Sr/90Y β-source and estimating grain-location specific dose-rates. This is important for the accuracy of single grain results, when......This paper gives a review of recent developments in luminescence measurement facilities on the Risø TL/OSL reader including radio-luminescence (RL), exo-electron and violet stimulation attachments, and a method for characterising and if necessary correcting for beta irradiation source non...... radiation field is spatially non-uniform across the sample area. We document the effect of this correction method and further investigate on the effect of lifting the source to achieve a better dose-rate uniformity.Finally we summarise two recently-developed novel facilities to help investigate (i) the time...

  19. Luminescence of the SrCl2:Pr crystals under high-energy excitation

    International Nuclear Information System (INIS)

    Antonyak, O.T.; Voloshinovskii, A.S.; Vistovskyy, V.V.; Stryganyuk, G.B.; Kregel, O.P.

    2014-01-01

    The present research was carried out in order to elucidate the mechanisms of energy transfer from the crystal lattice to Pr 3+ ions in SrCl 2 . The luminescence excitation and emission spectra as well as luminescence kinetics of the SrCl 2 :Pr single crystals containing 0.2 mol% Pr were investigated at 300 and 10 K using the vacuum ultraviolet (VUV) synchrotron radiation. The X-ray excited luminescence spectra of the SrCl 2 :Pr (C Pr =0.2 and 0.5 mol%) and SrCl 2 :Pr, K (C Pr =1.5 mol%; C K =1.5 mol%) crystals were studied at 294 and 80 K. Under optical excitation of the samples in the Pr 3+ absorption bands, there were observed five fast ultraviolet emissions assigned to the 4f 1 5d→4f 2 transitions, and two long-wave bands corresponding to the f–f transitions. Furthermore, the intrinsic emission bands of SrCl 2 were observed at 10 K. The X-ray excited luminescence spectrum of the SrCl 2 :Pr crystal containing 0.2 mol% Pr, besides intrinsic emission band near 400 nm, has got a long-wave band at about 490 nm of the Pr 3+ centers. There were not observed any emission bands of the Pr 3+ centers corresponding to the 4f 1 5d–4f 2 transitions in the X-ray excited luminescence spectrum of the SrCl 2 :Pr crystal. The possible mechanisms of energy transfer from the SrCl 2 matrix to the Pr 3+ centers are discussed. -- Highlights: • Spectral-luminescent properties of SrCl 2 :Pr have been investigated. • The identification of emission 4f–4f and 5d–4f bands of Pr 3+ ions was performed. • Adding of potassium prevents clustering of the Pr 3+ centers in the SrCl 2 :Pr, K crystals. • Under X-ray excitation at 80–300 K only Pr 3+ 4f–4f and intrinsic emission is observed

  20. Luminescence studies on phosphor screens

    Energy Technology Data Exchange (ETDEWEB)

    Panayiotakis, G; Nomikos, C; Bakas, A; Proimos, B [Medical Physics Department, University of Patras, 265 00 Patras, Greece (Greece)

    1994-12-31

    We report our results on x-ray phosphor screens prepared of some new materials focusing attention on their efficiency under fluoroscopy conditions, on optimization conditions and on comparisons among the various materials. All data are presented in absolute values. A theoretical model is presented, that takes into account the granular structure of the screens, permitting the explanation and prediction of the luminescence properties of the screens. (authors). 12 refs, 3 figs.

  1. Electrostatic probes in luminescent discharges

    International Nuclear Information System (INIS)

    Cunha Raposo, C. da.

    1980-01-01

    A system to produce luminescent type plasma by continuos discharge and ionization by high frequency was constructed. The ionization was done in the air and in the argon under pressures from 3 to 10 mmHg. The parameters of a non magnetized collisional plasma and the parameters of a magnetized plasma such as, density, eletron temperature and potential, using a Langmuir probe with plane geometry, were determined. (M.C.K.) [pt

  2. Spectral-luminescent investigation of polymers doped with europium trisphenoyltrifluoroacetonate compound with 1,10-phenanthroline

    International Nuclear Information System (INIS)

    Karasev, V.E.; Mirochnik, A.G.; Shchelokov, R.N.

    1983-01-01

    Spectral-luminescent characteristics of europium tristhenoyltrifluoroacetonate with 1.10-phenanthpoline in polystyrepe and polyvinyl chloride are investigated. E 4 (TTA) 3 phen during introduction into polymers preserves its composition and structure. Weak temperature dependence of half-Width of luminescent lines qualitatively different from the case of crystal chelate is characteristic for polymers doped with E 4 (TTA) 3 xphen. Investigation into temperature dependence of E 4 3+ luminescent intensity in chelate doped polymers proves the conclusion on weakening processes of excitation energy relaxation by vibration constituents of close and far environment during chelate introduction into polymers

  3. Mitochondria Targeting with Luminescent Rhenium(I) Complexes.

    Science.gov (United States)

    Skiba, Joanna; Bernaś, Tytus; Trzybiński, Damian; Woźniak, Krzysztof; Ferraro, Giarita; Marasco, Daniela; Merlino, Antonello; Shafikov, Marsel Z; Czerwieniec, Rafał; Kowalski, Konrad

