43 research outputs found
Towards greater selectivity and peak capacities in multidimensional separations of complex samples
In this thesis, the focus was on understanding recent developments in liquid chromatography (LC) and how these can be applied to improve two-dimensional separations (Chapter 2). The main advances that were of interest for the design of a 3D separation device were those in column technology, instrument capabilities and miniaturized separation devices. We proceeded with an investigation into the miniaturization of comprehensive two-dimensional LC (LC×LC) for the analysis of peptides by direct coupling with a high-resolution mass spectrometer (HR-MS) (Chapter 4). In choosing the best combination of retention mechanisms for the LC×LC system, we have investigated computational programs for the prediction of retention and the optimization of peptide separations in hydrophilic-interaction liquid chromatography (HILIC) and reversed-phase liquid chromatography (RPLC) (Chapter 3). Finally, we investigated the introduction of particles in a 3D-printed device as a model for a future 3D-spatial-separation device (Chapter 5). To reach the ultimate goal of a 3D-spatial-separation device with the capability of achieving a peak capacity of one million, further research is still required. The future outlook following the research in this thesis is described in Chapter 6
Tribological behavior of AA1050H24-graphene nanocomposite obtained by friction stir processing
The tribological behavior of a new composite material containing graphene nanosheets (GNS) is presented. The composite material was obtained by Friction Stir Processing, using as metallic matrix the AA1050-H24 alloy. Different tool rotation and advancing speeds were tested in friction stir processing (FSP). The worn surfaces of obtained materials were analyzed by Scanning Electron Microscopy (SEM). Raman spectroscopy demonstrated that graphene reinforcements are successfully mixed into the aluminum matrix. The results proved the feasibility of using GNSs to obtain nanocomposites by FSP. The coefficient of friction of the aluminum alloy was 0.57, decreasing to 0.38 for the nanocomposite GNSs/AA1050. These values decrease for samples obtained at lower tool rotation speeds. The weight losses of the composites are less than that of unreinforced AA1050-H24 alloy for conditions with lower advancing speeds (40 and 60 mm/min) and 1120 rpm. © 2018 by the authors. Licensee MDPI, Basel, Switzerland
Three body systems with strangeness and exotic systems
We report on four 's and three 's, in the 1500 - 1800 MeV
region, as two meson - one baryon S-wave resonances found by solving
the Faddeev equations in the coupled channel approach, which can be associated
to the existing = -1, low lying baryon resonances. On the
other hand we also report on a new, hidden strangeness state, mostly made
of , with mass around 1920 MeV, which we think could be
responsible for the peak seen in the around this
energy. Finally we address a very novel topic in which we show how few body
systems of several mesons can be produced, with their spins aligned up
to J=6, and how these states found theoretically can be associated to several
known mesons with spins J=2,3,4,5,6.Comment: Talk at the 21st European Conference on Few Body Problems in Physics,
Salamanca, Sep. 201
Dynamically generated resonances from the vector octet-baryon decuplet interaction
We study the interaction of the octet of vector mesons with the decuplet of
baryons using Lagrangians of the hidden gauge theory for vector interactions.
The unitary amplitudes in coupled channels develop poles that can be associated
with some known baryonic resonances, while there are predictions for new ones
at the energy frontier of the experimental research. The work offers guidelines
on how to search for these resonances
Study of the , , and in the radiative decays
In this paper we present an approach to study the radiative decay modes of
the into a photon and one of the tensor mesons ,
, as well as the scalar ones and .
Especially we compare predictions that emerge from a scheme where the states
appear dynamically in the solution of vector meson--vector meson scattering
amplitudes to those from a (admittedly naive) quark model. We provide evidence
that it might be possible to distinguish amongst the two scenarios, once
improved data are available.Comment: The large Nc argument improved; version published in EPJA