22 research outputs found
Commissioning and performance of the CMS silicon strip tracker with cosmic ray muons
This is the Pre-print version of the Article. The official published version of the Paper can be accessed from the link below - Copyright @ 2010 IOPDuring autumn 2008, the Silicon Strip Tracker was operated with the full CMS experiment in a comprehensive test, in the presence of the 3.8 T magnetic field produced by the CMS superconducting solenoid. Cosmic ray muons were detected in the muon chambers and used to trigger the readout of all CMS sub-detectors. About 15 million events with a muon in the tracker were collected. The efficiency of hit and track reconstruction were measured to be higher than 99% and consistent with expectations from Monte Carlo simulation. This article details the commissioning and performance of the Silicon Strip Tracker with cosmic ray muons.This work is supported by FMSR (Austria); FNRS and FWO (Belgium); CNPq, CAPES, FAPERJ,
and FAPESP (Brazil); MES (Bulgaria); CERN; CAS, MoST, and NSFC (China); COLCIENCIAS
(Colombia); MSES (Croatia); RPF (Cyprus); Academy of Sciences and NICPB (Estonia);
Academy of Finland, ME, and HIP (Finland); CEA and CNRS/IN2P3 (France); BMBF, DFG,
and HGF (Germany); GSRT (Greece); OTKA and NKTH (Hungary); DAE and DST (India); IPM (Iran); SFI (Ireland); INFN (Italy); NRF (Korea); LAS (Lithuania); CINVESTAV, CONACYT,
SEP, and UASLP-FAI (Mexico); PAEC (Pakistan); SCSR (Poland); FCT (Portugal); JINR (Armenia, Belarus, Georgia, Ukraine, Uzbekistan); MST and MAE (Russia); MSTDS (Serbia); MICINN and CPAN (Spain); Swiss Funding Agencies (Switzerland); NSC (Taipei); TUBITAK and TAEK (Turkey); STFC (United Kingdom); DOE and NSF (USA)
Exploring antioxidant potential and phenolic compound extraction from Vitis vinifera L. using ultrasound-assisted extraction
The research investigates the extraction of antioxidant phenolic compounds from grape pomace, a wine fermentation byproduct. Ultrasound-assisted extraction (UAE), varying parameters such as solute:solvent ratio, power, and time were utilized. UAE was specifically applied to Vitis vinifera L. using high-intensity ultrasound with ratios of 1:18 and 1:42 g:mL, 250 and 400 W power levels, and extraction times of 15 and 20 minutes. Total phenolic content was quantified via the Folin–Ciocalteau reagent, and total flavonoids were determined using quercetin as a standard. Antioxidant capacity was evaluated through ABTS, FRAP, and DPPH Radical Scavenging Assays, with Trolox equivalent antioxidant capacity (TEAC) for comparison. Results indicated a total phenolic content of 50 to 80 μmol GAE/g d.w., with no significant differences among treatments. Total flavonoid concentration ranged from 2.5 to 4 μmol QE/g d.w. Importantly, the solute:solvent ratio impacted antioxidant capacity, with higher ratios showing increased ABTS radical capacity. Treatment 1, with the highest flavonoid content, exhibited the greatest antioxidant capacity against DPPH radicals. This study underscores the intrinsic correlation between cumulative bioactive compound content and the inherent antioxidant capacity of grape pomace extracts. This highlights the potential application of these extracts as antioxidant reservoirs, poised for integration into functional foods and biomedical nutraceuticals
Antioxidant Effect of Nanoparticles Composed of Zein and Orange (<i>Citrus sinensis</i>) Extract Obtained by Ultrasound-Assisted Extraction
In the present research, an orange extract (OE) was obtained and encapsulated in a zein matrix for its subsequent physicochemical characterization and evaluation of its antioxidant capacity. The OE consists of phenolic compounds and flavonoids extracted from orange peel (Citrus sinensis) by ultrasound-assisted extraction (UAE). The results obtained by dynamic light scattering (DLS) and scanning electron microscopy (SEM) indicated that zein nanoparticles with orange extract (NpZOE) presented a nanometric size and spherical shape, presenting a hydrodynamic diameter of 159.26 ± 5.96 nm. Furthermore, ζ-potential evolution and Fourier transform infrared spectroscopy (FTIR) techniques were used to evaluate the interaction between zein and OE. Regarding antioxidant activity, ABTS and DPPH assays indicated no significant differences at high concentrations of orange peel extract and NpZOE; however, NpZOE was more effective at low concentrations. Although this indicates that ultrasonication as an extraction method effectively obtains the phenolic compounds present in orange peels, the nanoprecipitation method under the conditions used allowed us to obtain particles in the nanometric range with positive ζ-potential. On the other hand, the antioxidant capacity analysis indicated a high antioxidant capacity of both OE and the NpZOE. This study presents the possibility of obtaining orange extracts by ultrasound and coupling them to zein-based nanoparticulate systems to be applied as biomedical materials functionalized with antioxidant substances of pharmaceutical utility