    2017-05-15

    Two new neutral fac -[Re(CO)₃(phen)L] compounds ( 1 , 2 ), with phen = 1,10-phenanthroline and L = O₂C(CH₂)₅CH₃ or O₂C(CH₂)₄C≡CH, were synthetized in one-pot procedures from fac -[Re(CO)₃(phen)Cl] and the corresponding carboxylic acids, and were fully characterized by IR and UV-Vis absorption spectroscopy, ¹H- and 13 C-NMR, mass spectrometry and X-ray crystallography. The compounds, which display orange luminescence, were used as probes for living cancer HeLa cell staining. Confocal microscopy revealed accumulation of both dyes in mitochondria. To investigate the mechanism of mitochondrial staining, a new non-emissive compound, fac -[Re(CO)₃(phen)L], with L = O₂C(CH₂)₃((C₅H₅)Fe(C₅H₄), i.e., containing a ferrocenyl moiety, was synthetized and characterized ( 3 ). 3 shows the same mitochondrial accumulation pattern as 1 and 2 . Emission of 3 can only be possible when ferrocene-containing ligand dissociates from the metal center to produce a species containing the luminescent fac -[Re(CO)₃(phen)]⁺ core. The release of ligands from the Re center was verified in vitro through the conjugation with model proteins. These findings suggest that the mitochondria accumulation of compounds 1 - 3 is due to the formation of luminescent fac -[Re(CO)₃(phen)]⁺ products, which react with cellular matrix molecules giving secondary products and are uptaken into the negatively charged mitochondrial membranes. Thus, reported compounds feature a rare dissociation-driven mechanism of action with great potential for biological applications.

  4. Luminescence properties of LiPrxCe1-xP4O12

    International Nuclear Information System (INIS)

    Shalapska, T.; Stryganyuka, G.; Trotsc, D.; Demkiv, T.; Gektin, A.; Voloshinovskii, A.; Dorenbos, P.

    2010-01-01

    LiPr 1-x Ce x P 4 O 12 (x=0, 0.002, 0.02; 0.1) powder samples were prepared using the melt solution technique. Luminescent parameters of LiPr 1-x Ce x P 4 O 12 phosphors have been investigated under ultraviolet-vacuum ultraviolet (3-12 eV) synchrotron radiation and X-rays excitation at room and near liquid He temperatures. Excitation luminescence spectra of Ce 3+ emission, luminescent spectra and decay curves from the lower excited state levels of the 4f 1 5d 1 and 5d 1 electronic configuration of the Pr 3+ and Ce 3+ , respectively, clearly indicate energy transfer from Pr 3+ to Ce 3+ . Energy migration proceeds via the Pr-sublattice followed by nonradiation transfer from Pr 3+ to Ce 3+ ions.

  5. Investigation of electro-optical properties for electrochemical luminescence device with a new electrode structure

    Science.gov (United States)

    Ok, Jung-Woo; Pooyodying, Pattarapon; Anuntahirunrat, Jirapat; Sung, Youl-Moon

    2018-04-01

    In this paper, we investigate electrochemical luminescent (ECL) device with a new structure and the ECL cell device with proposed electrode configuration works reliably at AC voltage. In particular, the conventional ECL cell has counter electrodes in which a cathode and an anode are opposed to each other, whereas the proposed structure has parallel electrodes in which a cathode and an anode are arranged on a single substrate. The proposed electrode configuration has a structural feature that electric short-circuiting is less likely to occur during bending than the conventional electrode configuration. The electro-optical characteristics of the new electrode configuration such as the current density, the light emission intensity, and the time evolution of the emission are investigated. The proposed ECL device exhibited higher light emitting efficiency than the conventional structure. Especially, at AC operation mode, the new structure showed the distinctive luminescence characteristic which is combined the first luminescence near the surface of electrode with the delayed second luminescence near the center of between electrodes. It was closely related to the behavior of luminescent particles. The proposed the ECL cell structure is expected to be utilized as a flexible display device by taking advantage of its characteristics and practicality.

  6. Tuning the luminescence of ZnO:Eu nanoparticles for applications in biology and medicine

    Science.gov (United States)

    Kaszewski, Jarosław; Kiełbik, Paula; Wolska, Ewelina; Witkowski, Bartłomiej; Wachnicki, Łukasz; Gajewski, Zdzisław; Godlewski, Marek; Godlewski, Michał M.

    2018-06-01

    Zinc oxide nanoparticles were synthesized with microwave hydrothermal technique and tested as luminescent contrast for biological imaging. Luminescence was activated by Eu3+ ions embedded in the nanoparticle matrix in the increasing concentrations of 1, 5 and 10 %mol. It was found that europium did not create a separate crystalline phase up to the concentration as high as 5 %mol. However, Eu3+ ions did not substitute Zn2+ in the host lattice, but allocated in the low symmetry environment. It was proposed that europium was locating in the inter-grain space or on the surface of nanoparticles. The luminescence intensity in ZnO:Eu, as well as the size of particles, increased with the Eu ion concentration. Moreover, in 10 %mol Eu sample, the separate phase of Eu-hydroxide was identified with crystals of micrometre length. Interestingly, in vivo study revealed, that contrary to the in silico experiments, following gastric gavage, the brightest nanoparticle-related luminescence signal was observed at 1 %mol. concentration of Eu. Since the alimentary uptake of nanoparticles was related to their size, we concluded that the increase in luminescence at 5 and 10 %mol. Eu concentrations was associated with the largest ZnO:Eu and Eu-hydroxide particles that did not cross the gastrointestinal barrier.

  7. Effect of concentrating and exposing the bioluminescent bacteria to the non-luminescent allo-bacterial extracellular products on their luminescence

    Digital Repository Service at National Institute of Oceanography (India)

    Ravindran, J.; Priya, G.G.; Kannapiran, E.

    of cell-cell physical contact will be high. In this study, the physical proximity was artificially enhanced between cells and the effect on luminescence in the concentrated cells in the normal culture medium and in the presence of other non-bacterial cell...

