Resolution of multicomponent fluorescence spectra by an emission wavelength-decay time data matrix

1981 ◽  
Vol 53 (2) ◽  
pp. 272-276 ◽  
Author(s):  
F. J. Knorr ◽  
J. M. Harris
Keyword(s):  
Decay Time ◽  
Fluorescence Spectra ◽  
Emission Wavelength ◽  
Data Matrix ◽  
Time Data

Lumbar Posture during Work among Nurses and Office Workers and the Relation to Back Problems: Statistical Analysis of Angle-vs-Time Data

2000 ◽  
Vol 44 (30) ◽  
pp. 5-465-5-468
Author(s):  
Jeroen P Jansen ◽  
Alex Burdorf ◽  
Allard J van der Beek
Keyword(s):  
Sagittal Plane ◽  
Working Time ◽  
Office Workers ◽  
Data Matrix ◽  
Exposure Level ◽  
Trunk Flexion ◽  
Time Data ◽  
Exposure Patterns ◽  
Exposure Pattern ◽  
Back Problems

Objectives. Electrogoniometers are used to collect continuous information on postural distributions among workers. Enormous quantities of data are generated that have to be reduced to meaningful parameters: angle, duration and frequency. This study 1) shows the patterns of lumbar movements among nurses and office workers; and 2) investigates whether the patterns are associated with back problems. Methods. A direct registration of the lumbar posture in the sagittal plane was made during a working day with an inclinometer. An exposure variation analysis (Mathiassen and Winkel, 1991) was used to summarize information on angle, duration and percentage of working time in a data matrix. A statistical model which takes exposure level, duration, and frequency into account simultaneously was used to analyze these data matrixes and compare exposure patterns between nurses and office workers and between workers with back problems and those without. Results. Nurses spent a higher percentage of their working time in lumbar postures with angles between 40–70 degrees (p<0.03) than office workers. The percentage of the working time spent in a given lumbar posture for periods of 5 seconds or more is less among nurses than among office workers (p<0.01). Among both nurses and office workers, subjects with back problems in the previous 12 months spent less working time in postures sustained for 10 seconds or more in comparison with those without back problems. Conclusion. The exposure patterns of lumbar posture of nurses and office workers discriminated best for working time in trunk flexion over 40 degrees. This implies that observations of flexion at 20 degrees were irrelevant. Furthermore, nurses show a more dynamic exposure pattern than office workers. The findings with respect to back problems indicate that back problems may interfere with posture during work.

Dipole Moments, Polarizabilities and the Fluorescence Behaviour of 4-(9-anthryl)-N,N-dimethylaniline

1979 ◽  
Vol 34 (9) ◽  
pp. 1070-1082 ◽  
Author(s):  
Wolfram Baumann ◽  
F. Petzke ◽  
K.-D. Loosen
Keyword(s):  
Electric Field ◽  
External Electric Field ◽  
Decay Time ◽  
Fluorescence Spectra ◽  
Dipole Moments ◽  
Absorption And Fluorescence Spectra ◽  
Dependent Effect ◽  
Reaction Field ◽  
Solvent Dependence

Abstract It is shown that the solvent dependence of the fluorescence wavenumber and decay time as well as the solvent dependent effect of an external electric field on the absorption and fluorescence spectra of 4-(9-anthryl)-N,N-dimethylaniline can be fully understood taking into account reaction field induced polarizability effects.

Energieübertragung in Anthracen dotierten 2,3 Dimethyl- naphthalin-Einkristallen im Temperaturbereich 4K < T < 300 K / Energy Transfer in Anthracene Doped 2,3 Dimethylnaphthalene Single Crystals

1975 ◽  
Vol 30 (11) ◽  
pp. 1462-1469 ◽  
Author(s):  
P. Ganz
Keyword(s):  
Energy Transfer ◽  
Quantum Yield ◽  
Single Crystals ◽  
Decay Time ◽  
Fluorescence Spectra ◽  
Theoretical Interpretation ◽  
Impurity Molecule ◽  
Relative Quantum Yield ◽  
Light Pulses ◽  
Relative Quantum

The fluorescence spectra and the decay time of emission bands of pure and anthracene doped 2,3 Dimethylnaphthalin single crystals excited by short light pulses were examined for temperatures of 4 to 300 K.On raising the temperature from 40 to 120 K the decay time and the relative quantum yield of 2,3 DN decreases, the emission is shifted by about 150 cm-1 to higher energies and simultanously the energy transfer to the anthracene impurity molecule increases.A model calculation is presented which allows a theoretical interpretation of the experimental results

scholarly journals Frequency domain fluorescence microspectrometry: Application to cellular uptake and drug distribution

