Second-harmonic generation of ZnO nanoparticles synthesized by laser ablation of solids in liquids

We report the synthesis of small zinc oxide nanoparticles (ZnO NPs) based colloidal suspensions and the study of second-harmonic generation from aggregated ZnO NPs deposited on glass substrates. The colloidal suspensions were obtained using the laser ablation of solids in liquids technique, ablating a Zn solid target immersed in acetone as the liquid medium, with ns-laser pulses (1064 nm) of a Nd-YAG laser. The per pulse laser fluence, the laser repetition rate frequency and the ablation time were kept constant. The absorption evolution of the obtained suspensions was optically characterized through absorption spectroscopy until stabilization. Raman spectroscopy, SEM and HRTEM were used to provide evidence of the ZnO NPs structure. HRTEM results showed that 5–8 nm spheroids ZnO NPs were obtained. Strong second-harmonic signal is obtained from random ZnO monocrystalline NPs and from aggregated ZnO NPs, suggesting that the high efficiency of the nonlinear process may not depend on the NPs size or aggregation state

Single source coherent anti-Stokes Raman microspectroscopy using spectral focusing

We demonstrate coherent anti-Stokes Raman scattering (CARS) microspectroscopy using a single Ti:sapphire laser oscillator and simple passive optical elements. Spectral selection by dichroic mirrors and linear chirping by glass elements creates a vibrational excitation tuneable over a large spectral range ( ∼ 800–2200 cm−1) with adjustable spectral resolution ( ∼ 10–100 cm−1). We furthermore demonstrate the applicability of differential CARS, enhancing the chemical selectivity, with the proposed single-laser configuration

Anderson Localization of Thermal Phonons Leads to a Thermal Conductivity Maximum

Our elastic model of ErAs disordered GaAs/AlAs superlattices exhibits a local thermal conductivity maximum as a function of length due to exponentially suppressed Anderson-localized phonons. By analyzing the sample-to-sample fluctuations in the dimensionless conductance, g, the transition from diffusive to localized transport is identified as the crossover from the multichannel to single-channel transport regime g ≈ 1. Single parameter scaling is shown to hold in this crossover regime through the universality of the probability distribution of g that is independent of system size and disorder strength.Solid-State Solar-Thermal Energy Conversion Center (Award DE-FG02-09ER46577

Impact of cooking method on phenolic composition and antioxidant potential of four varieties of Phaseolus vulgaris L. and Glycine max L.

The present study aimed to investigate the effects of different cooking conditions - atmospheric (100°C) and pressure cooking (115°C) - on the phenolic composition and antioxidant activity of methanolic extracts of four Phaseolus vulgaris varieties and soy (Glycine max). Contrary to soy, in P. vulgaris varieties both cooking methods increased drastically the total phenolic, flavonoid, and ortho-diphenol content, as well as antioxidant capacity. These results were corroborated by HPLC analysis, where an overall increase of phenolic acids and flavonoids was detected in processed samples. However, draining the cooking water significantly decreased phenolic acids, flavonoids and antioxidant activity in all P. vulgaris varieties and as well as soy. The hypothesis that cooking increases the compound accessibility and nutritional value through increased release of phytochemicals was verified in the present study for P. vulgaris varieties. Keeping the cooking water is crucial to the increased nutritional value of all Phaseolus varieties. Overall, compared with the tested varieties of Phaseolus, soy, to which many health benefits are attributed, is not the best legume source of antioxidants.The author Catarina I. Teixeira-Guedes acknowledges the financial support provided FCT-Portuguese Foundation for Science and Technology (SFRH/BD/52544/2014), under the Doctoral Program “Agricultural Production Chains – from fork to farm” (PD/00122/ 2012). This work was supported by the European Investment Funds FEDER/COMPETE/POCI– Operational Competitiveness and Internationalization Programme [POCI-01-0145-FEDER-006958] and Portuguese Foundation for Science and Technology (FCT) [UID/AGR/ 04033/2019]; Project I&D Interact - Integrative Research in Environment, Agro-Chain and Technology [NORTE-01-0145-FEDER000017], co-financed by European Regional Development Fund (FEDER) through NORTE 2020 (Programa Operacional Regional do Norte 2014/2020).info:eu-repo/semantics/publishedVersio

