... (2) SJ Hale and L. A. Melton, "Absolute Quantum Yields for Exciplex Fluorescence", Applied Spectroscopy, 44, 101 (1990). ...

... transition energies, the fluorescence lifetime and the fluorescence quantum yield of BChl-ser on the solvent tested. ... to calculate the absolute values of the fluorescence quantum yields Φfl in other so...

A new technique of photoacoustic spectroscopy measurements of the absolute fluorescence quantum yields has been investigated and used in laser dye solutions. The fluorescence quenchers is used in the experiment. Five home-made dyes, Rhodamine 6G, Disodium Fluorescein, Eosin Y, Cuomarin 1 and Quinine Bisulphate, ...

One of the goals of the AIRFLY (AIR FLuorescence Yield) experiment is to measure the absolute fluorescence yield induced by electrons in air to better than 10% precision. We introduce a new technique for measurement of the absolute fluorescence ...

Photothermal spectroscopies and fluorimetry have been used to determine absolute and relative fluorescence quantum yields for cresyl violet perchlorate in methanolic and aqueous solutions as a function of concentration. The concentration dependence of the fluorescence quantum yield is found to ...

The rate constants for the decay of ultraviolet fluorescence from liquid butane, pentane, and hexane have been measured as a function of temperature between their respective freezing points and near-room temperature. The rate constants are well characterized as the sum of an activated and nonactivated term, as has been described previously. The parameters determining the rate ...

The fluorescence quantum yields of solutions of 4-dimethylaminochalcone (DMC) in a series of individual solvents of different chemical nature have been measured using a technique based on studying the kinetics of fluorescence decay. A new quantitative regularity, namely, the dependence of the fluorescence quantum ...

We have performed a measurement of the absolute yield of fluorescence photons at the Fermilab Test Beam. A systematic uncertainty at 5% level was achieved by the use of Cherenkov radiation as a reference calibration light source. A cross-check was performed by an independent calibration using a laser light source. A significant ...

The fluorescence quantum efficiency of oxazine 1 perchlorate in 1,2-dichloroethane was measured with photoacoustic spectroscopy in which fluorescence quenching was used. The measurement shows that the relation between the fluorescence quantum efficiency and the concentration of solution of oxazine 1 in 1.2-dichloroethane is obviously ...

High-energy cosmic rays with energies exceeding $10^{17}$ eV are frequently observed by measurements of the fluorescence light induced by air showers. A major contribution to the systematic uncertainties of the absolute energy scale of such experiments is the insufficient knowledge of the fluorescence light yield ...

The fluorescence yield was determined for the Ar L shell by measuring absolute cross sections for Ar L x-ray and Auger-electron emission for 30- to 600- keV H+, H/sub 2/+, and He+ ions on Ar. When the Auger-electron spectrum was analyzed, the fluorescence yield for He+ was found to be an ...

The nitrogen fluorescence induced in air is used to detect ultra-high-energy cosmic rays (UHECR) and to measure their energy. The precise knowledge of the absolute fluorescence yield is the key quantity to improve the accuracy on the cosmic ray energy. The total yield has been measured in dry ...

We describe a new optical detection technique, termed "spatially modulated fluorescence emission," that delivers high signal-to-noise discrimination without precision optics to enable a flow cytometer that can combine high performance, robustness, compactness, low cost, and ease of use. The detection technique is demonstrated with measurements of absolute ...

... the photon yields in the ... Descriptors : *CHEMICAL REACTIONS, *PHOTONS, *CHEMILUMINESCENCE ... LASERS, FLUORINE, YIELD, NITROGEN ...

Theoretical K-shell fluorescence yields for various electronic configurations of neon are presented. These fluorescence yields are averages of the level fluorescence yields with a statistical population. (Author)

The air-fluorescence yield is a key parameter for determining the energy scale of ultra-high-energy cosmic rays detected by fluorescence telescopes. A compilation of the available measurements of the absolute air-fluorescence yield normalized to its value in photons per MeV ...

The rate constant is measured over the temperature interval 218-456 K using the technique of flash photolysis-laser-induced fluorescence. NH2 radicals are produced by the flash photolysis of ammonia highly diluted in argon, and the decay of fluorescent NH...

A procedure is described for obtaining quantilative analysis of trace elements in a thick sample by heavy-ion-induced x-ray fluorescence. preparing thin uniform samples and yields absolute abundances of impurity elements without utilizing internal standards. (auth)

Using quinine sulfate in 0.1 N sulfuric acid as a standard during the spectroscopic study of purines (1), it was found that 2-aminopurine in neutral solution at 160�K has a fluorescence quantum yield which is about 2.5 times that of quinine sulfate at room temperature. Thus, the widely used value of 0.55 published for the absolute ...

