Search results for "MORPHOLOGY"
showing 10 items of 1425 documents
A comparative study of heterostructured CuO/CuWO4 nanowires and thin films
2017
Authors are grateful to Reinis Ignatans for XRD measurements.
Facile Large Scale Synthesis of WS2 Nanotubes from WO3 Nanorods Prepared by a Hydrothermal Route.
2005
Abstract Hexagonal WO 3 nanorods of 5–50 nm in diameter and 150–250 nm in length have been synthesised in gram quantities by a low temperature hydrothermal route using citric acid as a structural modifier and hexadecylamine as a templating agent. The ratio of [A]/[W] play an important role on WO 3 nanorods formation. These WO 3 nanorods were found highly suitable as a precursor for the synthesis of a good yield of multiwalled WS 2 nanotubes by reducing them with H 2 S at 840 °C for 30 min. The length and the wall thickness of the WS 2 nanotubes could be altered by controlled reduction of the oxide precursor. The morphology, structure and the composition of the WO 3 nanorods and WS 2 nanotub…
Electrical Characterization of the Fe-Doped BT Ceramics by an Impedance Spectroscopy
2015
The electric properties of the Fe - doped BaTiO3 ceramics was investigated as a function of frequency and temperature. The structure and morphology of investigated sample were characterized by an X-ray diffraction and scanning electron microscopy. The impedance measurements were carried out at the temperature ranging from 450 K to 600 K, and at the frequency range from 0.1 Hz to 10 MHz. Based on these parameters the electrical properties of the grains and grains boundaries were described. The bulk and grains boundaries resistance of ceramics and the thermal activation energies were determined.
Which tool to distinguish transient alumina from alpha alumina in thermally grown alumina scales?
2005
International audience; Alumina scales constitute excellent protective barriers when they form on alumina-forming steels. If they keep tightly adherent to the underlying substrate, they isolate it from the surrounding aggressive atmosphere at high temperature. The protectiveness of the alumina scale is highly dependant upon its growth mechanism. The nucleation and transformation of transient alumina (mainly g-Al2O3 and y-Al2O3) is known to play an important role on alumina scale formation. It is therefore fundamental to characterise these transient alumina especially during the early stages of the oxidation process. The morphology of the transient alumina was observed by scanning electron m…
An experimental methodology to study polymer crystallization under processing conditions. The influence of high cooling rates
2002
Abstract A new experimental route for investigating polymer crystallization under very high cooling rates (up to 2000°C/s) is described. A complete and exhaustive description of the apparatus employed for preparing thin quenched samples (100– 200 μm thick) is reported, the cooling mechanism and the temperature distribution across sample thickness is also analysed, showing that the final structure is determined only by the thermal history imposed by the fast quench apparatus. Details concerning the characterization techniques used to probe the final structure are reported, including density measurements and wide angle X-ray diffraction patterns. Experimental results concerning isotactic poly…
Experimental and theoretical study to explain the morphology of CaMoO4 crystals
2018
Abstract CaMoO 4 crystals were prepared by a controlled co-precipitation method and processed in a domestic microwave-assisted hydrothermal system with two different surfactants (ethyl 4-dimethylaminobenzoate and 1,2,4,5-benzenetetracarboxylic dianhydride). The corresponding structures were characterized by X-ray diffraction and Rietveld refinement techniques, Fourier transform infrared spectroscopy, ultraviolet–visible absorption spectroscopy, and photoluminescence measurements. Field emission scanning electron microscopy was used to investigate the morphology of the as-synthesized aggregates. The structure, the surface stability of the (001), (112), (100), (110), (101), and (111) surfaces…
The continuous cooling transformation (CCT) as a flexible tool to investigate polymer crystallization under processing conditions
2009
An experimental route for investigating polymer crystallization over a wide range of cooling rates (from 0.01 to 1000◦C/s) and pressures (from 0.1 to 40 MPa) is illustrated, using a method that recalls the approach adopted in metallurgy for studying structure development in metals. Two types of experimental setup were used, namely an apparatus for fast cooling of thin films (100–200 μm thick) at various cooling rates under atmospheric pressure and a device (based on a on-purpose modified injection molding machine) for quenching massive samples (about 1–2 cm3) under hydrostatic pressure fields. In both cases, ex situ characterization experiments were carried out to probe the resulting struct…
Gladius-bearing coleoids from the Upper Cretaceous Lebanese Lagerstätten: diversity, morphology, and phylogenetic implications.
2017
AbstractGladius-bearing coleoids are rare in the fossil record. For the Cretaceous period, these cephalopods are mainly recorded in a few Lagerstätten in Lebanon (Haqel, Hajoula, En Nammoura, and Sahel Aalma). Here, we study 16 specimens of gladius-bearing coleoids from these Upper Cretaceous Lebanese Lagerstätten to investigate their taxonomic diversity. Besides two species that were already reported (Dorateuthis syriacaandGlyphiteuthis libanotica), one new species is identified in the Cenomanian site of Hajoula:Rachiteuthis acutalin. sp., as well as another form ofGlyphiteuthisfrom En Nammoura. Several studied specimens exhibit well-preserved soft-part characters. Among them, we document …
Vergleichende Untersuchungen �ber Morphologie und Histogenese des Seminoms und Disgerminoms
1951
An Hand eingehender morphologisch-histologischer Untersuchungen von Seminom und Disgerminom wird die Verwandtschaft beider Tumoren einer kritischen Stellungnahme unterzogen mit dem Ergebnis: 1. Seminom und Disgerminom sind morphologisch gleichartige Tumoren. 2. Als Mutterzelle mus die noch nicht geschlechtsspezifisch differenzierte Keimzelle aufgefast werden. 3. Seminome und Disgerminome sind keine Teratome, sie sind bestenfalls mit den Teratomen uber eine allen gemeinsame Mutterzelle verwandt.
Entwicklungsmechanische Untersuchungen an Amphibien
1925
Izvilkums no: ''Biologischen Zentralblatt", 45. Bd., 2. Heft, Februar 1925.