  8. Luminescence (IRSL) dating of Yeni Rabat church in Artvin, Turkey

    Science.gov (United States)

    Şahiner, Eren; Meriç, Niyazi; Uygun, Selda

    2013-05-01

    Luminescence dating is a chronological method that has been used extensively in terrestrial materials. In this study, we present Infrared Stimulated Luminescence (IRSL) dating results obtained for sediment and pottery samples taken from Yeni Rabat Church, Ardanuç, Artvin, Turkey. For this purpose, equivalent dose (ED) and annual dose rate (AD) of samples were measured. For annual dose rate, concentrations of radioactive isotopes (U, Th, K) were determined by using a high-purity germanium detector. For the equivalent dose, polymineral fine grain SAR (Single Aliquot Regenerative Dose) and MAAD (Multiple Aliquot Additive Dose) procedures were used. The optimal preheat temperature was determined for sediment and pottery samples. Ages were calculated by Aitken's luminescence age calculation method, which found 710±190 years for the pottery sample and 1450±370 years, 1390±420 years, 1430±310 years, 2210±520 years and 1640±390 years for different sediment samples, respectively. These estimated age ranges support the theory that Yeni Rabat Church could have been constructed in medieval times.

  9. Absorption and luminescence of crystalline quartz under electron nanosecond irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Gritsenko, B P; Lisitsyn, V M; Stepanchuk, V N [Tomskij Politekhnicheskij Inst. (USSR)

    1981-02-01

    The purpose of the study is continuation of investigations of principal regularities of production and destruction of short-lived defects in quartz and accompanying luminescence under electron pulse irradiation. For investigation purposes samples of crystalline synthetic quartz have been used. The irradiation has been performed at 80-400 K temperatures by means of an electron pulse accelerator with parameters: electron flow pulse duration 10 ns, pulse current density up to 1000 A/cm/sup 2/, electron mean energy 200 keV. Temperature-time characteristics of absorption and luminescence spectrum are studied. It has been found that quartz irradiation by electron pulses of nanosecond duration leads to appearance of short-lived bands of optical absorption at 4.1 and 5.15 eV to which by kinetic parameters correspond luminescence bands at 2.6 and 3.1 eV, respectively. The enumerated absorption bands are induced by quartz irradiation independently of the prehistory and phase state of the sample and are caused obviously by intrinsic radiation defects. Possible models of such defects are suggested.

  10. Optimization of Temperature Sensing with Polymer-Embedded Luminescent Ru(II Complexes

    Directory of Open Access Journals (Sweden)

    Nelia Bustamante

    2018-02-01

    Full Text Available Temperature is a key parameter in many fields and luminescence-based temperature sensing is a solution for those applications in which traditional (mechanical, electrical, or IR-based thermometers struggle. Amongst the indicator dyes for luminescence thermometry, Ru(II polyazaheteroaromatic complexes are an appealing option to profit from the widespread commercial technologies for oxygen optosensing based on them. Six ruthenium dyes have been studied, engineering their structure for both photostability and highest temperature sensitivity of their luminescence. The most apt Ru(II complex turned out to be bis(1,10-phenanthroline(4-chloro-1,10-phenanthrolineruthenium(II, due to the combination of two strong-field chelating ligands (phen and a substituent with electron withdrawing effect on a conjugated position of the third ligand (4-Clphen. In order to produce functional sensors, the dye has been best embedded into poly(ethyl cyanoacrylate, due to its low permeability to O2, high temperature sensitivity of the indicator dye incorporated into this polymer, ease of fabrication, and excellent optical quality. Thermosensitive elements have been fabricated thereof as optical fiber tips for macroscopic applications (water courses monitoring and thin spots for microscopic uses (temperature measurements in cell culture-on-a-chip. With such dye/polymer combination, temperature sensing based on luminescence lifetime measurements allows 0.05 °C resolution with linear response in the range of interest (0–40 °C.

  11. Paleodosimetrical properties of sodium alkali feldspars and problems of luminescence dating of sediments

    International Nuclear Information System (INIS)

    Huett, Galina; Jaek, Ivar

    1996-01-01

    Emission spectra of natural alkali feldspars extracted from sediments are studied using a CCD-camera based high sensitivity spectrometer. Applying a semiconductor laser (860± 1 nm), two dominant emission bands, blue (410 nm) and orange (570 nm), are revealed in infrared optically stimulated luminescence (IROSL) spectra for the most of the sediments from Scandinavian sections. Luminescence and dosimetric al properties of the hole traps, the induced orange emission band typical of sodium alkali feldspars are studied. As a result, high light bleach ability but low stability of the dosimetric al information lit sodium alkali feldspars are established. Problems of luminescence dating of sediments based on the mixture of potassium-sodium alkali feldspars are discussed. (author)

  12. Luminescent hybrid materials based on (8-hydroxyquinoline)-substituted metal-organic complexes and lead-borate glasses

    Science.gov (United States)

    Petrova, Olga B.; Anurova, Maria O.; Akkuzina, Alina A.; Saifutyarov, Rasim R.; Ermolaeva, Ekaterina V.; Avetisov, Roman I.; Khomyakov, Andrew V.; Taydakov, Ilya V.; Avetissov, Igor Ch.

    2017-07-01

    Novel luminescent organic-inorganic hybrid materials based on 8-hydroxyquinoline metal complexes (Liq, Kq, Naq, Rbq, Mgq2, Srq2, Znq2, Scq3, Alq3, Gaq3, and Inq3) have been synthesized by a high temperature exchange reaction with 80PbF2-20B2O3 inorganic low-melting glass. The mechanical and optical properties, transmission spectra, emission an excitation photoluminescence, and luminescence kinetic of hybrid materials were studied. All hybrid materials showed a wide luminescence band in the range 400-700 nm.

  13. Co-precipitation synthesis and upconversion luminescence ...

    Indian Academy of Sciences (India)

    ... light: strong green (539 nm), weak red (670 nm) and near-infrared (760 nm). The upconversion luminescence is based on two-photon absorption by the energy transfer from the donor (Yb3+) to the acceptor (Ho3+). All the results indicate that ZrO2:Yb3+-Ho3+ phosphors could be a promising biological labelling material.

