scholarly journals Unusual Fluorescence Behavior of Pyrene-Amine Containing Dendrimers

Molecules ◽  
2019 ◽  
Vol 24 (22) ◽  
pp. 4083
Author(s):  
Andrea Ruiu ◽  
Mireille Vonlanthen ◽  
Sandra M. Rojas-Montoya ◽  
Israel González-Méndez ◽  
Ernesto Rivera
Keyword(s):  
Tertiary Amine ◽  
Fluorescence Spectra ◽  
Single Photon ◽  
Photon Counting ◽  
Dmso Solution ◽  
Single Photon Counting ◽  
New Class ◽  
Steady State Fluorescence ◽  
The Core ◽  
Photophysical Behavior

A new class of pyrene-based dendrimers, characterized by the presence of a 1,4,7,10-Tetraazacyclododecane (cyclen) unit as the core, was studied by SSF (steady-state fluorescence) and SPC (single-photon counting fluorescence). The photophysical behavior of these dendrimers was studied in THF, DMF and DMSO solution. The typical signals for pyrene-labeled molecules were recorded in each solvent, showing the representative fluorescence spectra: the corresponding emissions of monomer and excimer of the pyrene chromophore are observed. Unexpectedly, the typical quenching of tertiary amine on the pyrene emission was not observed in these dendrimers. Quenching studies were performed by adding up to 3 equivalents of trifluoroacetic acid (TFA). To our knowledge, this is the first report of pyrene’s unquenching behavior by a tertiary amine.

128-Channel Silicon Strip Detector Installed at a Powder Diffractometer

2004 ◽  
Vol 443-444 ◽  
pp. 175-180 ◽  
Author(s):  
A. Zięba ◽  
W. Dąbrowski ◽  
P. Gryboś ◽  
W. Pawroźnik ◽  
J.R. Słowik ◽  
...  
Keyword(s):  
Single Photon ◽  
Photon Counting ◽  
Background Level ◽  
Standard Samples ◽  
Single Photon Counting ◽  
Complex Samples ◽  
New Class ◽  
Strip Detectors ◽  
Diffraction Geometry ◽  
Silicon Strip Detectors

Silicon strip detectors represent a new class of one-dimensional position-sensitive single photon counting devices. They allow a reduction of measurement time at the powder diffractometers by a factor up to 100 compared to instruments with a single counter, while maintaining comparable count statistics. Present work describes a 128-channel detector working with a standard diffractometer. The detector is 12.8 mm long and covers the angular range of 3.2 deg. We discuss the diffraction geometry in real and reciprocal space, the FWHM of diffraction peaks, and the background level. Measurements were made on standard samples and on complex samples of industrial importance (e. g., portland clinker). Applications of the detector to diffraction measurements of single crystals and thin films are discussed briefly.

Single Point PICA Probing with an Avalanche Photo-Diode

2001 ◽  
Author(s):  
Mike Bruce ◽  
Rama R. Goruganthu ◽  
Shawn McBride ◽  
David Bethke ◽  
J.M. Chin
Keyword(s):  
Single Photon ◽  
Single Point ◽  
Photon Counting ◽  
Ring Oscillator ◽  
Time Resolved ◽  
Single Photon Counting ◽  
Photo Diode ◽  
Avalanche Photo Diode ◽  
Photo Multiplier Tube ◽  
Channel Plate

Abstract For time resolved hot carrier emission from the backside, an alternate approach is demonstrated termed single point PICA. The single point approach records time resolved emission from an individual transistor using time-correlated-single-photon counting and an avalanche photo-diode. The avalanche photo-diode has a much higher quantum efficiency than micro-channel plate photo-multiplier tube based imaging cameras typically used in earlier approaches. The basic system is described and demonstrated from the backside on a ring oscillator circuit.

scholarly journals UVscope and its application aboard the ASTRI-Horn telescope

2021 ◽  
Author(s):  
Maria Concetta Maccarone ◽  
Giovanni La Rosa ◽  
Osvaldo Catalano ◽  
Salvo Giarrusso ◽  
Alberto Segreto ◽  
...  
Keyword(s):  
Gamma Ray ◽  
Single Photon ◽  
Photon Counting ◽  
Light Flux ◽  
Cosmic Ray ◽  
High Energy ◽  
Wide Field ◽  
High Energy Astrophysics ◽  
Single Photon Counting ◽  
Photon Counting Mode

AbstractUVscope is an instrument, based on a multi-pixel photon detector, developed to support experimental activities for high-energy astrophysics and cosmic ray research. The instrument, working in single photon counting mode, is designed to directly measure light flux in the wavelengths range 300-650 nm. The instrument can be used in a wide field of applications where the knowledge of the nocturnal environmental luminosity is required. Currently, one UVscope instrument is allocated onto the external structure of the ASTRI-Horn Cherenkov telescope devoted to the gamma-ray astronomy at very high energies. Being co-aligned with the ASTRI-Horn camera axis, UVscope can measure the diffuse emission of the night sky background simultaneously with the ASTRI-Horn camera, without any interference with the main telescope data taking procedures. UVscope is properly calibrated and it is used as an independent reference instrument for test and diagnostic of the novel ASTRI-Horn telescope.

Single Photon Counting Module Based on Large Area APD and Novel Logic Circuit for Quench and Reset Pulse Generation

2007 ◽  
Vol 13 (4) ◽  
pp. 926-933 ◽  
Author(s):  
Vinit H. Dhulla ◽  
Georgiy Gudkov ◽  
Dmitri Gavrilov ◽  
Andrey Stepukhovich ◽  
Andriy Tsupryk ◽  
...  
Keyword(s):  
Single Photon ◽  
Photon Counting ◽  
Logic Circuit ◽  
Pulse Generation ◽  
Large Area ◽  
Single Photon Counting ◽  
Reset Pulse
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