Search results for "Solid"
showing 10 items of 3575 documents
A study of the material in the ATLAS inner detector using secondary hadronic interactions
2011
The ATLAS inner detector is used to reconstruct secondary vertices due to hadronic interactions of primary collision products, so probing the location and amount of material in the inner region of ATLAS. Data collected in 7 TeV pp collisions at the LHC, with a minimum bias trigger, are used for comparisons with simulated events. The reconstructed secondary vertices have spatial resolutions ranging from ~ 200μm to 1 mm. The overall material description in the simulation is validated to within an experimental uncertainty of about 7%. This will lead to a better understanding of the reconstruction of various objects such as tracks, leptons, jets, and missing transverse momentum.
Concentration depending fluorescence of 8-(di-(2-picolyl)) aminoBODIPY in solution
2014
[EN] An 8-dipicolylBODIPY derivative has been prepared and its photophysical properties evaluated under different conditions. Two different structures, hemicyanine and cyanine, are observed (depending on the solvent or the solution concentration). The hemicyanine form is not emissive whereas the cyanine form is fluorescent. This behavior is related with the planarity degree of the BODIPY core. The X-ray structure of the compound is reported and it shows that in solid state the hemicyanine form is present. The hemicyanine form seems to be stabilized by aggregation and is the main compound in concentrated solutions whereas the cyanine form is present in diluted solutions that are photochemica…
Myoglobin embedded in saccharide amorphous matrices: water-dependent domains evidenced by small angle X-ray scattering
2010
We report Small Angle X-ray Scattering (SAXS) measurements performed on samples of carboxy-myoglobin (MbCO) embedded in low-water trehalose glasses. Results showed that, in such samples, "low-protein" trehalose-water domains are present, surrounded by a protein-trehalose-water background; such finding is supported by Infrared Spectroscopy (FTIR) measurements. These domains, which do not appear in the absence of the protein and in analogous sucrose systems, preferentially incorporate the incoming water at the onset of rehydration, and disappear following large hydration. This observation suggests that, in organisms under anhydrobiosis, analogous domains could play a buffering role against th…
Determination of fatty alcohol ethoxylates by derivatisation with maleic anhydride followed by liquid chromatography with UV-vis detection.
2007
The esterification of fatty alcohol ethoxylates (FAEs) by melting with maleic anhydride has been studied in the presence of urea. The reaction rate and yield of non-ethoxylated and ethoxylated alcohols increase largely when grinded urea is suspended in the reaction medium, a 100% yield being achieved at 80 degrees C in 15 min. The procedure is tolerant to the presence of large amounts of water. The UV-vis response factors of the derivatives of individual FAE oligomers vary little with the number of carbon atoms in the alkyl chain, n, and the number of ethylene oxide units, m. Derivatised samples of industrial FAE mixtures, cleaning products and river and sea waters were chromatographed on a…
Design, upgrade and characterization of the silicon photomultiplier front-end for the AMIGA detector at the Pierre Auger Observatory
2021
The successful installation, commissioning, and operation of the Pierre Auger Observatory would not have been possible without the strong commitment and effort from the technical and administrative staff in Malargue. We are very grateful to the following agencies and organizations for financial support: Argentina -Comision Nacional de Energia Atomica; Agencia Nacional de Promocion Cientifica y Tecnologica (ANPCyT); Consejo Nacional de Investigaciones Cientificas y Tecnicas (CONICET); Gobierno de la Provincia de Mendoza; Municipalidad de Malargue; NDM Holdings and Valle Las Lenas; in gratitude for their continuing cooperation over land access; Australia -the Australian Research Council; Braz…
Beam test measurements of Low Gain Avalanche Detector single pads and arrays for the ATLAS High Granularity Timing Detector
2018
For the high luminosity upgrade of the LHC at CERN, ATLAS is considering the addition of a High Granularity Timing Detector (HGTD) in front of the end cap and forward calorimeters at |z|= 3.5 m and covering the region 2.4 <|η|< 4 to help reducing the effect of pile-up. The chosen sensors are arrays of 50 μm thin Low Gain Avalanche Detectors (LGAD). This paper presents results on single LGAD sensors with a surface area of 1.3×1.3 mm2 and arrays with 2×2 pads with a surface area of 2×2 mm2 or 3×3 mm2 each and different implant doses of the p+ multiplication layer. They are obtained from data collected during a beam test campaign in autumn 2016 with a pion beam of 120 GeV energy at the CERN SP…
Mini-MALTA: Radiation hard pixel designs for small-electrode monolithic CMOS sensors for the High Luminosity LHC
2020
Journal of Instrumentation 15(02), P02005 (2020). doi:10.1088/1748-0221/15/02/P02005
Alignment of the ALICE Inner Tracking System with cosmic-ray tracks
2010
ALICE (A Large Ion Collider Experiment) is the LHC (Large Hadron Collider) experiment devoted to investigating the strongly interacting matter created in nucleus-nucleus collisions at the LHC energies. The ALICE ITS, Inner Tracking System, consists of six cylindrical layers of silicon detectors with three different technologies; in the outward direction: two layers of pixel detectors, two layers each of drift, and strip detectors. The number of parameters to be determined in the spatial alignment of the 2198 sensor modules of the ITS is about 13,000. The target alignment precision is well below 10 micron in some cases (pixels). The sources of alignment information include survey measurement…
Tailored pump-probe transient spectroscopy with time-dependent density-functional theory: controlling absorption spectra
2016
Recent advances in laser technology allow us to follow electronic motion at its natural time-scale with ultra-fast time resolution, leading the way towards attosecond physics experiments of extreme precision. In this work, we assess the use of tailored pumps in order to enhance (or reduce) some given features of the probe absorption (for example, absorption in the visible range of otherwise transparent samples). This type of manipulation of the system response could be helpful for its full characterization, since it would allow us to visualize transitions that are dark when using unshaped pulses. In order to investigate these possibilities, we perform first a theoretical analysis of the non…
Spinovo rozlisena time-of-flight k-reozlisena fotoemissia Ir-- Kompletny fotoemissny experiment.
2017
Ultramicroscopy 183, 19 - 29 (2017). doi:10.1016/j.ultramic.2017.06.025