Search results for "Barium"
showing 10 items of 262 documents
Second-step typification of Statice insignis, basionym of Limonium insigne (Plumbaginaceae)
2017
Cosson (1852: 177) described Statice insignis (Plumbaginaceae Juss.), providing a detailed description of this species, reporting several localities of provenance and indicating a pertinent gathering by the French traveler and plant collector Eugène Bourgeau: “In salsuginosis Hispaniae australioris, in regno Granatensi ad urbem Vera (E. Bourgeau, pl. Esp. n. 1442) et ad oppidula Santa-Fe et Roqueta (E. Bourgeau, 1851)”.
The comparative biology of the closely related Senecio nebrodensis and S. viscosus, a narrow endemic and a widespread ruderal
1993
The closely related Senecio nebrodensis, a perennial herb from four mountain ranges in Spain, and S. viscosus, an annual herb widespread in Europe, are being compared by the study of herbarium material and comparative cultivation. In cultivation, S. nebrodensis behaved as an annual, completing its life cycle within a shorter period of time than S. viscosus. The formation of basal leaf rosettes is much more pronounced in S. nebrodensis than in S.viscosus. The main difference between the two species, however, is their breeding system. While S. nebrodensis is self-incompatible, S. viscosus is self-compatible. Differences in reproductive morphology (mainly size and number of ray florets) are su…
Structural and conductivity study of the proton conductor BaCe(0.9−x)ZrxY0.1O(3−ı) at intermediate temperatures.
2009
International audience; The perovskite BaCe(0.9−x)ZrxY0.1O(3−ı) is prepared by solid-state reaction at 1400 ◦C and sintering at 1700 ◦C. It is characterised using X-ray diffraction, Raman spectroscopy and electrical measurements. A distortion fromthe cubic structure at roomtemperature is noticeable in the Raman spectra for 0.2 < x < 0.8, but not in the X-ray diffraction patterns. This work points out the rhombohedral nature of this distortion. Phase transitions are studied up to 600 ◦C. The direct current conductivity is measured as a function of oxygen partial pressure, and at a water vapour partial pressure of 0.015 atm. The total conductivity is resolved into an ionic and a p-type compon…
Possible Ca 2+ -dependent mechanism of apical outer hair cell modulation within the cochlea of the guinea pig
1998
Calcium ions were precipitated with potassium antimonate after injection of the inorganic calcium channel blocker MnCl2 or the inorganic potassium channel blockers BaCl2 or CsCl into the perilymph of the scala vestibuli of the guinea pig. The spatial distribution of the formed histochemical reaction products within the organ of Corti was studied by energy-filtering transmission-electron microscopy. Compared with untreated control ears, the number of the formed precipitates drastically increased at the extracellular side of the lamina reticularis after application of the various inorganic channel blockers. The apical side of the outer hair cells and the intervening Deiter cells were covered …
The impact of Information Technology on the identification of species and archiviation of taxonomic and floristic data.
2007
In plant taxonomy, classification aims at reconstructing an evolutionary history, usually represented by means of phylogenetic trees. The approach followed by the classification is hierarchical, and rather in coherence with the dichotomies traditionally used for identifying a certain species. But classification and identification are different, since the latter just aims at finding the name of a specimen, eventually in order to get information on it. There are many ways to identify a specimen: to trace it back to its origin, by following the bifurcations of its phylogenetic tree is one possibility, but not always the easiest and quickest one. This theme has been touched during the symposium…
Synthesis and Crystal Structure of a Novel Lamellar Barium Derivative: Ba(VOPO4)2·4H2O. Synthetic Pathways for Layered Oxovanadium Phosphate Hydrate…
1997
A unified synthetic strategy has allowed us to rationalize the preparative chemistry of the layered oxovanadium phosphates M(VOPO4)2·nH2O. Thus, we have been able to isolate as single phases with reasonable yields both all the previously characterized phosphates and a new solid containing Ba2+ cations as guest species as well as to prepare new related derivatives involving arsenate anions. In order to organize the experimental results, we have used two complementary models: a simple restatement of the partial charge model (PCM), and the valence matching principle (VMP) (derived from the bond valence method). The crystal structure of the new barium lamellar derivative, Ba(VOPO4)2·4H2O, has …
5-Oxo-1,4-dihydroindenopyridines: Calcium modulators with partial calcium agonistic activity
1990
The title compounds 4a-g were prepared by Knoevenagel reactions of 1,3-indandione (1) with the aromatic aldehydes 2a-g followed by cyclizing Michael addition of the products thus obtained with methyl β-aminocrotonate (3). The structures of products 4 were characterized by spectal data. Positive inotropic activities were observed on electrically stimulated, left atria of giunea pigs and these effects could be attributed to calcium agonism. On the other hand, barium chloride-induced contractions of guinea pig ileum were inhibited in a dose-dependent manner.
ChemInform Abstract: 5-Oxo-1,4-dihydroindenopyridines: Calcium Modulators with Partial Calcium Agonistic Activity.
1990
The title compounds 4a-g were prepared by Knoevenagel reactions of 1,3-indandione (1) with the aromatic aldehydes 2a-g followed by cyclizing Michael addition of the products thus obtained with methyl β-aminocrotonate (3). The structures of products 4 were characterized by spectal data. Positive inotropic activities were observed on electrically stimulated, left atria of giunea pigs and these effects could be attributed to calcium agonism. On the other hand, barium chloride-induced contractions of guinea pig ileum were inhibited in a dose-dependent manner.
Insect pests of the Herbarium of the Palermo botanical garden and evaluation of semiochemicals for the control of the key pest Lasioderma serricorne …
2020
Abstract The herbaria are scientific tools of great importance that preserve extinct, rare, endemic, and common plant species and also have importance as Cultural Heritage for their historical and esthetical value. Herbaria can be infested by several insect pests feeding on dried plants, and their management is often complicated and difficult as the use of chemical insecticides can have negative drawbacks. This suggests a strong need for alternative control tools such as the use of semiochemicals to develop Integrated Pest Management (IPM) programs. In order to identify the main insect pests that determine the damages on the exsiccata stored in the Palermo Botanical Garden's Herbarium, one …
Adsorption of water vapor on X and Y zeolites exchanged with barium
2001
Abstract The adsorption of water vapor on BaY and BaX zeolites is studied by thermogravimetry and calorimetry under isothermal or isobaric conditions. The faujasite zeolite exhibits a stronger adsorption affinity for water molecules with barium than with sodium or potassium as exchangeable cations. The adsorption–desorption isotherm at 150°C shows a hysteresis loop attributed to the migration of compensating cations during their interaction with water molecules. Calorimetric measurements and the Dubinin–Radushkevich’s model both show that the adsorption of water occurs via a three-step mechanism: adsorption on compensating cations, formation of a monolayer on the walls and multilayer adsorp…