Search results for "morphology"
showing 10 items of 1425 documents
Porous titanium for biomedical applications : an experimental study on rabbits
2010
Made available in DSpace on 2013-08-12T18:44:08Z (GMT). No. of bitstreams: 0 Previous issue date: 2010-03-01 Made available in DSpace on 2013-09-30T18:34:10Z (GMT). No. of bitstreams: 0 Previous issue date: 2010-03-01 Submitted by Vitor Silverio Rodrigues (vitorsrodrigues@reitoria.unesp.br) on 2014-05-20T14:04:32Z No. of bitstreams: 0 Made available in DSpace on 2014-05-20T14:04:32Z (GMT). No. of bitstreams: 0 Previous issue date: 2010-03-01 Objective: The aim of this study was to carry out an in vivo assessment of bone ingrowth in two different types of porous titanium -the first being completely porous, and the second with a porous surface and dense nucleus, manufactured by powder metallu…
Morphology and Band Structure of Orthorhombic PbS Nanoplatelets: An Indirect Band Gap Material
2021
PbS quantum dots and nanoplatelets (NPLs) are of enormous interest in the development of optoelectronic devices. However, some important aspects of their nature remain unclear. Recent studies have revealed that colloidal PbS NPLs may depart from the rock-salt crystal structure of bulk and form an orthorhombic (Pnma) modification instead. To gain insight into the implications of such a change over the optoelectronic properties, we have synthesized orthorhombic PbS NPLs and determined the lattice parameters by means of selected area electron diffraction measurements. We have then calculated the associated band structure using density functional theory with Perdew–Burke–Ernzerhof functional fo…
Template-synthesized nanostructure morphology influenced by building block structure
2011
We report the synthesis and characterization of a series of nanostructures and determine whether several distinct types of building blocks can be fashioned into linear nanostructures using hard-templates and electrochemical methods. We determine the aspects of molecular structure that influence morphology and propose a mechanism whereby morphology changes as a function of building block. We show how hydrophobic side-chains, such as 3-hexyl and 3-(2-ethyl)hexyl, can be used to prepare nanostructures with a geometry that is different from the shape of the template from which they derive. These nanostructures exhibit collapsed, nonlinear, and nonrigid shapes as observed by SEM and TEM. Hydroph…
Highly luminescent perovskite–aluminum oxide composites
2015
In this communication we report on the preparation of CH3NH3PbBr3 perovskite/Al2O3 nanoparticle composites in a thin film configuration and demonstrate their high photoluminescence quantum yield. The composite material is solution-processed at low temperature, using stable alumina nanoparticle dispersions. There is a large influence of the alumina nanoparticle concentration on the perovskite morphology and on its photoluminescence.
Mechanochemical synthesis of inorganic halide perovskites: evolution of phase-purity, morphology, and photoluminescence
2019
Dry mechanochemical ball-milling of halide precursor salts is a promising route for the synthesis of high-purity halide perovskites in a fast and solvent-free manner. However, there is a lack of information on the process mechanisms, kinetics, and possible side-effects. Here, we investigated in detail the mechanochemical synthesis of fully-inorganic CsPbBr3 by ball-milling of stoichiometric CsBr and PbBr2. Detailed structural, morphological and optical analyses reveal several beneficial and detrimental effects of milling as a function of time. Three stages are identified during the process: (i) at short milling times (t < 5 min) different ternary compounds are formed, including stoichiometr…
Emulsion-based synthesis of PLGA-microspheres for the in vitro expansion of porcine chondrocytes.
2007
Abstract The in vitro cell expansion of autologous chondrocytes is of high interest in regenerative medicine since these cells can be used to treat joint cartilage defects. In order to preserve chondrocyte phenotype, while optimizing adhesion on microspheres, several processing parameters for the microsphere synthesis were varied. In this study three different polylactide-co-glycolides were used with differing lactide–glycolide ratios (85:15 and 50:50) and differing inherent viscosities. An emulsion route was established, where the polymer was dissolved in chloroform and then injected into a stirred polyvinyl alcohol–water solution at different polymer concentrations and different stirring …
The influence of the raw material and production method on the morphology, microstructure, chemical and phase composition of tetrabasic lead sulfate …
1992
Abstract Tetrabasic lead sulfate (4BS) produced by two different methods (solution and paste) and from two different raw materials (tetragonal PbO and leady oxide) were charaterized by different analytical techniques. The techniques applied were wet-chemical methods, scanning electron microscopy, transmission electron microscopy and X-ray powder diffraction. The preparation method was observed to be the most decisive factor influencing the structure and the morphology of the 4BS pastes in this study.
The Isoetes longissima complex (Isoetaceae) in Italy: observations on the morphology of spores and leaves, and taxonomic implications
2014
The morphological variability of the Isoetes longissima complex in Italy has been analyzed, on the basis of selected herbarium specimens. Observations were made on spore ornamentation and size, number of leaves per plant and maximum leaf length, velum extension and alae width in the basal portion of leaves. The first count of chromosome number on plants from Italy is also made. On the basis of our observations, the five taxa here considered are attributed to two taxa, treated at the species level as follows: I. longissima (incl. I. velata and I. velata [unranked] sicula), and I. tiguliana (incl. I. dubia). Italian distribution of these species is also given.
The reaction of Ciona intestinalis L. (Tunicata) to subcuticular erythrocyte and protein injection
1981
Abstract Ciona intestinalis reacts to subcuticular injection of corpuscular or soluble antigens producing a capsule around the foreign material. The morphology and the histochemical composition of the injected area was examined. The time sequence of the reaction is characterized by a heightened non-specific secondary response.
Ploidy levels in Citrus clementine affects leaf morphology, stomatal density and water content
2013
The objective of the present study was to understand the relationship among leaf morphology, stomatal characteristics and water relations in triploids generated through anther culture and their counterpart diploid plant of C. clementina. Triploid plants possessed small and narrow leaves as compared to diploid plant as evident by less leaf length, leaf width and leaf area. By contrast, the leaf index was observed to be more in triploids than haploid ones. Flow cytometric analysis re-confirmed the ploidy levels of heterozygous plant Hd as diploid and the ploidy of Th1, Th2, Th3 and Th4 plants as triploids. A positive relation was found between ploidy level and stomatal guard cell length and w…