... Title : THE ABSOLUTE QUANTUM YIELD DUE TO THE INTERNAL PHOTOELECTRIC EFFECT IN CHEMICALLY-DEPOSITED PbS FILMS,. ...

The absolute rate constant for the reaction Cl + H2CO yields HCl + HCO was determined by the flash-photolysis resonance fluorescence method to be 7.5 plus or minus 0.9 (2 sigma) times 10 to the minus 11th power cu cm/molecule sec at 298 K and to have a ne...

Classifications of Auger electrons, their energies, relative intensities of lines and groups of Auger electrons, and the absolute magnitude of Auger effect probabilities (energy width) are reviewed and analyzed. The saturated part of primary vacancies emitting Auger electrons (the Auger yield) and the part emitting x radiation (the ...

A method for measuring the photoluminescent quantum yields (PLQY) of luminescent organic dyes is presented. The self-absorption probability calculated at different dye concentrations is used to determine the absolute quantum yield from the observed values. The results for a range of commercially available dyes show high quantum ...

Laser-induced fluorescence spectroscopy can provide a highly sensitive and selective means of atomic and ionic impurity detection. Because the photodetector can be physically isolated from the laser-excited region, these techniques can be applied to monitoring in hostile environments. The basic concepts behind fluorescence detection are reviewed. Saturated ...

For the calorimetric determination of the primary energy of extensive air showers, measured by fluorescence telescopes, a precise knowledge of the conversion factor (fluorescence yield) between the deposited energy in the atmosphere and the number of emitted fluorescence photons is essential. The ...

... Comparison of the Absolute Quantum Yields of the ... from the O/NO gas phase reaction ... and the luminol chemiluminescence quantum yield lead to ...

The construction and performance of a wall-less multiwire proportional counter (MWPC) is described. The absolute emission rate of M x rays from a sup 241 Am source was measured with the MWPC and with a single-wire proportional counter and a value of (6.35...

The techniques of isothermal calorimetry (for H atoms) and laser-induced fluorescence (for HCl(1)) were combined to yield absolute rate coefficients for H and D atom removal of HCl(1) and DCl(1). At T = 295 K, the rate coefficients for H + HCl(1), D + HCl...

The rate constant for the reaction Br + O3 yields BrO + O2 was measured from 200 to 360 K by the technique of flash photolysis coupled to time resolved detection of bromine atoms by resonance fluorescence (FP-RF). Br atoms were produced by the flash photo...

The rate parameters for the reaction of O(3P) with carbonyl sulfide, O(3P) + OCS yields CO + SO have been determined directly by monitoring O(3P) using the flash photolysis-resonance fluorescence technique. The value for k sub 1 was measured over a temper...

Low levels of NO sub 3 were maintained in an ozone-free system by carefully controlled unimolecular thermal decomposition of N sub 2 O sub 5 in N sub 2 at a total pressure of 10 torr. N sub 2 O sub 5 (and HNO sub 3 ) concentrations were measured by infrar...

Experimental results of the absolute air-fluorescence yield are given very often in different units (photons/MeV or photons/m) and for different wavelength intervals. In this work we present a comparison of available results normalized to its value in photons/MeV for the 337 nm band at 1013 hPa and 293 K. The conversion of photons/m to ...

... Report Date : 23 AUG 1972. Pagination or Media Count : 28. Abstract : Absolute electron yields from tantalum, molybdenum, copper and aluminum ...

... entitled 'X-Ray Fluorescence Yields and ... NUCLEAR CHEMISTRY ATOMIC AND MOLECULAR PHYSICS AND SPECTROSCOPY. ...

... The characteristics red shift of fluorescence in polar solvents is accompanied by a marked decrease in emission yield and lifetime for coumarins in ...

... Other efforts to investigate ways of using Auger electron spectroscopy to enhance knowledge of atomic fluorescence yields were not achieved. ...

... Accession Number : AD0625294. Title : EFFECT OF GAMMA RADIATION ON THE FLUORESCENT YIELD OF RUBY,. Corporate ...

A technique based on planar laser-induced fluorescence of 3-pentanone, for measurements of absolute concentration, temperature and fuel/air equivalence ratios in turbulent, high-pressure combustion systems such as an internal combustion engine is presented. Quasi-simultaneous excitation with 248 nm and 308 nm of 3-pentanone that is used as a ...

Using laser-induced fluorescence (LIF), spatially resolved concentration profiles of formaldehyde (H2CO) were obtained in the preheating zone of atmospheric-pressure premixed CH4/air flames stabilized on the central slot of a multiple-slot burner similar in construction to domestic boilers. The isolated pQ1(6) rotational line (339.23 nm) in the 210410 vibronic combination ...