Quorum sensing network in clinical strains of A. baumannii : AidA is a new quorum quenching enzyme
Acinetobacter baumannii is an important pathogen that causes nosocomial infections generally associated with high mortality and morbidity in Intensive Care Units (ICUs). Currently, little is known about the Quorum Sensing (QS)/Quorum Quenching (QQ) systems of this pathogen. We analyzed these mechanisms in seven clinical isolates of A. baumannii. Microarray analysis of one of these clinical isolates, Ab1 (A. baumannii ST-2-clon-2010), previously cultured in the presence of 3-oxo-C12-HSL (a QS signalling molecule) revealed a putative QQ enzyme (α/β hydrolase gene, AidA). This QQ enzyme was present in all nonmotile clinical isolates (67% of which were isolated from the respiratory tract) cultured in nutrient depleted LB medium. Interestingly, this gene was not located in the genome of the only motile clinical strain growing in this medium (A. baumannii strain Ab421-GEIH-2010 [Ab7], isolated from a blood sample). The AidA protein expressed in E. coli showed QQ activity. Finally, we observed downregulation of the AidA protein (QQ system attenuation) in the presence of HO (ROS stress). In conclusion, most of the A. baumannii clinical strains were not surface motile (84%) and were of respiratory origin (67%). Only the pilT gene was involved in surface motility and related to the QS system. Finally, a new QQ enzyme (α/β hydrolase gene, AidA protein) was detected in these strains
The CARMENES search for exoplanets around M dwarfs: First visual-channel radial-velocity measurements and orbital parameter updates of seven M-dwarf planetary systems
The appendix tables are only available at the CDS via anonymous ftp to cdsarc.u-strasbg.fr (130.79.128.5) or via http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/609/A117Context. The main goal of the CARMENES survey is to find Earth-mass planets around nearby M-dwarf stars. Seven M dwarfs included in the CARMENES sample had been observed before with HIRES and HARPS and either were reported to have one short period planetary companion (GJ 15 A, GJ 176, GJ 436, GJ 536 and GJ 1148) or are multiple planetary systems (GJ 581 and GJ 876). Aims. We aim to report new precise optical radial velocity measurements for these planet hosts and test the overall capabilities of CARMENES. Methods. We combined our CARMENES precise Doppler measurements with those available from HIRES and HARPS and derived new orbital parameters for the systems. Bona-fide single planet systems were fitted with a Keplerian model. The multiple planet systems were analyzed using a self-consistent dynamical model and their best fit orbits were tested for long-term stability. Results. We confirm or provide supportive arguments for planets around all the investigated stars except for GJ 15 A, for which we find that the post-discovery HIRES data and our CARMENES data do not show a signal at 11.4 days. Although we cannot confirm the super-Earth planet GJ 15 Ab, we show evidence for a possible long-period (P = 7030 d) Saturn-mass (msini = 51.8M) planet around GJ 15 A. In addition, based on our CARMENES and HIRES data we discover a second planet around GJ 1148, for which we estimate a period P = 532.6 days, eccentricity e = 0.342 and minimum mass msini = 68.1M. Conclusions. The CARMENES optical radial velocities have similar precision and overall scatter when compared to the Doppler measurements conducted with HARPS and HIRES. We conclude that CARMENES is an instrument that is up to the challenge of discovering rocky planets around low-mass stars.© ESO, 2018.CARMENES is an instrument for the Centro Astronomico Hispano-Aleman de Calar Alto (CAHA, Almeria, Spain). CARMENES is funded by the German Max-Planck-Gesellschaft (MPG), the Spanish Consejo Superior de Investigaciones Cientificas (CSIC), the European Union through FEDER/ERF FICTS-2011-02 funds, and the members of the CARMENES Consortium (Max-Planck-Institut fur Astronomie, Instituto de Astrofisica de Andalucia, Landessternwarte Konigstuhl, Institut de Ciencies de l'Espai, Insitut fur Astrophysik Gottingen, Universidad Complutense de Madrid, Thuringer Landessternwarte Tautenburg, Instituto de Astrofisica de Canarias, Hamburger Sternwarte, Centro de Astrobiologia and Centro Astronomico Hispano-Aleman), with additional contributions by the Spanish Ministry of Economy, the German Science Foundation (DFG), the Klaus Tschira Stiftung, the states of Baden-Wurttemberg and Niedersachsen, the DFG Research Unit FOR2544 >Blue Planets around Red Stars>, and by the Junta de Andalucia. This work has made use of data from the European Space Agency (ESA) mission Gaia (https://www.cosmos.esa.int/gaia), processed