33 research outputs found

    Representation of Lukasiewicz algebras by means of ordered stone spaces

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    AbstractIn this paper the author defines the notion of a θ-valued Ordered Lukasiewicz Space and a study of the dual of the category of θ-valued Lukasiewicz algebras, using ordered topological spaces, is given

    Optoelectronic and stability properties of quasi-2D alkylammonium based perovskites

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    Electronic and stability properties of quasi-2D alkylammonium perovskites are investigated using density functional theory (DFT) calculations and validated experimentally on selected classes of compounds. Our analysis is focused on perovskite structures of formula (A)2_2(A')n1_{n-1}Pbn_nX3n+1_{3n+1}, with large cations A = butyl-, pentyl-, hexylammonium (BA, PA, HXA), small cations A' = methylammonium, formamidinium, ethylammonium, guanidinium (MA,FA,EA,GA) and halogens X = I, Br, Cl. The role of the halogen ions is outlined for the band structure, stability and defect formation energies. Two opposing trends are found for the absorption efficiency versus stability, the latter being assessed with respect to possible degradation mechanisms. Experimental validation is performed on quasi-2D perovskites based on pentylammonium cations, namely: (PA)2_2PbX4_4 and (PA)2_2(MA)Pb2_2X7_7, synthesized by antisolvent-assisted vapor crystallization. Structural and optical analysis are inline with the DFT based calculations. In addition, the thermogravimetric analysis shows an enhanced stability of bromide and chloride based compounds, in agreement with the theoretical predictions.Comment: 8 pages, 8 figure

    The semiring-theoretic approach to MV-algebras: a survey

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    In this paper we review some of the main achievements of the semiring-theoretic approach to MV-algebras initiated and pursued mainly by the present authors and their collaborators. The survey focuses mainly on the connections between MV-algebras and other theories that such a semiringbased approach enabled, and on an application of such a framework to Digital Image Processing. We also give some suggestions for further developments by stating several open problems and possible research lines.Comment: Published versio

    Safety Management Manual ICAO Doc 9859 AN/474, Book review

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    On values in relatively normal lattices

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    AbstractIn [8, 11, 12] the class IRN was introduced in order to obtain the lattice-theoretic analogues of some results of Conrad (see e.g. [4]). The aim of these paper is to provide other useful constructions in the study of the structure of relatively normal lattices. The introduced notions and results are purely lattice-theoretic extensions of notions and results for lattice-ordered groups [2, 4, 5]. In the second section, the notion of plenary set of a member of the class IRN is introduced and the characterization of maximal plenary sets is given, extending a well-known theorem in l-groups. In the third section with any lattice in IRN is associated a tree and we investigate how the properties of this tree are reflected in the structure of the lattice. For the case of l-groups, one gets some of Conrad's results in [5]

    Prediction of Equilibrium Phase, Stability and Stress-Strain Properties in Co-Cr-Fe-Ni-Al High Entropy Alloys Using Artificial Neural Networks

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    High entropy alloys (HEAs) are still a largely unexplored class of materials with high potential for applications in various fields. Motivated by the huge number of compounds in a given HEA class, we develop machine learning techniques, in particular artificial neural networks, coupled to ab initio calculations, in order to accurately predict some basic HEA properties: equilibrium phase, cohesive energies, density of states at the Fermi level and the stress-strain relation, under conditions of isotropic deformations. Known for its high tensile ductility and fracture toughness, the Co-Cr-Fe-Ni-Al alloy has been considered as a test candidate material, particularly by adjusting the Al content. However, further enhancement of the microstructure, mechanical and thermal properties is possible by modifying also the fractions of the base alloy. Using deep neural networks, we map structural and chemical neighborhood information onto the quantities of interest. This approach offers the possibility for an efficient screening over a huge number of potential candidates, which is essential in the exploration of multi-dimensional compositional spaces

    Suspension of the penis – dissection, anatomical description and highlighting of anatomical risks in sectioning the suspensory ligaments

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    Abstract Background The suspension of the penis is provided by two ligaments: fundiform and suspensory. These ligaments are sectioned during some augmentative surgical procedures. The structure, the relations and the variability of these ligaments have been demonstrated. The penile neurovascular bundle and its relationships have also been emphasized. A clear knowledge of these details should ensure a reduction of the risk of surgical injury during augmentation procedures. Results We dissected the ligaments providing the suspension of the penis in 7 formalized corpses. We identified, for each of the ligaments, the origin, the insertion and the relations. The dissection pieces were photographed and the images obtained were discussed upon. We described the variability of the anatomical distribution and highlighted the relations with the vascular and nervous structures for each of these ligaments. The anatomical variability of the fascia and the relations with the base of the penis were also emphasized. For the suspensory ligament, we identified three groups of fibers through which it is attached to the penile body. Conclusions The dissections were conducted in layers, corresponding to the operative steps for the penile augmentation procedures. We believe that our study highlights the anatomical basis necessary to safely perform these surgeries. The study contributes to the description of the anatomical variability of the ligaments and logically presents details that contribute to preventing most surgical incidents
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