Search results for "Ray"
showing 10 items of 8009 documents
A method for measuring wetting and swelling of bentonite using X-ray imaging
2022
A non-invasive method based on X-ray imaging for measuring deformation and water transport in wetting and swelling bentonite samples is introduced. Sequential X-ray images taken of the samples were used to calculate the attenuation coefficient and deformation. These results, together with careful calibration, allowed finding the dry density and water content distributions and their temporal evolution in the wetting and swelling samples. A specific correction technique, based on regularly taking reference X-ray images of aluminum plates of varying thickness, was developed and used to take into account X-ray beam instabilities and thus to improve the accuracy of density analysis. Large deform…
1,1,4,4-Tetramethylpiperazinediium dibromide
2009
A small quantity of the title compound, C8H20N22+·2Br−, was formed as a by-product in a reaction between a diamine and an alkyl bromide. The asymmetric unit contains half of a centrosymmetric dication and a bromide anion. In the crystal, weak intermolecular C—H...Br hydrogen bonds consolidate the crystal packing.
MbCo in Saccharide Solid Amorphous Systems: A Combined FTIR and SAXS Study
2011
Saccharides, and in particular trehalose, are known for their efficiency in protecting biostructures against environmental stress [1], although the preservation mechanism is still debated. Experiments and simulations [2,3] on carboxy-myoglobin (MbCO) showed that the protein dynamics is highly inhibited in dry trehalose matrices, the inhibition being dependent on the water content. In these conditions, a mutual protein-matrix structural and dynamic influence is observed.Here we report a combined FTIR and SAXS study on MbCO embedded in dry amorphous matrices of trehalose and sucrose. FTIR measurements were performed at different protein/sugar ratios, focussing on the stretching band of the bo…
Apparenti disegni eretici
2022
Il vocabolario Zingarelli, tra i significati del termine ‘eresia’, riporta: “nelle religioni fondate su una dogma- tica universalmente o ufficialmente riconosciuta, dottrina basata su interpretazioni personali in contra- sto con la tradizione” oppure “opinione erronea o contrastante con quelle più comunemente seguite” e, in ultimo “discordia”. È eretico quindi colui che ha scelto, chi sostiene principi contrari ad una ideolo- gia. Uno degli aspetti dell’architettura, quello probabilmente più confortante, è il disegno inteso nel dop- pio significato di intenzione e di rappresentazione di qualcosa di reale o immaginato; gli schizzi, nei loro tratti essenziali, comunicano un pensiero, un’i…
Analysis of microtomographic images of porous heterogeneous materials
2015
In this work, we study the phases of image processing chain of microtomographic imag- ing in order to obtain reliable results while optimizing the time spent on denoising and segmentation. We consider that the decisions made at the early phases of the processing chain are most important and the selection made there essentially determine the overall quality of imaging process. We also compare here various denoising method qualita- tively, however, we think that the pure noise removal ability is not the only requirement for noise removal in microtomographic images. By proper denoising we can affect selec- tion of segmentation methods and, thus, also the quality of the analysis. Additionally, …
Entrapment of a linear water pentamer into a uranyl-salophen dimer in the solid state
2019
In the solid state, uranyl-salophen complex 1, decorated with bipyridyl sidearms, self-assembles from moist acetonitrile into dimeric species displaying a confined water pentamer, as observed by X-...
Estudio estructural y aplicaciones en detección de diversas sondas moleculares cromogénicas y fluorogénicas
2016
El reconocimiento molecular y el desarrollo de quimiosensores son campos de enorme interés dentro de la química supramolecular. Las sondas moleculares cromogénicas y fluorogénicas han sido objeto de estudio en nuestro grupo de investigación para el reconocimiento de especies iónicas y neutras de interés biológico o medioambiental. Los sistemas de detección cromogénicos se caracterizan por una respuesta rápida y detectable muchas veces por el ojo humano, mientras que los sensores fluorogénicos son sistemas extremadamente sensibles. Uno de los factores cruciales en la selectividad y la eficacia del sensor es la elección del disolvente en el cual tendrá lugar la interacción con el analito ya q…
Predicted gamma-ray image of SN 1006 due to inverse Compton emission
2009
We propose a method to synthesize the inverse Compton (IC) gamma-ray image of a supernova remnant starting from the radio (or hard X-ray) map and using results of the spatially resolved X-ray spectral analysis. The method is successfully applied to SN 1006. We found that synthesized IC gamma-ray images of SN 1006 show morphology in nice agreement with that reported by the H.E.S.S. collaboration. The good correlation found between the observed very-high energy gamma-ray and X-ray/radio appearance can be considered as an evidence that the gamma-ray emission of SN 1006 observed by H.E.S.S. is leptonic in origin, though the hadronic origin may not be excluded.
Deep-learning based reconstruction of the shower maximum X max using the water-Cherenkov detectors of the Pierre Auger Observatory
2021
The atmospheric depth of the air shower maximum $X_{\mathrm{max}}$ is an observable commonly used for the determination of the nuclear mass composition of ultra-high energy cosmic rays. Direct measurements of $X_{\mathrm{max}}$ are performed using observations of the longitudinal shower development with fluorescence telescopes. At the same time, several methods have been proposed for an indirect estimation of $X_{\mathrm{max}}$ from the characteristics of the shower particles registered with surface detector arrays. In this paper, we present a deep neural network (DNN) for the estimation of $X_{\mathrm{max}}$. The reconstruction relies on the signals induced by shower particles in the groun…
Diammine{N-[2-(hydroxyimino)propionyl]-N'-[2-(oxidoimino)propionyl]propane-1,3-diaminido-κ4 N,N',N'',N'''}iron(III)
2012
In the title compound, [Fe(C9H13N4O4)(NH3)2], the FeIII atom, lying on a mirror plane, is coordinated by four N atoms of a triply deprotonated tetradentate N-[2-(hydroxyimino)- propionyl]-N0 -[2-(oxidoimino)propionyl]propane-1,3-diaminide ligand in the equatorial plane and two N atoms of two ammonia molecules at the axial positions in a distorted octahedral geometry. A short intramolecular O—HO hydrogen bond between the cis-disposed oxime O atoms stabilizes the pseudo-macrocyclic configuration of the ligand. In the crystal, molecules are linked by N—HO hydrogen bonds into a three-dimensional network. The ligand has a mirror-plane symmetry. One of the methylene groups of the propane bridge i…