by the Gaia Data Processing and Analysis Consortium (DPAC, https://www.cosmos.esa.int/web/gaia/dpac/consortium). Funding for the DPAC has been provided by national institutions, in particular the institutions participating in the Gaia Multilateral Agreement. This work used the Systemic Console package (Meschiari et al. 2009) for cross-checking our Keplerian and Dynamical fits and the python package astroML (VanderPlas et al. 2012) for the calculation of the GLS periodogram. The IEEC-CSIC team acknowledges support by the Spanish Ministry of Economy and Competitiveness (MINECO) and the Fondo Europeo de Desarrollo Regional (FEDER) through grant ESP2016-80435-C2-1-R, as well as the support of the Generalitat de Catalunya/CERCA programme. The IAA-CSIC team acknowledges support by the Spanish Ministry of Economy and Competitiveness (MINECO) through grants AYA2014-54348-C03-01 and AYA2016-79425-C3-3-P as well as FEDER funds. The UCM team acknowledges support by the Spanish Ministry of Economy and Competitiveness (MINECO) from projects AYA2015-68012-C2-2-P and AYA2016-79425- C3-1,2,3-P and the Spanish Ministerio de Educacion, Cultura y Deporte, programa de Formacion de Profesorado Universitario, under grant FPU15/01476. T. T. and M.K. thank to Jan Rybizki for the very helpful discussion in the early phases of this work. V.J.S.B. is supported by grant AYA2015-69350-C3-2-P from the Spanish Ministry of Economy and Competiveness (MINECO). J.C.S. acknowledges funding support from Spanish public funds for research under project ESP2015-65712-C5-5-R (MINECO/FEDER), and under Research Fellowship program >Ramon y Cajal> with reference RYC2012-09913 (MINECO/FEDER). The contributions of M.A. were supported by DLR (Deutsches Zentrum fur Luft- und Raumfahrt) through the grants 50OW0204 and 50OO1501. J.L.-S. acknowledges the Office of Naval Research Global (award No. N62909-15- 1-2011) for support. C.d.B. acknowledges that this work has been supported by Mexican CONACyT research grant CB-2012-183007 and the Spanish Ministry of Economy and Competitivity through projects AYA2014-54348-C3-2-R. J.I.G.H., and R.R. acknowledge financial support from the Spanish Ministry project MINECO AYA2014-56359-P. J.I.G.H. also acknowledges financial support from the Spanish MINECO under the 2013 Ramon y Cajal program MINECO RYC-2013-14875. V. Wolthoff acknowledges funding from the DFG Research Unit FOR2544 >Blue Planets around Red Stars>, project No. RE 2694/4-1.We thank the anonymous referee for the excellent comments that helped to improve the quality of this paper
The CARMENES search for exoplanets around M dwarfs: High-resolution optical and near-infrared spectroscopy of 324 survey stars
The CARMENES radial velocity (RV) survey is observing 324 M dwarfs to search for any orbiting planets. In this paper, we present the survey sample by publishing one CARMENES spectrum for each M dwarf. These spectra cover the wavelength range 520¿1710 nm at a resolution of at least R >80 000, and we measure its RV, H¿ emission, and projected rotation velocity. We present an atlas of high-resolution M-dwarf spectra and compare the spectra to atmospheric models. To quantify the RV precision that can be achieved in low-mass stars over the CARMENES wavelength range, we analyze our empirical information on the RV precision from more than 6500 observations. We compare our high-resolution M-dwarf spectra to atmospheric models where we determine the spectroscopic RV information content, Q, and signal-to-noise ratio. We find that for all M-type dwarfs, the highest RV precision can be reached in the wavelength range 700¿900 nm. Observations at longer wavelengths are equally precise only at the very latest spectral types (M8 and M9). We demonstrate that in this spectroscopic range, the large amount of absorption features compensates for the intrinsic faintness of an M7 star. To reach an RV precision of 1 m s¿1 in very low mass M dwarfs at longer wavelengths likely requires the use of a 10 m class telescope. For spectral types M6 and earlier, the combination of a red visual and a near-infrared spectrograph is ideal to search for low-mass planets and to distinguish between planets and stellar variability. At a 4 m class telescope, an instrument like CARMENES has the potential to push the RV precision well below the typical jitter level of 3-4 m s-1. © ESO 2018.We thank an anonymous referee for prompt attention and helpful comments that helped to improve the quality of this paper. CARMENES is an instrument for the Centro Astronomico Hispano-Aleman de Calar Alto (CAHA, Almeria, Spain). CARMENES is funded by the German Max-Planck-Gesellschaft (MPG), the Spanish Consejo Superior de Investigaciones Cientificas (CSIC), the European Union through FEDER/ERF FICTS-2011-02 funds, and the members of the CARMENES Consortium (Max-Planck-Institut fur Astronomie, Instituto