  14. SPORT: A new sub-nanosecond time-resolved instrument to study swift heavy ion-beam induced luminescence - Application to luminescence degradation of a fast plastic scintillator

    Science.gov (United States)

    Gardés, E.; Balanzat, E.; Ban-d'Etat, B.; Cassimi, A.; Durantel, F.; Grygiel, C.; Madi, T.; Monnet, I.; Ramillon, J.-M.; Ropars, F.; Lebius, H.

    2013-02-01

    We developed a new sub-nanosecond time-resolved instrument to study the dynamics of UV-visible luminescence under high stopping power heavy ion irradiation. We applied our instrument, called SPORT, on a fast plastic scintillator (BC-400) irradiated with 27-MeV Ar ions having high mean electronic stopping power of 2.6 MeV/μm. As a consequence of increasing permanent radiation damages with increasing ion fluence, our investigations reveal a degradation of scintillation intensity together with, thanks to the time-resolved measurement, a decrease in the decay constant of the scintillator. This combination indicates that luminescence degradation processes by both dynamic and static quenching, the latter mechanism being predominant. Under such high density excitation, the scintillation deterioration of BC-400 is significantly enhanced compared to that observed in previous investigations, mainly performed using light ions. The observed non-linear behaviour implies that the dose at which luminescence starts deteriorating is not independent on particles' stopping power, thus illustrating that the radiation hardness of plastic scintillators can be strongly weakened under high excitation density in heavy ion environments.

  15. Raman and luminescence spectroscopy of zirconium oxide with the use of the MOLE microprobe

    International Nuclear Information System (INIS)

    Doyle, T.E.; Alvarez, J.L.

    1984-01-01

    Raman and luminescence spectroscopy with the use of the MOLE microprobe has been used to characterize ZrO 2 originating from oxidized fuel-rod cladding in nuclear accidents. Micro-Raman analysis of samples from Three Mile Island Unit 2 and the Power Burst Facility identified tetragonal and cubic ZrO 2 . The tetragonal and cubic phases are high-temperature polymorphs of ZrO 2 and provide information about temperatures and hydrogen formation in the TMI-2 core. The data suggest that the tetragonal ZrO 2 in TMI-2 samples was stabilized by a crystallite size effect, whereas cubic ZrO 2 in PBF debris samples was stabilized by impurities. Luminescence was used to differentiate yttria-stabilized ZrO 2 ceramics and oxidized fuel-rod cladding in PBF debris samples. The ZrO 2 ceramics produced strong, sharp luminescence peaks which indicated the presence of titanium and yttria in the ZrO 2 . Oxidized fuel-rod cladding displayed no luminescence

  16. Ion beam induced luminescence of germano-silicate optical fiber preform

    Energy Technology Data Exchange (ETDEWEB)

    Jung, Hyunkyu; Kim, Jongyeol; Lee, Namho [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of); Kim, Youngwoong; Han, Wontaek [Gwangju Institute of Science and Technology, Gwangju (Korea, Republic of); Markovic, Nikola; Jaksic, Milko [Ruder Boskovic Institute, Zagred (Croatia)

    2014-05-15

    When an optical fiber is exposed to radiation, the attenuation (RIA, Radiation Induced Attenuation) in the optical fiber (OF) is increased because of the color centers which deteriorate the transmission property and generate the absorption loss. In order to understand the radiation induced defect, Ion Beam induced luminescence (IBIL) was introduced to investigate it. IBIL technique is to analyze IR/VIS/UV luminescence related to ion beam interaction with outer shell electrons involved in chemical bonds and structure defects of target atoms. So IBIL is sensitive to its chemical composition and has been used in analysis of material characterization, geological samples and cultural heritage objects. In silica material, four O atoms are surrounding one Si atom in tetrahedral coordination. In this study, the influence of Copper (Cu) and Cerium (Ce) dopants to germano silica core optical fibers were investigated under proton irradiation at RBI using Ion Beam induced luminescence (IBIL) method. To understand the radiation induced defect of optical fibers, IBIL were tested to a germano-silica core fiber under 2 MeV proton irradiation. Although a Cu or Ce dopant was not detected by IBIL technique, the relation between the amount of radiation and luminescence can be established. This experiment showed a potential technique of studying the effects and behavior of additive elements for silica core fiber. To increase the radiation resistance of optical fibers, further investigations are needed, i. e. the proper additives and its contents and an interaction mechanism between Ge-related defects and additives.

  17. Ion beam induced luminescence of germano-silicate optical fiber preform

    International Nuclear Information System (INIS)

    Jung, Hyunkyu; Kim, Jongyeol; Lee, Namho; Kim, Youngwoong; Han, Wontaek; Markovic, Nikola; Jaksic, Milko

    2014-01-01

    When an optical fiber is exposed to radiation, the attenuation (RIA, Radiation Induced Attenuation) in the optical fiber (OF) is increased because of the color centers which deteriorate the transmission property and generate the absorption loss. In order to understand the radiation induced defect, Ion Beam induced luminescence (IBIL) was introduced to investigate it. IBIL technique is to analyze IR/VIS/UV luminescence related to ion beam interaction with outer shell electrons involved in chemical bonds and structure defects of target atoms. So IBIL is sensitive to its chemical composition and has been used in analysis of material characterization, geological samples and cultural heritage objects. In silica material, four O atoms are surrounding one Si atom in tetrahedral coordination. In this study, the influence of Copper (Cu) and Cerium (Ce) dopants to germano silica core optical fibers were investigated under proton irradiation at RBI using Ion Beam induced luminescence (IBIL) method. To understand the radiation induced defect of optical fibers, IBIL were tested to a germano-silica core fiber under 2 MeV proton irradiation. Although a Cu or Ce dopant was not detected by IBIL technique, the relation between the amount of radiation and luminescence can be established. This experiment showed a potential technique of studying the effects and behavior of additive elements for silica core fiber. To increase the radiation resistance of optical fibers, further investigations are needed, i. e. the proper additives and its contents and an interaction mechanism between Ge-related defects and additives

