Search results for "sensitive"

Technology of p-type microstrip detectors with radiation hard p-spray, p-stop and moderated p-spray insulations

2007

5 pages, 8 figures.-- PACS nrs.: 29.40.Gx; 29.40.-- ISI Article Identifier: 000249604700010.

Action potentials induce biomagnetic fields in Venus flytrap plants

2020

Upon stimulation, plants elicit electrical signals that can travel within a cellular network analogous to the animal nervous system. It is well-known that in the human brain, voltage changes in certain regions result from concerted electrical activity which, in the form of action potentials (APs), travels within nerve-cell arrays. Electrophysiological techniques like electroencephalography, magnetoencephalography, and magnetic resonance imaging are used to record this activity and to diagnose disorders. In the plant kingdom, two types of electrical signals are observed: all-or-nothing APs of similar amplitudes to those seen in humans and animals, and slow-wave potentials of smaller amplitud…

First coincidences in pre-clinical Compton camera prototype for medical imaging

2003

Abstract Compton collimated imaging may improve the detection of gamma rays emitted by radioisotopes used in single photon emission computed tomography (SPECT). We present a crude prototype consisting of a single 500 μm thick, 256 pad silicon detector with pad size of 1.4×1.4 mm 2 , combined with a 15×15×1 cm 3 NaI scintillator crystal coupled to a set of 20 photo multipliers. Emphasis is placed on the performance of the silicon detector and the associated read-out electronics, which has so far proved to be the most challenging part of the set-up. Results were obtained using the VATAGP3, 128 channel low-noise self-triggering ASIC as the silicon detector's front-end. The noise distribution (…

Polarization-sensitive population trapping in an optically pumped laser

1994

Synthesis and characterization of redox-sensitive polyurethanes based on L-glutathione oxidized and poly(ether ester) triblock copolymers

2021

Abstract Segmented polyurethanes, based on PCL-PEG-PCL copolymers, 1,4-diisocyanatobutane and l -glutathione oxidized, used as chain extender, were synthetized. Three different reactions conditions were investigated using three different copolymers having ɛ-CL/polyethylene glycol molar ratios equal to 12, 24 and 36 and three different reaction conditions. As investigated by size exclusion chromatography analyses and quantification of l -glutathione, the polymerization and the extension phase's efficiency depended on the ɛ-CL/PEG ratio and the extension phase's operating temperature. Three selected polyurethanes were characterized by spectroscopic, differential scanning calorimetry (DSC) and…

Molecular Engineering of Porphyrin‐Tapes/Phthalocyanine Heterojunctions for a Highly Sensitive Ammonia Sensor

2020

International audience; Modulating the interfacial charge alignments by molecular engineering in an organic heterojunction device is a smart strategy to improve its conductivity, which can be exploited in high performance gas sensors development. Herein, the fabrication of new organic heterojunction devices based on porphyrin tapes and phthalocyanines and their potentiality in ammonia sensing at different relative humidity (rh) are investigated. The devices are built using dry approach relying on oxidative chemical vapor deposition for simultaneous synthesis, doping and deposition of the porphyrin tape layer and physical vapor deposition of phthalocyanine layer. The association of the porph…

A large-area scintillating fibre detector for relativistic heavy ions

1998

Abstract A scintillating fibre detector for relativistic heavy ions with an active area of 50 × 50 cm 2 has been developed and was tested with various ion beams (1 ≤ Z ≤ 92). At count rates of up to 10 5 particles/s, the position resolution was found to be determined by the fibre width of 1 mm; depending on the nuclear charge of the beam, efficiencies between 89% and 100% and time resolutions between 800 and 200 ps (FWHM) were obtained.

Analytical techniques for the determination of bismuth in solid environmental samples

2006

Abstract Bismuth is a trace element of the Earth’s crust, which is becoming environmentally significant. Although bismuth has relatively low toxicity, it can form characteristic intracytoplasmatic inclusions. This article illustrates the increasing need for fast pre-treatment techniques and highly sensitive detection methods for accurate measurements of bismuth at extremely low concentrations in solid environmental matrices.

Planar Bragg Grating Sensor for the Detection of CFC-11

2018

We demonstrate the fabrication of a highly sensitive opto-chemical sensor system based on cyclodextrin derivative functionalized planar Bragg gratings for an online in-situ detection and measurement of the environmentally harmful propellant trichlorofluoromethane in real-time.

Photomagnetism of Molecular Systems

2001

This article reviews various classes of transition metal compounds which display in the solid state light sensitive electronic structure modifications accompanied by drastic changes of their magnetic and/or optical properties, i.e., photomagnetism. Selected examples from this rapidly expanding field, include spin crossover, stilbenoid and nitrosyl complexes, as well as Prussian blue analogues.