de Astrofisica de Andalucia, Landessternwarte Konigstuhl, Institut de Ciencies de l'Espai, Insitut fur Astrophysik Gottingen, Universidad Complutense de Madrid, Thuringer Landessternwarte Tautenburg, Instituto de Astrofisica de Canarias, Hamburger Sternwarte, Centro de Astrobiologia and Centro Astronomico Hispano-Aleman), with additional contributions by the Spanish Ministry of Economy, the German Science Foundation through the Major Research Instrumentation Programme and DFG Research Unit FOR2544 >Blue Planets around Red Stars>, the Klaus Tschira Stiftung, the states of Baden-Wurttemberg and Niedersachsen, and by the Junta de Andalucia. This work has made use of the VALD database, operated at Uppsala University, the Institute of Astronomy RAS in Moscow, and the University of Vienna. We acknowledge the following funding programs: European Research Council (ERC-279347), Deutsche Forschungsgemeinschaft (RE 1664/12-1, RE 2694/4-1), Bundesministerium fur Bildung und Forschung (BMBF-05A14MG3, BMBF-05A17MG3), Spanish Ministry of Economy and Competitiveness (MINECO, grants AYA2015-68012-C2-2-P, AYA2016-79425-C3-1,2,3-P, AYA2015-69350-C3-2-P, AYA2014-54348-C03-01, AYA2014-56359-P, AYA2014-54348-C3-2R, AYA2016-79425-C3-3-P and 2013 Ramon y Cajal program RYC-2013-14875), Fondo Europeo de Desarrollo Regional (FEDER, grant ESP2016-80435-C2-1-R, ESP2015-65712-C5-5-R), Generalitat de Catalunya/CERCA programme, Spanish Ministerio de Educacion, Cultura y Deporte, programa de Formacion de Profesorado Universitario (grant FPU15/01476), Deutsches Zentrum fur Luft- und Raumfahrt (grants 50OW0204 and 50OO1501), Office of Naval Research Global (award no. N62909-15-1-2011), Mexican CONACyT grant CB-2012-183007
Alignment of the CMS Muon System with Cosmic-Ray and Beam-Halo Muons
Abstract The CMS muon system has been aligned using cosmic-ray muons collected in 2008 and beam-halo muons from the 2008 LHC circulating beam tests. After alignment, the resolution of the most sensitive coordinate is 80 microns for the relative positions of superlayers in the same barrel chamber and 270 microns for the relative positions of endcap chambers in the same ring structure. The resolution on the position of the central barrel chambers relative to the tracker is comprised between two extreme estimates, 200 and 700 microns, provided by two complementary studies. With minor modifications, the alignment procedures can be applied using muons from LHC collisions, leading to additional significant improvements. * See Appendix A for the list of collaboration members arXiv:0911.4022v2 [physics.ins-det] 8 Feb 2010 FERMILAB-PUB-10-163-CMS Introduction The primary goal of the Compact Muon Solenoid (CMS) experiment [1] is to explore particle physics at the TeV energy scale exploiting the proton-proton collisions delivered by the Large Hadron Collider (LHC) The muon system consists of hundreds of independent tracking chambers mounted within the CMS magnetic field return yoke. Three technologies are employed: Drift Tube (DT) chambers on the five modular wheels of the barrel section, Cathode Strip Chambers (CSC) on the six endcap disks (illustrated in Figs. 1 and 2) and Resistive Plate Chambers (RPC) throughout. The DTs and CSCs are sufficiently precise to contribute to the momentum resolution of highmomentum muons (several hundred GeV/c) assuming that these chambers are well-aligned relative to the CMS tracker, a one-meter radius silicon strip and pixel detector. Between the tracker and the muon system are electromagnetic and hadronic calorimeters (ECAL and HCAL, respectively) for particle identification and energy measurement, as well as the solenoid coil for producing an operating magnetic field strength of 3.8 T in which to measure charged-particle momenta (all shown in The CMS collaboration is developing multiple techniques to align the DT and CSC chambers and their internal layers. Photogrammetry and in-situ measurement devices [3] provide realtime monitoring of potential chamber movements on short timescales and measurements of degrees of freedom to which tracks are only weakly sensitive. Track-based alignment, the subject of this paper, optimizes component positions for a given set of tracks, directly relating the active elements of the detectors traversed by the charged particles in a shared coordinate frame. Methods using tracks are employed both to align nearby components relative to one another and to align all muon chambers relative to the tracker. A challenge to track-based alignment in the CMS muon system is the presence of large quantities of material between the chambers. As a central design feature of the detector, 20-60 cm layers of steel are sandwiched between the chambers to concentrate the magnetic field and absorb beam-produced hadrons. Consequently, uncertainties in track trajectories become significant as muons propagate through