Search results for "Detector"
showing 10 items of 3491 documents
Ligand-Length Modification in CsPbBr3 Perovskite Nanocrystals and Bilayers with PbS Quantum Dots for Improved Photodetection Performance
2020
Nanocrystals surface chemistry engineering offers a direct approach to tune charge carrier dynamics in nanocrystals-based photodetectors. For this purpose, we have investigated the effects of altering the surface chemistry of thin films of CsPbBr3 perovskite nanocrystals produced by the doctor blading technique, via solid state ligand-exchange using 3-mercaptopropionic acid (MPA). The electrical and electro-optical properties of photovoltaic and photoconductor devices were improved after the MPA ligand exchange, mainly because of a mobility increase up to 5 ×
A new ATLAS muon CSC readout system with system on chip technology on ATCA platform
2015
The ATLAS muon Cathode Strip Chamber (CSC) backend readout system has been upgraded during the LHC 2013-2015 shutdown to be able to handle the higher Level-1 trigger rate of 100 kHz and the higher occupancy at Run 2 luminosity. The readout design is based on the Reconfigurable Cluster Element (RCE) concept for high bandwidth generic DAQ implemented on the Advanced Telecommunication Computing Architecture (ATCA) platform. The RCE design is based on the new System on Chip XILINX ZYNQ series with a processor-centric architecture with ARM processor embedded in FPGA fabric and high speed I/O resources together with auxiliary memories to form a versatile DAQ building block that can host applicati…
Real-time data processing in the ALICE High Level Trigger at the LHC
2019
At the Large Hadron Collider at CERN in Geneva, Switzerland, atomic nuclei are collided at ultra-relativistic energies. Many final-state particles are produced in each collision and their properties are measured by the ALICE detector. The detector signals induced by the produced particles are digitized leading to data rates that are in excess of 48 GB/$s$. The ALICE High Level Trigger (HLT) system pioneered the use of FPGA- and GPU-based algorithms to reconstruct charged-particle trajectories and reduce the data size in real time. The results of the reconstruction of the collision events, available online, are used for high level data quality and detector-performance monitoring and real-tim…
A comparative study of the behaviour of silver, copper and nickel submitted to a constant high power flux density
2005
In this paper, we present a numerical simulation of three metal cathode (silver, copper and nickel) submitted to a constant flux power flux density ranging between and . The goal is to compare the interface evolution (vaporization and liquefaction rate, appearance time of liquid and vapour, energetic repartition) to predict the behaviour of the cathodes during an electric arc.
Analytical study of proteinaceous binding media in works of art by gas chromatography using alkyl chloroformates as derivatising agents.
2001
In this work, we present the results obtained in an analytical study of the different types of proteinaceous binding media most commonly used in paintings, using GC-FID as the technique of analysis and GC-MS as a confirmatory technique. The application of this methodology requires prior hydrolysis of the proteins in the binding media to obtain free amino acids and then volatile derivatives, in this case by reaction with chloroformates due to advantages of speed, safety and the aqueous medium in which the reaction occurs. The method proposed for the proteinaceous binding media study is to calculate the proportions of the different amino acids with respect to alanine. This method provided goo…
Determination of the four major surfactant classes in cleaning products by reversed-phase liquid chromatography using serially connected UV and evapo…
2016
Abstract A method for the simultaneous determination of the most frequently used surfactant families –linear alkyl benzenesulphonates (LAS), alkyl ether sulphates (AES), fatty alcohol ethoxylates (FAE) and oleins (soaps, fatty acid salts) – in cleaning products, has been developed. The common reversed phase octyl (C8), pentafluorophenyl and biphenyl columns were not capable of separating the anionic LAS and AES classes; however, since only LAS absorbs in the UV, these two classes were independently quantified using a C8 column and serially connected UV and ELSD detection. The best compromise to resolve the four surfactant classes and the oligomers within the classes was achieved with a C8 c…
Separation of Proteic Primary Amino Acids under Several Reversed‐Phase Liquid Chromatographic Conditions
2006
Abstract The reversed‐phase liquid chromatographic (RPLC) analysis of proteic primary amino acids with acetonitrile‐water, using pre‐column derivatisation with o‐phthalaldehyde (OPA) and N‐acetylcysteine (NAC), was compared with RPLC modes using trifluoroacetic acid or pentadecafluorooctanoic acid and evaporative light‐scattering detection, or sodium dodecyl sulphate micelles with pre‐ and post‐column derivatisation. The importance of column lifetime, risk of potential damages in the instrumentation, retention and resolution, was considered. Among the assayed approaches, the best is still aqueous‐organic RPLC with pre‐column derivatisation. It not only yields the most reliable results, but …
Photon yields and decay times of cross luminescence in ionic crystals
1992
The authors report on the scintillation properties of the ternary inorganic crystals KMgF/sub 3/, KYF/sub 4/:Rb, K/sub 2/YF/sub 5/, KLuF/sub 4/, RbMgF/sub 3/, KZnF/sub 3/, BaTm/sub 2/F/sub 8/, LiYF/sub 4/:Nd, and BaF/sub 2/:Rb. The scintillation light output of these crystals was estimated from the X-ray-induced emission spectra. Optical absorption spectra and decay time spectra were also measured and are presented. The first four crystals produced cross-luminescence (CL) with a decay time of about 1.5 ns. CL was not observed for the other crystals. >
Relaxation of electron-hole pairs and scintillation mechanism in alkali halide crystals
1997
Abstract The mechanism of the ionizing radiation energy transfer from host lattice to luminescence centers is discussed taking into account the results of the recent experimental investigations of electron-hole pair relaxation in alkali iodide crystals. The high scintillation yield in CsI-Tl, CsI-Na and partially in Nal-Tl crystals is explained by the process of the motion and capture of a one-center self-trapped exciton by impurity ions.
Analysis of odour and taste problems in high-density polyethene
1998
Abstract The compounds that cause off-flavours in plastics, have been recognized mainly as carbonyl compounds (aldehydes, ketones and esters). They occur in low concentrations, and due to their low-threshold odour concentrations, their typical odours were identified. Most of these off-flavour compounds are volatile. Chemical analysis of smelling compounds requires a very sensitive method with a high-resolution capability. The analysis of volatile organic compounds (VOCs) in high density polyethene (HD-PE) granules and waters in which the granules have been shaken for 4 h, were carried out by gas chromatography–mass spectrometry–sniffing system (GC–MS–SNIFF) and by gas chromatography–fourier…