Search results for "Microstructure"
showing 10 items of 707 documents
Lithium intercalation chemistry, microstructure and superconductivity in zirconium and hafnium nitride halides
2000
Abstract Lithium intercalation in β-MNX (M=Zr, Hf; X=Cl, Br) leads to superconducting compounds with critical temperatures between 12 and 24 K. The lithium uptakes after treatment of the host materials with n-butyllithium/hexane solutions are ca. 0.2 atoms per formula for β-ZrNCl and β-ZrNBr, and between 0.07 and 0.67 for β-HfNCl. Electrochemical lithiation experiments agree with the results obtained with chemical methods, as samples with larger capacity on discharge are also those having larger lithium contents after chemical lithiation. Variations exist in the electrochemical profiles of different batches for the three compounds indicating differences in the intercalation reaction pathway…
Investigations of the Microstructure of Lipid Interface Films
1990
The phase behaviour of phospholipid monolayers at electrolyte/gas interfaces is studied by fluorescence microscopy. At the LE/LC phase transition, phase separation leads to a Wigner-type lattice structure. The observations are quantified using digital image processing. The results show that the phase transition comprises three different regimes.
Effectiveness of Preservative Treatments on Coloured Ruditic Building Stones
2009
: The dark grey Breccia di Billiemi and the Ammonitico Rosso of Piana degli Albanesi, two coloured stones widely used in monuments both outdoor and indoor in Sicily, undergo significant decay as effect of weathering: colour change and development of surface microcracks which affect not only the chromatic aspect but also the state of aggregation. In a previous study (Fracture and Failure of Natural Building Stones, 2006, Springer, Dordrecht, The Netherlands: 329), such effects were successfully reproduced on laboratory samples by means of artificial accelerated weathering and the different response of veins and grains to the ageing agents was related to the microstructure of stones. In this…
Pilna teikuma definīciju analīze 'Kobilda' vārdnīcās
2021
Šajā bakalaura darbā tiek pētītas pilna teikuma definīcijas un to īpatnības KOBILDA vārdnīcās. KOBILDA pilna teikuma definēšanas stils kļuva par pavērsienu vārdnīcu pasaulē, piedāvājot pilnīgi jaunu pieeju vārdnīcu rakstīšanai. Tādējādi bakalaura darbā ir iekļauti secinājumi, kas atspoguļo lietotāju attieksmi pret KOBILDA definīciju. Darba empīriskā pētījuma metode ir gadījumu izpēte, datu vākšanas tehnika – aptaujas anketēšana, kas ir analizēta no kvalitatīvā un kvantitatīvā viedokļa. Analīze atklāj, ka pilna teikuma definīcijas nav priekšroka salīdzinājumā ar citiem definīciju veidiem, jo lielākā daļa respondentu dod priekšroku tradicionālākiem definēšanas stiliem. Turklāt analīze rāda, k…
Microstructural and magnetic characterization of dusts from a stone crushing industry in Birbhum, India
2010
Abstract Stone dust sample collected from a stone crushing industry situated at Muhammad Bazar in Birbhum, India, is studied for its physical characterization using various techniques. Morphology and compositional analysis of the stone dust by scanning electron microscopy (SEM) reveal that the dust is an agglomeration of many tiny particles (0.32–2.12 μm), mostly having sharp edges, as well show microstructure heterogeneity. Elements present in the sample are detected by energy dispersive X-ray spectrometry (EDX). The X-ray diffraction (XRD) pattern analysis shows that the sample mainly contains minerals like anorthite, augite, esseneite and albite. An overall antiferromagnetic interaction …
Phosphotungstic acid (PTA) in the synthesis of 3D CdS superstructures by diffusion assisted hydrothermal method
2015
Abstract In this study, the synthesis of cadmium sulfide (CdS) microstructures by gas diffusion assisted hydrothermal method using phosphotungstic acid (PTA) is reported. The as-synthesized products were characterized by Fourier transform infrared (FTIR), powder X-ray diffraction (XRD) and scanning electron microscopy (SEM). The effects of PTA dose, thioacetamide amount, time and temperature on the morphology of obtained particles have been studied. In this process, PTA ion host stabilizes the CdS particles against aggregation and thioacetamide plays two roles, being at the same time a sulfur source and a capping ligand. Based on the performed analyses it seems that the thioacetamide is mor…
Observaciones sobre algunos caracteres de valor taxonómico en el grupo de los carófitos
1990
The variability of the microstructurals characters and mineralogical composition of the oogonia of some charophytes extant and fossils is described. Two types of microstructures (W & V) are find. These are conservative into populations and are not able to change by the environmental factors. Moreover, these structures are quite constant in some of the phylogenetics groups studied. Consequently it is proposed its utilization in taxonomy. The apparition of original compounds in the Charophyta (vaterite. whewelite, aragonite, etc.) is important because it supports an old idea that considerates the Charophyta as an autonomous class between the Clorophyta and the Traqueophyta.<br><b…
Microstructure and characteristic properties of dogfish skin gelatin gels prepared by freeze/spray-drying methods
2020
International audience; The effects of two pretreatments (microwaves or oven-drying) on the dogfish (Squalus acanthias) skin as well as two drying processes (freeze-drying or spray-drying) on the extracted gelatins were studied. Thus six types of gelatins were obtained, three of which were freeze-dried (FG) and the others were spray-dried (SG), from the untreated skin (US), microwaves-pretreated skin (MS) and oven-pretreated skin (OS). The highest yield (8.67%) was obtained for the OSFG, while the lowest one (3.06%) was measured for the OSSG. Interestingly, all gelatins exhibited relatively high protein (84.02-89.53%), and low lipid (0.50-1.71%) and ash (3.05-7.17%) contents. In addition, g…
Effect of oxidoreduction potential and of gas bubbling on rheological properties and microstructure of acid skim milk gels acidified with glucono-del…
2009
Milk oxidoreduction potential was modified using gases during the production of a model dairy product and its effect on gel setting was studied. Acidification by glucono-delta-lactone was used to examine the physicochemistry of gelation and to avoid variations due to microorganisms sensitive to oxidoreduction potential. Four conditions of oxidoreduction potential were applied to milk: milk was gassed with air, nongassed, gassed with N(2), or gassed with N(2)H(2). The rheological properties and microstructure of these gels were determined using viscoelasticimetry, measurement of whey separation, and confocal laser scanning microscopy. It appeared that a reducing environment led to less-aggre…
Microstructure, porosity and mineralogy around fractures in Olkiluoto bedrock
2012
3D distributions of minerals and porosities were determined for rock-core samples that included water-conducting fractures. The analysis of these samples was performed using conventional petrography methods, C-14-PMMA porosity analysis and X-ray tomography. It seems that the properties of rock around a water-conducting fracture depend on so many uncorrelated factors that no clear pattern emerged even for rock samples with a given type of fracture. We can conclude, however, that the present combination of methods can be used to infer novel structural information about alteration zones adjacent to fracture surfaces.