2,662 research outputs found
Four related benzazepine derivatives in a reaction pathway leading to a benzazepine carboxylic acid : hydrogen-bonded assembly in zero, one, two and three dimensions
The authors thank âCentro de Instrumentacion Cientıfico-Tecnica of Universidad de Jaenâ and the staff for data collection. AP, SAG and CMS thank Colciencias for financial support (grant No. 1102â521â28229). JC thanks the Consejerıa de Innovacion, Ciencia y Empresa (Junta de Andalucıa, Spain) and the Universidad de Jaen for financial support.(2R*,4S*)-Methyl 2,3,4,5-tetraÂhydro-1,4-epÂoxy-1H-benz[b]azepine-2-carboxylÂate, C12H13NO3, (I), and its reduction product (2R*,4S*)-methyl 4-hyÂdroxy-2,3,4,5-tetraÂhydro-1H-benz[b]azepine-2-carboxylÂate, C12H15NO3, (II), both crystallize as single enantiÂomers in the space group P212121, while the hydrolysis product (2RS,4SR)-4-hyÂdroxy-2,3,4,5-tetraÂhydro-1H-benz[b]azepine-2-carbÂoxyÂlic acid, C11H13NO3, (III), and the lactone (2RS,5SR)-8-(trifluoromethoxy)-5,6-dihydro-1H-2,5-methanobenz[e][1,4]oxazocin-3(2H)-one, C12H10F3NO3, (IV), both crystallize as racemic mixtures in the space group P21/c. The molÂecules of compound (IV) are linked into centrosymmetric R22(10) dimers by N-HO hydrogen bonds, and those of compound (I) are linked into chains by C-H(arene) hydrogen bonds. A combination of O-HO and O-HN hydrogen bonds links the molÂecules of comÂpound (III) into sheets containing equal numbers of R44(14) and R44(26) rings, and a combination of C-H(arene) hydrogen bonds and three-centre O-H(N,O) hydrogen bonds links the molÂecules of compound (II) into a three-dimensional frameÂwork structure. Comparisons are made with some related compounds.Publisher PDFPeer reviewe
Anisakis infection in allis shad, Alosa alosa (Linnaeus, 1758), and twaite shad, Alosa fallax (LacépÚde, 1803), from Western Iberian Peninsula Rivers : zoonotic and ecological implications
Acknowledgments The authors would like to thank M. N. Cueto and J.M. Antonio (ECOBIOMAR) for their excellent technical support and also Rodrigo LĂłpez for making the map of the study area. We also thank the personal of the Vigo IEO, for providing information about shad captures at sea collected on the basis of national program (AMDES) included in the European Data Collection Framework (DCF) project. We are also grateful to Comandancia Naval de Tui for providing fishing data. M. Bao is supported by a PhD grant from the University of Aberdeen and also by financial support of the contract from the EU Project PARASITE (grant number 312068). This study was partially supported by a PhD grant from the Portuguese Foundation for Science and Technology (FCT) SFRH/BD/44892/2008) and partially supported by the European Regional Development Fund (ERDF) through the COMPETEâOperational Competitiveness Programme and national funds through Foundation for Science and Technology (FCT), under the project BPEst-C/MAR/ LA0015/2013. The authors thank the staff of the Station of Hydrobiology of the USC BEncoro do Con^ due their participation in the surveys. This work has been partially supported by the project 10PXIB2111059PR of the Xunta de Galicia and the project MIGRANET of the Interreg IV BSUDOE (South-West Europe) Territorial Cooperation Programme (SOE2/P2/E288). D.J. NachĂłn is supported by a PhD grant from the Xunta de Galicia (PRE/2011/198)Peer reviewedPostprin
Internet of things: Conceptual network structure, main challenges and future directions
Internet of Things (IoT) is a key technology trend that supports our digitalized society in applications such as
smart countries and smart cities. In this study, we investigate the existing strategic themes, thematic evolution
structure, key challenges, and potential research opportunities associated with the IoT. For this study, we conduct
a Bibliometric Performance and Network Analysis (BPNA), supplemented by an exhaustive Systematic Literature
Review (SLR). Specifically, in BPNA, the software SciMAT is used to analyze 14,385 documents and 30,381
keywords in the Web of Science (WoS) database, which was released between 2002 and 2019. The results reveal
that 31 clusters are classified according to their importance and development, and the conceptual structures of
key clusters are presented, along with their performance analysis and the relationship with other subthemes. The
thematic evolution structure describes the important cluster(s) over time. For the SLR, 23 documents are
analyzed. The SLR reveals key challenges and limitations associated with the IoT. We expect the results will form
the basis of future research and guide decision-making in the IoT and other supporting industries.Coordenaç~ao de Aperfeiçoamento
de Pessoal de NĂvel Superior - Brazil (CAPES) - Finance Code 001
and the Spanish Ministry of Science and Innovation under grants
PID2019-105381 GA-100 (iScience)Consejo
Nacional de Ciencia y TecnologĂa (CONACYT) and Direcci on General de
Relaciones Exteriores (DGRI
On the validity of the 630 nm Fe I nm lines for the magnetometry of the internetwork quiet Sun
The purpose of this work is to analyze the reliability of the magnetic field
strengths inferred from the 630 nm pair of Fe I lines at internetwork quiet Sun
regions. Some numerical experiments have been performed that demonstrate the
inability of these lines to recover the magnetic field strength in such low
flux solar regions. It is shown how different model atmospheres, with magnetic
field strengths ranging from few hundred Gauss to kiloGauss, give rise to
Stokes profiles that can not be distinguished. The reasons for this degeneracy
are discussed.Comment: Accepted for publication in A&
Comparison of hierarchical temporal memories and artificial neural networks under noisy data
The ability of two different machine learning approaches to map non-linear problems from experimental data is evaluated under controlled experiments. A well-known machine learning algorithm (Artificial Neural Network) is compared against a new computing paradigm (Hierarchical Temporal Memory) under a controlled scenario. The chosen scenario is the detection of impacts in a cantilever beam under vibration instrumented with fiber Bragg gratings. The main characteristics of both of the machine learning approaches are analyzed while varying environmental parameters such as the number of sensing points and their location. From the achieved results some clues can be extracted regarding dealing with noisy or partial data using different machine learning approaches
Low-lying magnetic loops in the solar internetwork
The aim of this work is to study the structure of the magnetic field vector
in the internetwork and search for the presence of small-scale loops. We invert
1.56 micron spectropolarimetric observations of internetwork regions at disc
centre by applying the SIR code. This allows us to recover the atmospheric
parameters that play a role in the formation of these spectral lines. We are
mainly interested in the structure of the magnetic field vector. We find that
many opposite polarity elements of the internetwork are connected by short
(2-6''), low-lying (photospheric) loops. These loops connect at least the 10-20
% of the internetwork flux visible in our data. Also we have some evidence that
points towards a dynamic scenario which can be produced by the emergence of
internetwork magnetic flux.Comment: Accepted for publication in A&A letter
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