Search results for "ELECTRON MICROSCOPY"
showing 10 items of 706 documents
Double-Shell Vesicles, Strings of Vesicles and Filaments Found in Crosslinked Micellar Solutions of Poly(1,2-butadiene)-block-poly(ethylene oxide) Di…
2001
Micellar structures of amphiphilic poly(1,2-butadiene)-block-poly(ethylene oxide) diblock copolymers have been crosslinked in aqueous solution by γ-irradiation. By transmission electron microscopy (TEM) of neganively stained specimen it is shown that the precominant structures present are sopolymer sesicles (which appear to be double latered. These fived vesules are stable with respect to their share and can be transferred from water into a good solvent for blue filbeks, such as tetrahydrofuran, this demonstrating the effectiveness of the crosslinking. In addition to the resicles a small number of flexible cylindrichl/filimented structures sequentially fused vesicles/strings of vesicles and…
Structural Characterization of Zirconia Nanoparticles Prepared by Microwave-Hydrothermal Synthesis
2009
Nanocrystalline zirconia powders have been prepared by microwave-hydrothermal synthesis starting from aqueous solution of ZrOCl2·8H2O. Results of investigations on the aqueous suspension stability of the washed zirconia nanopowders by dynamic light scattering showed that the suspension, constituted by superaggregates of nanoparticles (131 ± 10 nm), was stable up to 15 days. Nanopowders were investigated by means of transmission electron microscopy and small angle x-ray scattering measurements which proved that the zirconia nanopowder is constituted by small primary nanoparticles of ca. 8 nm that agglomerate forming bigger aggregates of 50 ± 1 nm.
Consolidation and protection by nanolime: recent advances for the conservation of the graffiti, Carceri dello Steri Palermo and of the 18th century l…
2014
Abstract Nanolime dispersed in 2-propanol was extensively used for the consolidation of wall paintings. The knowledge of the advances of this methodology dealing with all the possible effects associated with the nanolime new material in conservation is fundamental to assess and improve the technique. In this paper, four different dispersions of Ca(OH) 2 nanoparticles were characterised by Small Angle X-rays Scattering technique (SAXS) and Transmission Electron Microscopy (TEM) in order to achieve information on size, shape, polydispersity, agglomeration, and crystal structure (by SAED patterns) of the particles. Once characterised, the dispersions were tested in two different case studies, …
Estudio Arqueométrico de Maravedís de Felipe IV (1660-1664)
2018
"La presente investigación está fnanciada con el proyecto I+D: “Aplicación de las técnicas nanoelectroquímicas y biotecnologías en el estudio y conservación del CTQ2014-53736-C3 cofnanciado con fondos FEDER adscrito al Programa estatal de fomento de la investigación científca y técnica de excelencia, subprograma estatal de generación del conocimiento, MINECO (2015-2017). Los autores agradecen la colaboración de Dr. José Luis Moya y Manuel Planes, técnicos responsables del Servicio de Microscopía Electrónica de la Universitat Politècnica de València y a Manuel Gozalbes, conservador del Museu de Prehistòria de Valènciapatrimonio en metal” Referencia:"
Effects of tributyltin(IV) chloride on fertilization of Styela plicata (Ascidiacea: Tunicata): II. Scanning and transmission electron microscopy stud…
2003
The morphological aspects of Styela plicata fertilization after treatment with tributyltin(IV) chloride are described by means of scanning and transmission electron microscopy investigations. Alterations have been shown both on female and male gametes; spermatozoa, all the egg envelopes and the mitochondria of the egg cortical cytoplasm are modified in relation to incubation time. As a consequence, the damage to gametes blocks sperm-egg interaction and fertilization does not occur. Copyright © 2003 John Wiley & Sons, Ltd.
Effects of tributyltin(IV) chloride on the gametes and fertilization ofAscidia malaca (Ascidiacea: Tunicata)
2003
Ascidia malaca gametes before fertilization incubated in 10-5 or 10-7 M solutions of tributyltin(IV) chloride, TBTCl, for 3 h appear highly damaged under transmission electron microscopy observation. Also, the fertilization process is affected by the compound: the damaged spermatozoa are present in the vitelline coat and the egg does not cleave. An increase of microbodies, structurally similar to peroxisomes, have been detected in the egg peripheral cytoplasm, probably in relation to their role in alleviating damage to some cellular components. The results have shown that the reproduction of ascidians under unfavourable environmental conditions is prevented. Copyright © 2003 John Wiley &…
The growth of oxide platelets on nickel in pure oxygen. II. Surface analyses and growth mechanism
1993
The structural properties of NiO platelets emerging from a primary oxide layer by oxidation of pretreated nickels in pure oxygen between 650 and 800° C have been investigated in relation with the initial metallic layers and the primary oxide. Surface composition and segregation of impurities were also studied by X-ray photoelectron spectroscopy and Auger electron spectroscopy. Textural properties and structural orientation of both the primary oxide layer and the platelets were analyzed by X-ray diffraction and transmission electron microscopy. Platelets grew along {111} planes, leading to elliptical or semicircular bicrystals. The driving force for the present type of growth originates from…
Initial chemical transport of reducing elements and chemical reactions in oxide cathode base metal
2002
Abstract In the present work, the formation of compounds associated to the diffusion of reducing elements (Mg and Al) to the nickel surface of a one-piece oxide cathode has been studied. Those compounds have been evidenced after the annealing steps at high temperature performed on cathode base metal prior to the emitting coating deposition. Therefore, they form the “initial” interface between the nickel and the coating, in other words, the interface existing at the beginning of cathode life. Extensive analysis to characterize the nickel base prior to coating deposition has been performed by means of scanning electron microscopy (SEM) coupled with energy dispersive X-ray spectroscopy (EDX), …
Diamond nucleation on iridium: local variations of structure and density within the BEN layer
2009
Abstract The diamond nuclei generated by the bias enhanced nucleation (BEN) on iridium are gathered in well defined areas (“domains”). In atomic force microscopy (AFM) measurements they become manifest in a 1 nm downward step. The fine structure of the carbon layer inside and outside these domains has been studied by small spot Auger electron spectroscopy (AES), high resolution transmission electron microscopy (HRTEM), AFM and lateral force microscopy (LFM). The Auger spectra of the carbon KLL peak taken in an ultra high vacuum setup revealed diamond features inside and more graphitic features outside the domains. The comparison with the intensity of the Auger signal originating from the un…
Green composites based on biodegradable polymers and anchovy (Engraulis Encrasicolus) waste suitable for 3D printing applications
2022
Every day large amounts of fish waste are produced and grossly discarded in markets around the world causing environmental and hygiene issue. The use of these scraps for the production of materials with higher added value can definitely contributed to solve this problem. In this work, 10% and 20% of anchovy fishbone powder (EE), obtained by market waste, were microbiological and mechanical tested and subsequently added to polylactic acid (PLA) and to a commercial blend of biodegradable co-polyesters (Mater-Bi®). Rheological characterization suggests the potential printability of all prepared composites filaments. 10% EE filled composites showed outstanding printability. Morphological analys…