The photoluminescence quantum yield (?(f)) that presents a direct measure for the efficiency of the conversion of absorbed photons into emitted photons is one of the spectroscopic key parameters of functional fluorophores. It determines the suitability of such materials for applications in, for example, (bio)analysis, biosensing, and fluorescence imaging ...

Correlations between two cellular parameters measured by flow cytometry can be visualized rapidly in contour or isometric data displays. In certain cases, the ratio of two measured parameters has biological meaning and yields the distribution of a new cellular property that cannot be directly measured. In this study, the parameters measured were cell volume and the ...

Two novel colored fluorescent proteins were cloned and biophysically characterized from zooxanthellate corals (Anthozoa). A cyan fluorescent protein derived from the coral Montastrea cavernosa (mcCFP) is a trimeric complex with strong blue-shifted excitation and emission maxima at 432 and 477 nm, respectively. The native complex has a ...

We produced carrier-free, nearly isotopically pure 193Irm from thermal-neutron irradiation of 192Os. From studies of the conversion-electron spectrum, the photon spectrum, and the absolute counting rates, we determined the absolute K, L1, L2, L3, M1, M3, M5, N, and O+P conversion coefficients for the first time. With possibly one exception, these values ...

Temperature dependence (over the range from 5 to 75 degrees C) of the fluorescence quantum yield--the parameter sensitive to the rapid (ns) mobility--has been investigated. For native proteins containing 1--2 fluorescing chromophores this dependence in the non-denaturing temperature range can be described by the equation 1/q = a + b . ...

A series of methyl and/or methoxy substituted 1,3-diphenyl-2-pyrazolines were synthesized for evaluation as solutes in liquid scintillation counting systems. The electronic absorption spectra, absolute fluorescence spectra, fluorescence quantum yield, fluorescence decay times, as well as the ...

Contents: Absolute spectrofluorometry; Absolute quantum efficiencies; Phosphorimetry; Measurements of absolute values in biochemical fluorescence spectroscopy; Newer fluorometric methods for the analysis of biologically important compounds; Inorganic ions...

Elemental concentrations of several inorganic elements were determined on a continuous basis with depth using the Schlumberger gamma-ray spectrometry (GST) log in a Santa Fe Energy Co. well in the Kern Front field, Bakersfield, California, Relative gamma-ray yields of Si, Ca, Fe, S, Cl, H, Ti, Gd + Sm, and K were determined using a weighted least-squares fitting of standard ...

The thin target mode of the FLASH (Fluorescence in Air from Showers) experiment was conducted at SLAC. The aim was to measure the total and spectrally resolved fluorescence yield of charged particles traveling through air to better than 10%. The setup consisted of a 15.24 cm thick gas volume which was viewed by two PMT detectors each ...

We demonstrate direct measurements of the absolute molecular two-photon absorption (TPA) cross-sections using a fluorescence technique. A theoretical model of the detected fluorescence signal generated by a femtosecond laser pulse was developed. It is shown that the onset of excited-state saturation depends on the TPA cross-section and ...

BackgroundBased upon defining a common reference point, current real-time quantitative PCR technologies compare relative differences in amplification profile position. As such, absolute quantification requires construction of target-specific standard curves that are highly resource intensive and prone to introducing quantitative errors. Sigmoidal modeling using nonlinear ...

The absolute rate coefficients and product yields for reactions of O(1D) with HCl(1) and HBr(2) at 287 K are presently determined by means of the time-resolved resonance fluorescence detection of O(3P) and H(2S) in conjunction with pulsed laser photolysis of O3/HX/He mixtures. Total rate coefficients for O(1D) removal are found to be, ...

The reactions of ozone with alkenes are an important source of hydroxyl (OH) radicals; however, quantification of their importance is hindered by uncertainties in the absolute OH yield. Hydroxyl radical yields for the gas-phase ozonolysis of isoprene are determined in this paper by four different methods: (1) The use of cyclohexane as ...

The reactions of ozone with alkenes are an important source of hydroxyl (OH) radicals; however, quantification of their importance is hindered by uncertainties in the absolute OH yield. Hydroxyl radical yields for the gas-phase ozonolysis of isoprene are determined in this paper by four different methods: (1) The use of cyclohexane as ...

Over the past few years, there has been significant research activity devoted to the application of fluorescence spectroscopy to strongly scattering media, where photons propagate diffusely. Much of this activity focused on fluorescence as a source of contrast enhancement in optical tomography. Our efforts have emphasized the quantitative recovery of ...