  18. Variables and potential models for the bleaching of luminescence signals in fluvial environments

    Science.gov (United States)

    Gray, Harrison J.; Mahan, Shannon

    2015-01-01

    Luminescence dating of fluvial sediments rests on the assumption that sufficient sunlight is available to remove a previously obtained signal in a process deemed bleaching. However, luminescence signals obtained from sediment in the active channels of rivers often contain residual signals. This paper explores and attempts to build theoretical models for the bleaching of luminescence signals in fluvial settings. We present two models, one for sediment transported in an episodic manner, such as flood-driven washes in arid environments, and one for sediment transported in a continuous manner, such as in large continental scale rivers. The episodic flow model assumes that the majority of sediment is bleached while exposed to sunlight at the near surface between flood events and predicts a power-law decay in luminescence signal with downstream transport distance. The continuous flow model is developed by combining the Beer–Lambert law for the attenuation of light through a water column with a general-order kinetics equation to produce an equation with the form of a double negative exponential. The inflection point of this equation is compared with the sediment concentration from a Rouse profile to derive a non-dimensional number capable of assessing the likely extent of bleaching for a given set of luminescence and fluvial parameters. Although these models are theoretically based and not yet necessarily applicable to real-world fluvial systems, we introduce these ideas to stimulate discussion and encourage the development of comprehensive bleaching models with predictive power.

  19. Fabrication and characterization of dual-functional ultrafine composite fibers with phase-change energy storage and luminescence properties.

    Science.gov (United States)

    Xi, Peng; Zhao, Tianxiang; Xia, Lei; Shu, Dengkun; Ma, Menjiao; Cheng, Bowen

    2017-01-09

    Ultrafine composite fibers consisting of a thermoplastic polyurethane solid-solid phase-change material and organic lanthanide luminescent materials were prepared through a parallel electrospinning technique as an innovative type of ultrafine, dual-functional fibers containing phase-change and luminescent properties. The morphology and structure, thermal energy storage, and luminescent properties of parallel electrospun ultrafine fibers were investigated. Scanning electron microscopy (SEM) images showed that the parallel electrospun ultrafine fibers possessed the desired morphologies with smaller average fiber diameters than those of traditional mixed electrospun ultrafine fibers. Transmission electron microscopy (TEM) images revealed that the parallel electrospun ultrafine fibers were composed of two parts. Polymeric phase-change materials, which can be directly produced and spun, were used to provide temperature stability, while a mixture of polymethyl methacrylate and an organic lanthanide complex acted as the luminescent unit. Differential scanning calorimetry (DSC) and luminescence measurements indicated that the unique structure of the parallel electrospun ultrafine fibers provides the products with good thermal energy storage and luminescence properties. The fluorescence intensity and the phase-change enthalpy values of the ultrafine fibers prepared by parallel electrospinning were respectively 1.6 and 2.1 times those of ultrafine fibers prepared by mixed electrospinning.

  20. Luminescence, virulence and quorum sensing signal production by pathogenic Vibrio campbellii and Vibrio harveyi isolates.

    Science.gov (United States)

    Defoirdt, T; Verstraete, W; Bossier, P

    2008-05-01

    To study the relationship between luminescence, autoinducer production and virulence of pathogenic vibrios. Luminescence, quorum sensing signal production and virulence towards brine shrimp nauplii of 13 Vibrio campbellii and Vibrio harveyi strains were studied. Although only two of the tested strains were brightly luminescent, all of them were shown to produce the three different types of quorum sensing signals known to be produced by Vibrio harveyi. Cell-free culture fluids of all strains significantly induced bioluminescence in the cholerae autoinducer 1, autoinducer 2 and harveyi autoinducer 1 reporter strains JAF375, JMH597 and JMH612, respectively. There was no relation between luminescence and signal production and virulence towards brine shrimp. There is a large difference between different strains of Vibrio campbellii and Vibrio harveyi with respect to bioluminescence. However, this is not reflected in signal production and virulence towards gnotobiotic brine shrimp. Moreover, there seems to be no relation between quorum sensing signal production and virulence towards brine shrimp. The results presented here indicate that strains that are most brightly luminescent are not necessarily the most virulent ones and that the lower virulence of some of the strains is not due to a lack of autoinducer production.

  1. Persistent luminescence and thermoluminescence of UV/VIS -irradiated SrAl2O4: Eu2+, Dy3+ phosphor

    International Nuclear Information System (INIS)

    Pereyda-Pierre, C.; Meléndrez, R.; García, R.; Pedroza-Montero, M.; Barboza-Flores, M.

    2011-01-01

    The persistent luminescence and thermoluminescence properties of SrAl 2 O 4 : Eu 2+ , Dy 3+ phosphors excited with UV–VIS light in the 200–500 nm region were investigated. The thermoluminescence glow curve was found to be composed of peaks around 70, 125 and 245 °C. The persistent luminescence and thermoluminescence excitation spectra exhibited a broad band around 300–500 nm centered at 400 and 420 nm respectively. A linear behavior of the integrated thermoluminescence intensity and persistent luminescence versus irradiation time was found for the first 60 s. The charge detrapping from the 70 °C trapping levels was the major contributor to the observed persistent luminescence at room temperature. The SrAl 2 O 4 : Eu 2+ , Dy 3+ phosphors have suitable properties to be applied as storage and persistent luminescence UV–VIS irradiation dose phosphor. -- Highlights: ► SrAl 2 O 4 :Eu 2+ , Dy 3+ persistent luminescence and thermoluminescence was measured. ► The phosphor was irradiated with UV–VIS photons in the 200–500 nm wavelength range. ► SrAl 2 O 4 :Eu 2+ , Dy 3+ behaves adequately as persistent and storage UV–VIS dosimeter. ► The persistent luminescence dosimetry does not require heat or light stimulation.

