Approximations from Anywhere and General Rough Sets

Not all approximations arise from information systems. The problem of fitting approximations, subjected to some rules (and related data), to information systems in a rough scheme of things is known as the \emph{inverse problem}. The inverse problem is more general than the duality (or abstract representation) problems and was introduced by the present author in her earlier papers. From the practical perspective, a few (as opposed to one) theoretical frameworks may be suitable for formulating the problem itself. \emph{Granular operator spaces} have been recently introduced and investigated by the present author in her recent work in the context of antichain based and dialectical semantics for general rough sets. The nature of the inverse problem is examined from number-theoretic and combinatorial perspectives in a higher order variant of granular operator spaces and some necessary conditions are proved. The results and the novel approach would be useful in a number of unsupervised and semi supervised learning contexts and algorithms.Comment: 20 Pages. Scheduled to appear in IJCRS'2017 LNCS Proceedings, Springe

Effective Quantum Dynamics of Interacting Systems with Inhomogeneous Coupling

We study the quantum dynamics of a single mode/particle interacting inhomogeneously with a large number of particles and introduce an effective approach to find the accessible Hilbert space where the dynamics takes place. Two relevant examples are given: the inhomogeneous Tavis-Cummings model (e.g., N atomic qubits coupled to a single cavity mode, or to a motional mode in trapped ions) and the inhomogeneous coupling of an electron spin to N nuclear spins in a quantum dot.Comment: 9 pages and 10 figures, new version, accepted in Physical Review

Off-gassing of charred pellets during storage

The off-gassing tests for six types of charred pellets: canola straw, willow, bagasse, wheat straw, switchgrass and miscanthus, were conducted at room temperature 25±2 °C in sealed storage containers. Pairs of 2-litre sealable glass containers were filled with 800 g of each sample to approximately 75% of the container volume. One container contained charred pelles. The other container contained uncharred (untreated pellets). The two glass containers were sampled in alternate weeks for CO2, CO, O2, and CH4. Please click on the file below for full content of the abstract

Marine fisheries in Gujarat

A brief account of marine fish landings in Gujarat during 1985- 95 is given in this paper. Contribution of different gears along with the CPUE and the regionwise as well as groupwise details are also presented. The status and prospect of marine fisheries ofihe state is discussed with the aid of last 5 decades landing data

Development of Fluorescent Chemosensors for Calcium and Lead Detection

This work was supported by the Associate Laboratory for Green Chemistry—LAQV which is financed by national funds from FCT-MCTES (UIDB/50006/2020 and UIDP/50006/2020). L. J. G. acknowledges FCT-MCTES for a doctoral grant (UI/BD/153617/2022). The NMR spectrometers are part of Rede Nacional de RMN (PTNMR), supported by FCT-MCTES (grant ROTEIRO/0031/2013—PINFRA/22161/2016) (co-financed by FEDER through COMPETE 2020, POCI, and PORL and FCT through PIDDAC). The X-ray infrastructure was financed by FCT-MCTES through project RECI/BBB-BEP/0124/2012. Publisher Copyright: © 2024 by the authors.In the present work, several coumarin-3-carboxamides with different azacrown ether moieties were designed and tested as potential luminescent sensors for metal ions. The derivative containing a 1-aza-15-crown-5 as a metal chelating group was found to yield the strongest response for Ca2+ and Pb2+, exhibiting an eight- and nine-fold emission increase, respectively, while other cations induced no changes in the optical properties of the chemosensor molecule. Job’s plots revealed a 1:1 binding stoichiometry, with association constants of 4.8 × 104 and 8.7 × 104 M–1, and limits of detection of 1.21 and 8.04 µM, for Ca2+ and Pb2+, respectively. Computational studies suggest the existence of a PET quenching mechanism, which is inhibited after complexation with each of these two metals. Proton NMR experiments and X-ray crystallography suggest a contribution from the carbonyl groups in the coumarin-3-carboxamide fluorophore in the coordination sphere of the metal ion.publishersversionpublishe

Effect of H₂S and HCl contaminants on nickel and ceria pattern anode solid oxide fuel cells

In this study, with the motivation of elucidating the effect of H2S and HCl on solid oxide fuel cell anodes, nickel and ceria pattern anodes are prepared on yttrium-stabilized zirconia electrolyte, and the effect of H2S and HCl on their performance is tested using electrochemical impedance spectroscopy. However, it has been found that while H2S adversely impacts both nickel and ceria, the poisoning caused is reversible for nickel and only partially reversible for ceria. Poisoning kinetics are similar and fast for both materials, while recovery kinetics are slower for ceria than nickel. High sulfur coverage is the rate-limiting factor inferred from the elementary kinetic modeling. Unlike H2S, the presence of HCl appeared to be favorable for electrochemical oxidation as the polarization resistance of both pattern electrode cells decreased upon feeding HCl contaminated hydrogen gas. Similar behavior has not been reported previously, and the conclusion regarding underlying mechanisms requires further investigation

High pressure study of BaFe2As2 - role of hydrostaticity and uniaxial stress

We investigate the evolution of the electrical resistivity of BaFe2As2 single crystals with pressure. The samples used were from the same batch grown from self flux and showed properties that were highly reproducible. Samples were pressurised using three different pressure media: pentane-isopentane (in a piston cylinder cell), Daphne oil (in an alumina anvil cell) and steatite (in a Bridgman cell). Each pressure medium has its own intrinsic level of hydrostaticity, which dramatically affects the phase diagram. An increasing uniaxial pressure component in this system quickly reduces spin density wave order and favours the appearance of superconductivity, similar to what is seen in SrFe2As2.Comment: 11 page