the material, making it necessary to develop alignment procedures that are insensitive to scattering, even though typical deviations in the muon trajectories (3-8 mm) are large compared to the intrinsic spatial resolution (100-300 µm). Two types of approaches are presented in this paper: the relative alignment of nearby structures, which avoids extrapolation of tracks through material but does not relate distant coordinate frames to each other, and the alignment using tracks reconstructed in the tracker, which allows for a more sophisticated treatment of propagation effects by simplifying the interdependence of alignment parameters. This paper begins with a brief overview of the geometry of the muon system and conventions to be used thereafter (Section 2), followed by presentations of three alignment procedures: (a) internal alignment of layers within DT chambers using a combination of locally fitted track segments and survey measurements (Section 3); (b) alignment of groups of overlapping CSC chambers relative to one another, using only (c) alignment of each chamber relative to the tracker, using the tracks from the tracker, propagated to the muon system with a detailed map of the magnetic field and material distribution of CMS (Section 5). Procedure (c), above, completes the alignment, relating all local coordinate frames to a shared frame. Its performance is greatly improved by supplying internally aligned chambers from procedure (a), such that only rigid-body transformations of whole chambers need to be considered. Procedures (b) and (c) both align CSC chambers relative to one another, but in different ways: (b) does not need many tracks, only about 1000 per chamber, to achieve high precision, and (c) additionally links the chambers to the tracker. With the first LHC collisions, groups of CSCs will be interaligned using (b) and these rigidbody groups will be aligned relative to the tracker with (c). As more data become available, comparisons of results from (b) and (c) yield highly sensitive tests of systematic errors in (c). Although the ideal tracks for these procedures are muons from LHC collisions, this paper focuses on application of the procedures using currently available data, namely cosmic rays (a and c) and beam-halo muons from circulating LHC beam tests in September 2008 (b). In particular, (c) requires a magnetic field to select high-quality, high-momentum muons and concurrent operation of the tracker and muon systems. The CMS Collaboration conducted a monthlong data-taking exercise known as the Cosmic Run At Four Tesla (CRAFT) during OctoberNovember 2008, with the goal of commissioning the experiment for extended operation The formalism and results of each procedure are presented together. Details of the data transfer and the computing model which were used to implement these procedures are described in Ref. Geometry of the Muon System and Definitions Muon chambers are independent, modular track detectors, each containing 6-12 measurement layers, sufficient to determine the position and direction of a passing muon from the intersections of its trajectory with the layer planes ("hits"). The DT layers are oriented nearly perpendicular to lines radially projected from the beamline, and CSC layers are perpendicular to lines parallel with the beamline. Hits are initially expressed in a local coordinate frame (x, y, z) defined by the layers: z = 0 is the plane of the layer and x is the more precisely measured (or the only measured) of the two plane coordinates. On CSC layers, the most precise measurement is given by cathode strips, which fan radially from the beamline A semi-local coordinate system for the entire chamber is defined with x, y, and z axes nominally parallel to the layers' axes, but with a single origin. Within this common frame, the positions of hits from different layers can be related to each other and combined by a linear fit into segments with position (x,ȳ) and direction ( dx dz , dy dz ). The nominal x direction of every chamber is perpendicular to the beamline and radial projections from the beamline
Identification and Filtering of Uncharacteristic Noise in the CMS Hadron Calorimeter
Commissioning studies of the CMS hadron calorimeter have identified sporadic uncharacteristic noise and a small number of malfunctioning calorimeter channels. Algorithms have been developed to identify and address these problems in the data. The methods have been tested on cosmic ray muon data, calorimeter noise data, and single beam data collected with CMS in 2008. The noise rejection algorithms can be applied to LHC collision data at the trigger level or in the offline analysis. The application of the algorithms at the trigger level is shown to remove 90% of noise events with fake missing transverse energy above 100 GeV, which is sufficient for the CMS physics trigger operation