  2. Remote forcing annihilates barrier layer in southeastern Arabian Sea

    Digital Repository Service at National Institute of Oceanography (India)

    Shenoi, S.S.C.; Shankar, D.; Shetye, S.R.

    - surements were made every two hours and have been l- tered with a 25-hour running mean. -12 -8 -4 0 4 8 12 MSLA (TSL) MSLA (coast) Sea level (cm) | | | | | 150 155 160 165 170 175 Dyn. height (cm)Dyn. ht. (TSL) 0 4 8 12 Wind speed (ms -1 ) Wind (TSL) Wind...

  3. Identifying well-bleached quartz using the different bleaching rates of quartz and feldspar luminescence signals

    DEFF Research Database (Denmark)

    Murray, A.S.; Thomsen, Kristina Jørkov; Masuda, N.

    2012-01-01

    When dating older sedimentary deposits using quartz, there are no unambiguous methods for identifying the presence of incomplete bleaching. Current statistical analysis of dose distributions depends entirely on the assumption that incomplete bleaching and mixing are the main causes of any excess...... dispersion in the distribution; the only existing way to test this assumption is using independent age control. Here we suggest a new approach to this question, based on the differential bleaching rates of quartz and feldspar luminescence signals. We first present data that confirm the differences...... in relative bleaching rates of quartz optically stimulated luminescence (OSL) and feldspar luminescence stimulated at 50 °C by infrared light (IR50) and feldspar luminescence stimulated at 290 °C by infrared light after a stimulation at 50 °C (pIRIR290), and use recently deposited samples to determine...

  4. Device for the evaluation of radio-photo-luminescent glasses

    International Nuclear Information System (INIS)

    Hoegl, A.; Schubert, K.

    1979-01-01

    The UV light for irradiation of the glass as well as the luminescent light generated by the UV light are recorded in different measuring circuits. Intensity variations of the UV light source are corrected by a programmed control system and a comparing and correcting device linking both measuring circuits with one another and containing integrating stages as well as a-d converters. In order to eliminate the influence of sensitivity variations of the light converter and of the amplifying level of the succeeding amplifier a reference light source is added to the light converter. The programmed control system causes alternating measuring phases of luminescence and reference light. The correction is done by the comparing and correcting unit. (DG) [de

  5. Studies of positron induced luminescence from polymers

    International Nuclear Information System (INIS)

    Xu, J.; Hulett, L.D. Jr.; Lewis, T.A.; Tolk, N.H.

    1994-01-01

    Light emission from polymers (anthracene dissolved in polystryrene) induced by low-energy positrons and electrons has been studied. Results indicate a clear difference between optical emissions under positron and electron bombardment. The positron-induced luminescence spectrum is believed to be generated by both collisional and annihilation processes

  6. Luminescence of nanocrystalline ZnSe:Mn2+

    NARCIS (Netherlands)

    Suyver, J.F.; Wuister, S.F.; Kelly, J.J.; Meijerink, A.

    2000-01-01

    The luminescence properties of nanocrystalline ZnSe:Mn^(2+) prepared via an inorganic chemical synthesis are described. Photoluminescence spectra show distinct ZnSe and Mn^(2+) related emissions, both of which are excited via the ZnSe host lattice. The Mn^(2+) emission wavelength and the

  7. The effect of Bi3+ and Li+ co-doping on the luminescence characteristics of Eu3+-doped aluminum oxide films

    International Nuclear Information System (INIS)

    Padilla-Rosales, I.; Martinez-Martinez, R.; Cabañas, G.; Falcony, C.

    2015-01-01

    The incorporation of Bi 3+ and Li + as co-dopants in Eu 3+ -doped aluminum oxide films deposited by the ultrasonic spray pyrolysis technique and its effect on the luminescence characteristics of this material are described. Both Bi 3+ and Li + do not introduce new luminescence features but affect the luminescence intensity of the Eu 3+ related emission spectra as well as the excitation spectra. The introduction of Bi 3+ generates localized states in the aluminum oxide host that result in a quenching of the luminescence intensity, while Li + and Bi 3+ co-doping increase the luminescence intensity of these films. - Highlights: • Li and Bi co-doping increase the luminescence. • Bi creates localized states in the Al 2 O 3 host. • Li was incorporated as a co-activator

  8. Renewable energy : better luminescent solar panels in prospect

    NARCIS (Netherlands)

    Debije, M.G.

    2015-01-01

    Devices known as luminescent solar concentrators could find use as renewable-energy generators, but have so far been plagued by a major light-reabsorption effect. A new study offers a promising route to tackling this problem

  9. Synthesis of porous silicon nano-wires and the emission of red luminescence

    International Nuclear Information System (INIS)

    Congli, Sun; Hao, Hu; Huanhuan, Feng; Jingjing, Xu; Yu, Chen; Yong, Jin; Zhifeng, Jiao; Xiaosong, Sun

    2013-01-01

    This very paper is focusing on the characterization of porous silicon nano-wires prepared via a two-step route, the electroless chemical etching and the following post-treatment of HF/HNO 3 solution. Hence, scanning electron microscopy, transmission electron microscopy and confocal fluorescence microscopy are employed for this purpose. From the results of experiments, one can find that the as-prepared silicon nano-wire is of smooth surface and that no visible photo-luminescence emission could be seen. However, the porous structure can be found in the silicon nano-wire treated with HF/HNO 3 solution, and the clear photo-luminescence emission of 630 nm can be recorded with a confocal fluorescence microscope. The transmission electron microscopy test tells that the porous silicon nano-wire is made up of a porous crystalline silicon nano-core and a rough coating of silicon oxide. Besides, based on the post-HF- and -H 2 O 2 - treatments, the emission mechanism of the red luminescence has been discussed and could be attributed to the quantum confinement/luminescence center model which could be simply concluded as that the electron–hole pairs are mainly excited inside the porous silicon nano-core and then tunneling out and recombining at the silicon oxide coating.