A linear and nonlinear optical spectroscopic characterization is carried out on three azo dyes (Reactive orange 1, Reactive violet 8, and Acidproof purplish red), and on N-(p-hydroxybenzylidene)-diamino-maleonitrile. Fluorescence quantum distributions, fluorescence quantum yields, and fluorescence lifetimes are ...

Absolute K-shell x-ray cross sections and Auger -electron cross sections are measured for carbon for 0.6 to 2.0 MeV protons incident on CH(,4), n-C(,4)H(,10) (n -Butane), i-C(,4)H(,10) (Isobutane), C(,6)H(,6) (Benzene), C(,2)H(,2) (Acetylene), CO and CO(,2). Carbon K-shell fluorescence yields are calculated from the measurements of ...

Absolutely calibrated measurements of the neutron yield are important for the evaluation of the plasma performance such as the fusion gain Q in DD operating tokamaks. Total neutron yield is measured with (sup 235)U and (sup 238)U fission chambers and (sup...

Absolute measurements have been made of the K X-ray quantum yields resulting from electron bombardment of solid targets, containing the elements beryllium, boron, carbon, oxygen, fluorine and aluminium. Beryllium oxide and lithium fluoride targets were used for the oxygen and fluorine measurements, respectively; targets containing at least 99% of the pure ...

A Monte Carlo computer model for simulation and optimization of fluorescent concentrators is described. The program calculates absolute efficiencies 'ab initio'. The input parameters include solar spectrum, dye absorption and emission spectra, dye quantum yield, dye concentration, collector length and thickness, refractive index, and ...

Dilute mixtures of n-octanal in synthetic air (up to 100 ppm) were photolyzed with fluorescent UV lamps (275-380 nm) at 298 K. The main photooxidation products were 1-hexene, CO, vinyl alcohol, and acetaldehyde. The photolysis rates and the absolute quantum yields were found to be slightly dependent on the total pressure. At 100 Torr, ...

For most of the ultra-high-energy cosmic ray (UHECR) experiments and projects (HiRes, AUGER, TA, JEM-EUSO, TUS, �), the detection technique of extensive air showers is based, at least, on the measurement of the air-fluorescence-induced signal. The knowledge of the fluorescence-light yield (FLY) is of paramount importance for the ...

A procedure is presented to convert the comparison of measured fluorescence signals into a comparison of fluorescence yields (FY). The fluorescence yield, which is a property of a solution or a suspension, is defined as the product of the fluorophore conc...

The suitability of the widely used fluorescence standard, quinine sulfate dissolved in dilute H2SO4, as a fluorescence quantum yield standard has been examined, using samples obtained from several sources. The relative fluorescence quantum yield of quinin...

Fluorescence quantum yields and lifetimes for a series of aminocoumarin laser dyes have been measured. The characteristics red shift of fluorescence in polar solvents is accompanied by a marked decrease in emission yield and lifetime for coumarins in whic...

Values of fluorescence yields for eighteen compounds in solution at 23C are reported and are compared to previous literature values. Modifications of the technique of Weber and Teale for measurement of fluorescence yields are described. Fluorescein in 0.1...

... Title : Laser Fluorescence Studies of Chemiluminescent Chemical Reactions. ... Quantum yields, radiative lifetimes, and collisional rate coefficients ...

... Descriptors : *ARGON, *FLUORESCENCE, *X RAY SPECTRA, ATOMIC STRUCTURE, IRON, MEASUREMENT, PULSE HEIGHT ANALYZERS ...

... FLUORESCENCE, *CHEMICAL REACTIONS, *URETHANES ... TOOLS, CHEMICALS, POLYMERIZATION ... ABSORPTION, YIELD, INTENSITY, AMINES ...

The photoabsorption and fluorescence cross sections of CH4 were measured using synchrotron radiation

Time-of-flight (TOF) measurements, employing high-resolution laser-induced fluorescence spectroscopy (LFS) as a probe, have been used to measure the yield and velocity distribution of Zn atoms ejected from a ZnS single crystal under irradiation by 308n nm photons. By comparison with the known ion sputtering yield for pure zinc, the ...

Time-of-flight (TOF) measurements, employing high-resolution laser-induced fluorescence spectroscopy (LFS) as a probe, have been used to measure the yield and velocity distribution of Zn atoms ejected from a ZnS single crystal under irradiation by 308 nm photons. By comparison with the known ion sputtering yield for pure zinc, the ...

A key step in the photosynthetic reactions in photosystem II of green plants is the transfer of an electron from the singlet-excited chlorophyll molecule called P680 to a nearby pheophytin molecule. The free energy difference of this primary charge separation reaction is determined in isolated photosystem II reaction center complexes as a function of temperature by measuring the ...