Single hadron response measurement and calorimeter jet energy scale uncertainty with the ATLAS detector at the LHC

The uncertainty on the calorimeter energy response to jets of particles is derived for the ATLAS experiment at the Large Hadron Collider (LHC). First, the calorimeter response to single isolated charged hadrons is measured and compared to the Monte Carlo simulation using proton-proton collisions at centre-of-mass energies of sqrt(s) = 900 GeV and 7 TeV collected during 2009 and 2010. Then, using the decay of K_s and Lambda particles, the calorimeter response to specific types of particles (positively and negatively charged pions, protons, and anti-protons) is measured and compared to the Monte Carlo predictions. Finally, the jet energy scale uncertainty is determined by propagating the response uncertainty for single charged and neutral particles to jets. The response uncertainty is 2-5% for central isolated hadrons and 1-3% for the final calorimeter jet energy scale.Comment: 24 pages plus author list (36 pages total), 23 figures, 1 table, submitted to European Physical Journal

Standalone vertex finding in the ATLAS muon spectrometer

A dedicated reconstruction algorithm to find decay vertices in the ATLAS muon spectrometer is presented. The algorithm searches the region just upstream of or inside the muon spectrometer volume for multi-particle vertices that originate from the decay of particles with long decay paths. The performance of the algorithm is evaluated using both a sample of simulated Higgs boson events, in which the Higgs boson decays to long-lived neutral particles that in turn decay to bbar b final states, and pp collision data at √s = 7 TeV collected with the ATLAS detector at the LHC during 2011

Measurements of Higgs boson production and couplings in diboson final states with the ATLAS detector at the LHC

Measurements are presented of production properties and couplings of the recently discovered Higgs boson using the decays into boson pairs, H →γ γ, H → Z Z∗ →4l and H →W W∗ →lνlν. The results are based on the complete pp collision data sample recorded by the ATLAS experiment at the CERN Large Hadron Collider at centre-of-mass energies of √s = 7 TeV and √s = 8 TeV, corresponding to an integrated luminosity of about 25 fb−1. Evidence for Higgs boson production through vector-boson fusion is reported. Results of combined fits probing Higgs boson couplings to fermions and bosons, as well as anomalous contributions to loop-induced production and decay modes, are presented. All measurements are consistent with expectations for the Standard Model Higgs boson

Measurement of the top quark-pair production cross section with ATLAS in pp collisions at \sqrt{s}=7\TeV

A measurement of the production cross-section for top quark pairs(\ttbar) in $pp$ collisions at \sqrt{s}=7 \TeV is presented using data recorded with the ATLAS detector at the Large Hadron Collider. Events are selected in two different topologies: single lepton (electron $e$ or muon $\mu$) with large missing transverse energy and at least four jets, and dilepton ($ee$, $\mu\mu$ or $e\mu$) with large missing transverse energy and at least two jets. In a data sample of 2.9 pb-1, 37 candidate events are observed in the single-lepton topology and 9 events in the dilepton topology. The corresponding expected backgrounds from non-\ttbar Standard Model processes are estimated using data-driven methods and determined to be $12.2 \pm 3.9$ events and $2.5 \pm 0.6$ events, respectively. The kinematic properties of the selected events are consistent with SM \ttbar production. The inclusive top quark pair production cross-section is measured to be \sigmattbar=145 \pm 31 ^{+42}_{-27} pb where the first uncertainty is statistical and the second systematic. The measurement agrees with perturbative QCD calculations.Comment: 30 pages plus author list (50 pages total), 9 figures, 11 tables, CERN-PH number and final journal adde

Measurement of the top quark pair cross section with ATLAS in pp collisions at √s=7 TeV using final states with an electron or a muon and a hadronically decaying τ lepton

A measurement of the cross section of top quark pair production in proton-proton collisions recorded with the ATLAS detector at the Large Hadron Collider at a centre-of-mass energy of 7 TeV is reported. The data sample used corresponds to an integrated luminosity of 2.05 fb -1. Events with an isolated electron or muon and a τ lepton decaying hadronically are used. In addition, a large missing transverse momentum and two or more energetic jets are required. At least one of the jets must be identified as originating from a b quark. The measured cross section, σtt-=186±13(stat.)±20(syst.)±7(lumi.) pb, is in good agreement with the Standard Model prediction