  10. Synthesis of porous silicon nano-wires and the emission of red luminescence

    Energy Technology Data Exchange (ETDEWEB)

    Congli, Sun [School of Materials Science and Engineering, Sichuan University (China); Hao, Hu [National Engineering Research Center for Biomaterials, Sichuan University, Chengdu 610064, Sichuan (China); Huanhuan, Feng; Jingjing, Xu; Yu, Chen; Yong, Jin; Zhifeng, Jiao [School of Materials Science and Engineering, Sichuan University (China); Xiaosong, Sun, E-mail: sunxs@scu.edu.cn [School of Materials Science and Engineering, Sichuan University (China)

    2013-10-01

    This very paper is focusing on the characterization of porous silicon nano-wires prepared via a two-step route, the electroless chemical etching and the following post-treatment of HF/HNO{sub 3} solution. Hence, scanning electron microscopy, transmission electron microscopy and confocal fluorescence microscopy are employed for this purpose. From the results of experiments, one can find that the as-prepared silicon nano-wire is of smooth surface and that no visible photo-luminescence emission could be seen. However, the porous structure can be found in the silicon nano-wire treated with HF/HNO{sub 3} solution, and the clear photo-luminescence emission of 630 nm can be recorded with a confocal fluorescence microscope. The transmission electron microscopy test tells that the porous silicon nano-wire is made up of a porous crystalline silicon nano-core and a rough coating of silicon oxide. Besides, based on the post-HF- and -H{sub 2}O{sub 2}- treatments, the emission mechanism of the red luminescence has been discussed and could be attributed to the quantum confinement/luminescence center model which could be simply concluded as that the electron–hole pairs are mainly excited inside the porous silicon nano-core and then tunneling out and recombining at the silicon oxide coating.

  11. Cerenkov luminescence tomography based on preconditioning orthogonal matching pursuit

    Science.gov (United States)

    Liu, Haixiao; Hu, Zhenhua; Wang, Kun; Tian, Jie; Yang, Xin

    2015-03-01

    Cerenkov luminescence imaging (CLI) is a novel optical imaging method and has been proved to be a potential substitute of the traditional radionuclide imaging such as positron emission tomography (PET) and single-photon emission computed tomography (SPECT). This imaging method inherits the high sensitivity of nuclear medicine and low cost of optical molecular imaging. To obtain the depth information of the radioactive isotope, Cerenkov luminescence tomography (CLT) is established and the 3D distribution of the isotope is reconstructed. However, because of the strong absorption and scatter, the reconstruction of the CLT sources is always converted to an ill-posed linear system which is hard to be solved. In this work, the sparse nature of the light source was taken into account and the preconditioning orthogonal matching pursuit (POMP) method was established to effectively reduce the ill-posedness and obtain better reconstruction accuracy. To prove the accuracy and speed of this algorithm, a heterogeneous numerical phantom experiment and an in vivo mouse experiment were conducted. Both the simulation result and the mouse experiment showed that our reconstruction method can provide more accurate reconstruction result compared with the traditional Tikhonov regularization method and the ordinary orthogonal matching pursuit (OMP) method. Our reconstruction method will provide technical support for the biological application for Cerenkov luminescence.

  12. Temperature, stress, and annealing effects on the luminescence from electron-irradiated silicon

    Science.gov (United States)

    Jones, C. E.; Johnson, E. S.; Compton, W. D.; Noonan, J. R.; Streetman, B. G.

    1973-01-01

    Low-temperature photoluminescence spectra are presented for Si crystals which have been irradiated with high-energy electrons. Studies of isochronal annealing, stress effects, and the temperature dependences of the luminescence are used to discuss the nature of the luminescent transitions and the properties of defects. Two dominant bands present after room-temperature anneal of irradiated material are discussed, and correlations of the properties of these bands are made with known Si defects. A band between 0.8 and 1.0 eV has properties which are related to those of the divacancy, and a band between 0.6 and 0.8 eV has properties related to those of the Si-G15(K) center. Additional peaks appear in the luminescence after high-temperature anneal; the influence of impurities and the effects of annealing of these lines are discussed.

  13. Luminescent Eosin Y–SiO2 hybrid nano and microrods prepared by sol–gel template method

    International Nuclear Information System (INIS)

    Secu, M.; Secu, C.E.; Sima, M.; Negrea, R.F.; Bartha, C.; Dinescu, M.; Damian, V.

    2013-01-01

    Sol–gel chemistry within the pores of a polycarbonate template membrane was used for the preparation of Eosin Y–SiO 2 hybrid nano- and microrods, using tetraethylorthosilicate [TEOS, Si(OC 2 H 5 ) 4 ] as the precursor in the presence of trifluoroacetic acid (TFA) catalyst. The ethanolic solution of Eosin-Y was added to the silica sol to trap dye molecules inside the SiO 2 gel network during the gelation. Structural and morphological characterization using scanning electron microscopy (SEM) and luminescence microscopy have shown the formation of rods with 200 nm and 1.2 μm diameter and about 30 μm length, exhibiting luminescence properties. Spectroscopic characterization has shown that the luminescence is due to Eosin-Y molecule in the xerogel porous network, surrounded by a solvation shell given mainly by the water. -- Highlights: • Sol–gel template method was used to prepare Eosin Y–SiO 2 hybrid rods-type structures. • Morphological characterization has shown nano- and microrods with luminescent properties. • Luminescence is due to Eosin-Y molecule surrounded by a solvation shell given by water

  14. Luminescence evolution from alumina ceramic surface before flashover under direct and alternating current voltage in vacuum

    Energy Technology Data Exchange (ETDEWEB)

