380 research outputs found
Herz-Type Hardy Spaces for the Dunkl Operator on the Real Line
2000 Mathematics Subject Classification: Primary 46F12, Secondary 44A15, 44A35We introduce some new weighted Herz spaces associated with the Dunkl
operator on R. Also we characterize by atomic decompositions the
corresponding Herz-type Hardy spaces. As applications we investigate the Dunkl
transform on these spaces and establish a version of Hardy inequality for
this transform.* The authors are supported by the DGRST research project 04/UR/15-02
The Bessel-Struve intertwining operator on â„‚
We give a description of all transmutation operators from the Bessel-Struve operator to the second-derivative operator. Next we define and characterize the mean-periodic functions on the space â„‹ of entire functions and we characterize the continuous linear mappings from â„‹ into itself which commute with Bessel-Struve operator
Caractérisation des émergences du piémont de jbel Ayachi : contrôle structural et impact du changement climatique
Le massif calcaire de jbel Ayachi (Haute Atlas de Midelt), montre une structure complexe liée aux calcaires karstiques du Lias. Les nombreuses sources du relief indiquent l’existence d’importantes réserves d'eau. Dans le but de caractériser cet aquifère et de préciser les relations hydrodynamiques entre les zones de recharges et les sources de l’aquifères, une méthodologie a été utilisée. Elle comporte la synthèse des données géologiques, l’utilisation des techniques d’analyse structurale couplées aux études des débits et des chroniques de pluies. Les résultats de cette étude ont permis d’établir une comparaison des conditions d’émergence des deux sources (Ain Tatiouine, Ain Anzar Oufounès) et de l’évolution de leurs paramètres hydrodynamiques. Et une bonne corrélation entre les zones de recharges et les zones d’émergences. Elles permettront, à terme d’établir l’influence des changements climatiques sur les comportements hydrodynamiques de ces émergences.Mots-clés : sources, jbel Ayachi, Haute Atlas, lias, calcaire, karstique, débit, pluie, hydrodynamique, recharge, fissuration, fluctuations, émergence.Characterization of emergences piedmont of Jbel Ayachi. Structural control, and impact of climate changeThe calcareous solid mass of jbel Ayachi (High atlas of Midelt), shows a structure complex related to karstic limestones of Lias. The many sources of the relief indicate the existence of important water reserves. In order to characterize the aquifer and to clarify the relationship between hydrodynamic areas and springs of recharge of the aquifers, a methodology was used. It involves the synthesis of geological data, the use of structural analysis techniques coupled with studies of flow and chronic rain. The results of this study were used to compare the conditions of emergence of the two springs (Ain Tatiouine, Ain Anzar Oufounès) and changes in their hydrodynamic parameters. And good correlations between areas of recharge areas and emergences. They will eventually establish the influence of climate change on the hydrodynamic behavior of these emergences.Keywords : spring, Jbel Ayachi, High Atlas, lias, limestone, karst, flow, rain, hydrodynamics, recharge, cracking, fluctuations, emergence
Solution Structures of the C-Terminal Domain of Cardiac Troponin C Free and Bound to the N-Terminal Domain of Cardiac Troponin I
The N-terminal domain of cardiac troponin I (cTnI) comprising residues 33−80 and lacking the cardiac-specific amino terminus forms a stable binary complex with the C-terminal domain of cardiac troponin C (cTnC) comprising residues 81−161. We have utilized heteronuclear multidimensional NMR to assign the backbone and side-chain resonances of Ca2+-saturated cTnC(81−161) both free and bound to cTnI(33−80). No significant differences were observed between secondary structural elements determined for free and cTnI(33−80)-bound cTnC(81−161). We have determined solution structures of Ca2+-saturated cTnC(81−161) free and bound to cTnI(33−80). While the tertiary structure of cTnC(81−161) is qualitatively similar to that observed free in solution, the binding of cTnI(33−80) results mainly in an opening of the structure and movement of the loop region between helices F and G. Together, these movements provide the binding site for the N-terminal domain of cTnI. The putative binding site for cTnI(33−80) was determined by mapping amide proton and nitrogen chemical shift changes, induced by the binding of cTnI(33−80), onto the C-terminal cTnC structure. The binding interface for cTnI(33−80), as suggested from chemical shift changes, involves predominantly hydrophobic interactions located in the expanded hydrophobic pocket. The largest chemical shift changes were observed in the loop region connecting helices F and G. Inspection of available TnC sequences reveals that these residues are highly conserved, suggesting a common binding motif for the Ca2+/Mg2+-dependent interaction site in the TnC/TnI complex
Halogen-free flame-retardant compounds. Thermal decomposition and flammability behavior for alternative polyethylene grades
The effect of six halogen-free flame retardant (FR) formulations was investigated on the thermal stability of two low-density polyethylenes (LDPE) and one linear low-density polyethylene (LLDPE), by means of thermogravimetric analysis (TGA) under nitrogen and air atmosphere. The relative data were combined with flammability properties and the overall performance of the FRs was correlated with the type of branching in the polyethylene grades and to their processing behavior. The thermal degradation kinetics was further determined based on the Kissinger and Coats-Redfern methods. In terms of flammability, the addition of a triazine derivative and ammonium polyphosphate at a loading of 35 wt. %. was found to be the most efficient, leading to UL 94 V0 ranking in the case of the LDPE grade produced in an autoclave reactor. - 2019 by the authors.Funding: This publication was made possible by the NPRP award [NPRP 9-161-1-030] from the Qatar National Research Fund (a member of The Qatar Foundation). The statements made herein are solely the responsibility of the author(s)
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