A terra sigillata do fundeadouro de Tróia

The terra sigillata, subject of this paper, is part of the collection of underwater archaeological finds of roman period that came from the whirl-pool of Tróia, deposited in the Centro Portugués de Actividades Subaquaticas. Although these objects were collected without an effective depositional context, they are important indicators of chronologies and provenience of importations. Through the typological analysis is possible to approach some problems. This work meant to be the first step to the exhaustive study and systematic treatment of this fluvial area with natural characteristics proper to anchor boats. It is a fundamental space, not only, for the understanding of the waterfront of Tróia's industrial centre of fish preserves, but also, the dynamic of River Sado's estuary in Antiquity

A terra sigillata do fundeadouro de Tróia

The terra sigillata, subject of this paper, is part of the collection of underwater archaeological finds of roman period that came from the whirl-pool of Tróia, deposited in the Centro Portugués de Actividades Subaquaticas. Although these objects were collected without an effective depositional context, they are important indicators of chronologies and provenience of importations. Through the typological analysis is possible to approach some problems. This work meant to be the first step to the exhaustive study and systematic treatment of this fluvial area with natural characteristics proper to anchor boats. It is a fundamental space, not only, for the understanding of the waterfront of Tróia's industrial centre of fish preserves, but also, the dynamic of River Sado's estuary in Antiquity

Synthesis of Hydroxyapatite/Iron Oxide Composite and Comparison of Selected Structural, Surface, and Electrochemical Properties

The paper presents the synthesis of a hydroxyapatite/iron oxide composite utilizing the wet chemical method, as well as the comparison of several selected material characteristics. As follows from the literature reports, hydroxyapatite is a common mineral possessing numerous significant properties. Nowadays, there is an increase in the amount of research on possible modifications of this compound. The promising way to improve hydroxyapatite features is its combination with iron oxide. Particularly, there can be two forms that are distinguished, namely Fe3O4 and γ-Fe2O3. These oxides exhibit valuable properties, particularly magnetism. A combination of the mentioned materials leads to multifunctional composite formation with many potential applications, as follows from several studies. However, this area of science is not fully developed. There are still many aspects to be examined. The synthesized composite and its components were analyzed by employing the following methods. The X-ray diffraction analysis revealed formation of hydroxyapatite and Fe2O3 crystalline phases. Moreover, porosimetry proved a larger specific area for the composite sample in comparison with other materials. The results obtained using the SEM method confirmed an external layer of hydroxyapatite and spherical shapes of internal Fe2O3 particles. Furthermore, the X-ray photoelectron spectroscopy data presented characteristic peaks of Fe, Ca, P, and O atoms in all samples. The Fourier Transform Infrared spectra displayed all the specific vibrations typical of the analyzed materials. What is more, the Vibrating Sample Magnetometer method confirmed the paramagnetic nature of the samples. It could be concluded that the synthesized composite has intermediate properties between the components used in the formation process. The results suggest that these composites are superparamagnetic. This type of material architecture would be well suited for biomedical applications

Search for resonant pair production of Higgs bosons decaying to bottom quark-antiquark pairs in proton-proton collisions at 13 TeV

A search for a narrow-width resonance decaying into two Higgs bosons, each decaying into a bottom quark-antiquark pair, is presented. The search is performed using proton-proton collision data corresponding to an integrated luminosity of 35.9 fb$^{−1}$ at $\sqrt{s}=13$ TeV recorded by the CMS detector at the LHC. No evidence for such a signal is observed. Upper limits are set on the product of the production cross section for the resonance and the branching fraction for the selected decay mode in the resonance mass range from 260 to 1200 GeV