    Su, Guo-Qiang; Wang, Yi-Bo; Song, Bai-Peng; Mu, Hai-Bao, E-mail: haibaomu@xjtu.edu.cn, E-mail: gjzhang@xjtu.edu.cn; Zhang, Guan-Jun, E-mail: haibaomu@xjtu.edu.cn, E-mail: gjzhang@xjtu.edu.cn [State Key Laboratory of Electrical Insulation and Power Equipment, School of Electrical Engineering, Xi’an Jiaotong University, Xi’an, Shaanxi 710049 (China); Li, Feng; Wang, Meng [Institute of Fluid Physics, China Academy of Engineering Physics, Mianyang, Sichuan 621900 (China)

    2016-06-15

    The luminescence evolution phenomena from alumina ceramic surface in vacuum under high voltage of direct and alternating current are reported, with the voltage covering a large range from far below to close to the flashover voltage. Its time resolved and spatial distributed behaviors are examined by a photon counting system and an electron-multiplying charge-coupled device (EMCCD) together with a digital camera, respectively. The luminescence before flashover exhibits two stages as voltage increasing, i.e., under a relative low voltage (Stage A), the luminescence is ascribed to radiative recombination of hetero-charges injected into the sample surface layer by Schottky effect; under a higher voltage (Stage B), a stable secondary electron emission process, resulting from the Fowler-Nordheim emission at the cathode triple junction (CTJ), is responsible for the luminescence. Spectrum analysis implies that inner secondary electrons within the surface layer of alumina generated during the SSEE process also participate in the luminescence of Stage B. A comprehensive interpretation of the flashover process is formulated, which might promote a better understanding of flashover issue in vacuum.

  15. Laser-induced incandescence of suspended particles as a source of excitation of dye luminescence

    CERN Document Server

    Zelensky, S

    2003-01-01

    The interaction of pulsed YAG-Nd sup 3 sup + laser radiation with submicron light-absorbing particles suspended in an aqueous solution of Rhodamine 6G is investigated experimentally. The experiments demonstrate that the laser-induced incandescence of suspended particles excites the luminescence of the dissolved dye molecules. The mechanism of the luminescence excitation consists in the reabsorption of the thermal radiation within the volume of the sample cell. On the ground of this mechanism of excitation, a method of measurement of the luminescence quantum yield is proposed and realized. The method requires the knowledge of the geometrical parameters of the cell and does not require the use of reference samples.

  16. Basic study on electrically stimulated luminescence (ESL) as a dosimetry and dating method

    International Nuclear Information System (INIS)

    Sato, H.; Yamanaka, C.; Ikeya, M.

    2003-01-01

    Electrically stimulated luminescence (ESL) of calcium carbonate has been studied for application as dosimetry and dating. A powdered calcium carbonate was sandwiched by electrodes, which supplied electric field. Luminescence and surface current through a powdered sample were measured using a photomultiplier and a digital multimeter, respectively. A linear dependence of ESL on the absorbed dose by γ-rays was found when the applied voltage was below the breakdown threshold. Reciprocal electric charges through the sample had also linear relation with the absorbed dose. We propose that the luminescence and electric charge under intense electric field in calcium carbonate become new methods for dosimetry and dating on the basis of the surface defects of the calcium carbonate grains produced by the irradiation of γ-rays

  17. Linear luminescence for thin plastic scintillator under intense soft X-ray irradiation

    International Nuclear Information System (INIS)

    Ning Jiamin; Jiang Shilun; Xu Rongkun; Guo Cun

    2006-01-01

    The basic principle of soft X-ray power meter is introduced in the paper and the experimental process and the result of thin plastic scintillator linear luminescence under intense soft X-ray irradiation are described. A range of flux density of energy for thin plastic scintillator linear luminescence under intense soft X-ray irradiation is included. The upper limit of the flux density is 1.47 x 10 5 W/cm 2 . (authors)

  18. Time-resolved luminescence of Eu2+-aggregate centers in CsBr crystals

    International Nuclear Information System (INIS)

    Zorenko, Yu.V.; Turchak, R.M.; Voznjak, T.I.; Stryganjuk, G.B.

    2005-01-01

    The luminescence of Eu 2+ -V Cs dipole centers and CsEuBr 3 aggregate centers, as well as the features of the energy transfer to these centers by excitons have been studied in CsBr:Eu crystals by means of investigation of the time-resolved emission spectra and luminescence decay kinetics under excitation by synchrotron radiation at RT. (copyright 2005 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  19. Theory of photoresistors on the base of trapezoidal δ-doped superlattices

    International Nuclear Information System (INIS)

    Osipov, V.V.; Selyakov, A.Yu.; Foygel, M.

    1999-01-01

    A theory of far infrared photoresistors that is based on trapezoidal δ-doped superlattices (TSL) has been developed. It is shown that photoconductivity of TSL in monopolar despite the interband absorption and generation of electron - hole pairs. In this way, photoelectric gain and responsivity of TSL photoresistor can reach gigantic values. It is established that tunneling-radiative lifetime of electron-hole pairs determines the kinetics of photoconductivity decay. It is shown that a surprising effect takes place: voltage responsivity does not depend virtually on lifetime of nonequilibrium carriers and on the doping level of TSL photoresistor and can reach gigantic values [ru

  20. Pottery versus sediment: Optically stimulated luminescence dating of the Neolithic Vinča culture, Serbia

    DEFF Research Database (Denmark)

    Bate, Stephen; Stevens, Thomas; Buylaert, Jan-Pieter

    2017-01-01

    Optically stimulated luminescence (OSL) dating was applied to the Neolithic Vinča culture's type-site, Vinča Belo-Brdo, to establish best protocols for routine luminescence dating of similar Holocene sites, critical in understanding Neolithic to Chalcolithic cultural development. Equivalent dose ...