2010 ◽  
Vol 24 (3-4) ◽  
pp. 303-307 ◽  
Author(s):  
Petr Praus ◽  
Eva Kocišová ◽  
Peter Mojzeš ◽  
Josef Štepánek ◽  
Franck Sureau ◽  
...  
Keyword(s):  
Cellular Uptake ◽  
Decay Time ◽  
Spectral Region ◽  
High Frequency ◽  
Antisense Oligonucleotide ◽  
Drug Distribution ◽  
Image Intensifier ◽  
Living Cells ◽  
Time Data ◽  
Time Resolved

Time-resolved confocal microspectrofluorometry and fluorescence microimaging were used to monitor how the model antisense oligonucleotide is transported into 3T3 living cells and distributed inside them. Phosphorothioate analog of 15-mer oligothymidylate labeled by ATTO 425 was complexed with Zn(II) 5,10,15,20-tetrakis(4-N-methylpyridyl) porphyrin as an uptake-mediating agent. Homodyne phase-resolved technique based on a high frequency analog modulation of both exciting diode laser and detector image intensifier was used for time-resolved measurements. Decay-time data obtained within a broad range spectral region have provided unique information about the fate of both fluorophores inside the cell.

Synthesis and fluorescence of pyrazolines substituted with pyrimidine and ferrocene subunits

2016 ◽  
Vol 22 (1) ◽  
pp. 31-35
Author(s):  
Manman Liu ◽  
Jian Zhang
Keyword(s):  
Organic Solvents ◽  
Elemental Analysis ◽  
Fluorescence Spectra ◽  
Solvent Polarity ◽  
Emission Wavelength ◽  
H Nmr ◽  
C Nmr

Abstract1,3,5-Trisubstituted 2-pyrazolines were synthesized by the reaction of chalcones with hydrazine in hot ethanol. Their structures were elucidated by 1H NMR, 13C NMR, IR, MS and elemental analysis. The fluorescence spectra were measured in different organic solvents. The emission wavelength is blue shifted with the increase in solvent polarity.

Die Reabsorption in Anthracenkristallen im Temperaturbereich 4 < T < 300 K

1978 ◽  
Vol 33 (6) ◽  
pp. 672-683
Author(s):  
S. Ganz
Keyword(s):  
Experimental Data ◽  
Monte Carlo ◽  
Computer Program ◽  
Decay Time ◽  
Fluorescence Spectra ◽  
Wave Length ◽  
Monte Carlo Techniques

Abstract Fluorescence spectra and decay curves of pure anthracene crystals in dependence of the emission wave length have been investigated using different exciting frequencies. A computer program using Monte Carlo Techniques is described which simulates absorption, emission, reflection and reabsorption of photons in a crystal. This program allows the calculation of fluorescence spectra and decay curves. By comparing the results of this program with experimental data, it is possible to correct the decay time for reabsorption and to calculate the reabsorption coefficient in dependence of temperature.

Raman And Fluorescence Spectra Observed in Laser Microprobe Measurements of Several Compositions in the Ln-Ba-Cu-O System

1990 ◽  
Vol 48 (2) ◽  
pp. 278-279
Author(s):  
Edgar S. Etz ◽  
Thomas D. Schroeder ◽  
Winnie Wong-Ng
Keyword(s):  
Fluorescence Spectra ◽  
Single Phase ◽  
X Ray Diffraction ◽  
Ceramic Powders ◽  
Conventional Solid State Reaction ◽  
X Ray ◽  
Raman Microprobe ◽  
Methods Of Synthesis ◽  
Compositional Homogeneity ◽  
Processing Techniques

We are investigating by Raman microprobe measurements the superconducting and related phases in the LnBa2Cu3O7-x (for x=0 to 1) system where yttrium has been replaced by several of the lanthanide (Ln = Nd,Sm,Eu,Ho,Er) elements. The aim is to relate the observed optical spectra (Raman and fluorescence) to the compositional and structural properties of these solids as part of comprehensive materials characterization. The results are correlated with the methods of synthesis, the processing techniques of these materials, and their superconducting properties. Of relevance is the substitutional chemistry of these isostructural systems, the differences in the spectra, and their microanalytical usefulness for the detection of impurity phases, and the assessment of compositional homogeneity. The Raman spectra of most of these compounds are well understood from accounts in the literature.The materials examined here are mostly ceramic powders prepared by conventional solid state reaction techniques. The bulk samples are of nominally single-phase composition as determined by x-ray diffraction.

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