Search results for " SPECT"

The maximum carbonyl ratio (MCR) as a new index for the structural classification of secondary organic aerosol components

2021

RATIONALE Organic aerosols (OA) account for a large fraction of atmospheric fine particulate matter and thus are affecting climate and public health. Elucidation of the chemical composition of OA is the key for addressing the role of ambient fine particles at the atmosphere-biosphere interface and mass spectrometry is the main method to achieve this goal. METHODS High-resolution mass spectrometry (HRMS) is on its way to becoming one of the most prominent analytical techniques, also for the analysis of atmospheric aerosols. The combination of high mass resolution and accurate mass determination allows the elemental compositions of numerous compounds to be easily elucidated. Here a new parame…

Design, characterization, and first field deployment of a novel aircraft-based aerosol mass spectrometer combining the laser ablation and flash vapor…

2021

In this paper, we present the design, development, and characteristics of the novel aerosol mass spectrometer ERICA (ERC Instrument for Chemical composition of Aerosols; ERC – European Research Council) and selected results from the first airborne field deployment. The instrument combines two well-established methods of real-time in situ measurements of fine particle chemical composition. The first method is the laser desorption and ionization technique, or laser ablation technique, for single-particle mass spectrometry (here with a frequency-quadrupled Nd:YAG laser at λ = 266 nm). The second method is a combination of thermal particle desorption, also called flash vaporization, and electro…

Unexpected Behavior of Enaminones: Interesting New Routes to 1,6-Naphthyridines, 2-Oxopyrrolidines and Pyrano[4,3,2-de][1,6]naphthyridines

2012

Reaction of enaminones 1a–d with 2-aminoprop-1-ene-1,1,3-tricarbonitrile (2) in the presence of AcOH/NH4OAc afforded 7-amino-5-oxo-5,6-dihydro-1,6-naphthyridine-8-carbonitrile derivatives 9a–d. On the other hand, 2-aminopyrano[4,3,2-de] [1,6]naphthyridine-3-carbonitriles 20a–c,e were the only obtained products from the reactions of 1a–d with 2 in the presence of AcOH/NaOAc, while 1d afforded [3,5-bis-(4-chloro-benzoyl)-phenyl]-(4-chloro-phenyl)-methanone 21 under the same condition. The reaction of 2 with diethyl acetylenedicarboxylate in the presence of AcOH/NH4OAc afforded (4-cyano-5-dicyanomethylene-2-oxo-2,5-dihydro-1H-pyrrol-3-yl)-acetic acid eth…

Thermomineral waters of Greece: geochemical characterization

2020

Electrical Brain Activity and Its Functional Connectivity in the Physical Execution of Modern Jazz Dance

2020

Besides the pure pleasure of watching a dance performance, dance as a whole-body movement is becoming increasingly popular for health-related interventions. However, the science-based evidence for improvements in health or well-being through dance is still ambiguous and little is known about the underlying neurophysiological mechanisms. This may be partly related to the fact that previous studies mostly examined the neurophysiological effects of imagination and observation of dance rather than the physical execution itself. The objective of this pilot study was to investigate acute effects of a physically executed dance with its different components (recalling the choreography and physical …

Contributions to Phase Two of AGATA electronics

2020

En el campo de la física nuclear, la espectroscopia de rayos gamma de alta resolución es un método preciso para estudiar la estructura del núcleo, extrayendo la energía y la distribución angular de los fotones gamma emitidos en las transiciones entre estados nucleares. Para obtener núcleos en un estado excitado y por tanto emitan rayos gamma, hemos de hacer chocar la materia, produciendo reacciones nucleares (espectroscopia de haz) o recurrir a desintegraciones radiactivas (espectroscopia de desintegración). Los detectores de semiconductor de germanio de alta pureza (HPGe) han demostrado tener una buena respuesta interaccionando con rayos gamma. Al igual que otros detectores de basados en s…

Optical characterization of nanowires for optoelectronic devices and energy harvesting

2019

This thesis presents a detailed investigation of the optical properties of Bi2Te3, GaN, InN, InP and GaN/AlN nanowires grown by different techniques for their application on future optoelectronic and thermoelectric devices. The thesis also includes a prototype of hybrid solar cell. The outline of the thesis is organized as follows: Chapter 1 presents a bird's eye view of the content of the thesis. Chapter 2 reviews basic notions of epitaxial growth, fundamentals in the synthesis of the nanowires and experimental techniques used for characterization and their underlying theory. Although several characterization techniques are employed in this work, Raman spectroscopy is applied as the major …

Particle identification in ALICE: a Bayesian approach

2016

We present a Bayesian approach to particle identification (PID) within the ALICE experiment. The aim is to more effectively combine the particle identification capabilities of its various detectors. After a brief explanation of the adopted methodology and formalism, the performance of the Bayesian PID approach for charged pions, kaons and protons in the central barrel of ALICE is studied. PID is performed via measurements of specific energy loss ($\mathrm{d}E/\mathrm{d}x$) and time-of-flight. PID efficiencies and misidentification probabilities are extracted and compared with Monte Carlo simulations using high-purity samples of identified particles in the decay channels ${\rm K}^0_S \righta…

Multiplicity dependence of the average transverse momentum in pp, p–Pb, and Pb–Pb collisions at the LHC

2013

The average transverse momentum $\langle p_{\rm T}\rangle$ versus the charged-particle multiplicity $N_{\rm ch}$ was measured in p-Pb collisions at a collision energy per nucleon-nucleon pair $\sqrt{s_{\rm NN}}=5.02$ TeV and in pp collisions at collision energies of $\sqrt{s}=0.9$, 2.76, and 7 TeV in the kinematic range $0.15<p_{\rm T}<10.0$ GeV/$c$ and $|\eta|<0.3$ with the ALICE apparatus at the LHC. These data are compared to results in Pb-Pb collisions at $\sqrt{s_{\rm NN}}=2.76$ TeV at similar charged-particle multiplicities. In pp and p-Pb collisions, a strong increase of $\langle p_{\rm T}\rangle$ with $N_{\rm ch}$ is observed, which is much stronger than that measured in Pb-Pb colli…

Observation and Measurement of Forward Proton Scattering in Association with Lepton Pairs Produced via the Photon Fusion Mechanism at ATLAS

2020

The observation of forward proton scattering in association with lepton pairs (eþe− þ p or μþμ− þ p) produced via photon fusion is presented. The scattered proton is detected by the ATLAS Forward Proton spectrometer, while the leptons are reconstructed by the central ATLAS detector. Proton-proton collision data recorded in 2017 at a center-of-mass energy of ffiffiffi s p ¼ 13 TeV are analyzed, corresponding to an integrated luminosity of 14.6 fb−1. A total of 57 (123) candidates in the ee þ p (μμ þ p) final state are selected, allowing the background-only hypothesis to be rejected with a significance exceeding 5 standard deviations in each channel. Proton-tagging techniques are introduced f…