We have used nuclear parity-changing collisions to obtain absolute level-to-level rate constants for reactive scattering in a triatomic system with identical nuclei. We have determined rate constants for the system (7)Li(2) (*)(A (1)Sigma(u) (+))(v(i)=2,j(i)=19)+(7)Li-->(7)Li+(7)Li(2) (*)(A (1)Sigma(u) (+))(v(f),j(f)), from laser-induced fluorescence ...

A review of the literature on atoms sputtered in electronically excited states is given together with a discussion of various mechanisms that have been proposed to account for the observations. The major observational features that have emerged from the older studies may be summarized as follows: (1) the kinetic energies of neutral atoms in highly excited electronic states are 1-2 orders of ...

The present invention provides optimized cyan fluorescent protein (oCFP) variants. In particular, the variants exhibit increase quantum yield of fluorescence and a single component fluorescence lifetime.

Fluorescence Yield: corrected for pigment packaging & nonphotochemical-quenching . Fluorescence Yield. (radiative). Dust deposition (mg/m2d) ...

... Title : Fluorescence Lifetime and Quantum Efficiency for 5d Yield 4f Transitions in Eu(2+) Doped Chloride and Fluoride Crystals,. ...

... for viable artificial photosynthesis, photovoltaic devices, or ... C7), the fluorescence quantum yields of PPI ... fluorescence quantum yield of the polymer ...

Average satellite and hypersatellite fluorescence yields for different electron configurations are presented for atomic numbers, Z = 7, 8, 9, 10 and 14.

Research effort was concentrated to employ high resolution lithium drifted germanium detectors in an effort to obtain high precision measurements of atomic fluorescence yields. This portion of the research was accomplished successfully. Other efforts to i...

Absolute exp 239 Pu thermal fission yields are given for the stable and long-lived isotopes of krypton, rubidium, strontium, zirconium, xenon, cesium, barium, cerium, neodymium, and samarium. The principal measurement technique for the fission product iso...

Absolute exp 235 U thermal fission yields are given for the stable and long-lived isotopes of krypton, rubidium, strontium, zirconium, molybdenum, ruthenium, xenon, cesium, barium, lanthanum, cerium, neodymium, and samarium. The principal measurement tech...

Samples of the dipyrromethene BF2 dye PM597 incorporated in copolymers of 3-trimethoxysilylpropyl 2-methylprop-2-enoate (TMSPMA, number of polymerizable CC double bonds: ? = 1) with 2-(2-methylprop-2-enoyloxy)ethyl 2-methylprop-2-enoate (EGDMA, ? = 2), [2-(hydroxymethyl)-3-prop-2-(prop-2-enoyloxymethyl)propyl] prop-2-enoate (PETA, ? = 3), and ...

In this letter, we introduce a combined polarization and fluorescence imaging technique for the measurement of fluorescence yield on the surface of turbid media. We use the cross-polarization method to reject the specular reflection and enhance the diffusive backscattering from the turbid media. It has been found that the ratio image ...

solutions (compact fluorescent) that yields efficiency reduction in the cost of energy can yield a different solution (a ...

... Recall that these fluorescence yields are proportional to the product of the dyes' quantum yield and the excited state population n* excited by the ...

Ll,L?,L?2,4,L?1,3 and L? X-ray production cross-sections and L-subshell fluorescence yields (?1 and ?2) in Th and U have been determined at an incident photon energy of 59.5keV by measuring differential cross-sections with angles changing at intervals of 10� from 40� to 130�. In particular, we have investigated the angular dependence of production ...

The relative intensity of photosensitized phosphorescence of singlet oxygen (1O2) at 1270 nm (L1270) and1O2-induced delayed fluorescence (Ldf) of bacteriopheophytin a (BPh) (770 nm) in air-saturated solutions of BPh in hexafluorobenzene in excitation by 337-nm pulses of a nitrogen laso is investigated. It is established that Ldf?L1270. The ratio of the initial intensity of ...

Fluorescence techniques are known for their high sensitivity and are widely used as analytical tools and detection methods for product and process control, material sciences, environmental and biotechnical analysis, molecular genetics, cell biology, medical diagnostics, and drug screening. For routine measurements by fluorescence techniques the existence ...

... FLUORESCENCE, MEASUREMENT), ELECTRON TRANSITIONS, CINCHONA ALKALOIDS, SULFATES, STANDARDS, PURINES, QUINOLINES. ...

Several existing and planned experiments estimate the energies of ultra-high energy cosmic rays from