336 research outputs found
Optimización del proceso industrial de fabricación e instalación de cortinas metálicas enrollables en la empresa cortinas de Guatemala S.A.
Optimizar el proceso industrial de fabricación e instalación de cortinas metálicas enrollables para incrementar la productividad, así implementar los cambios planteados en la reestructuración y elaborar un manual de procedimientos para ser utilizado en procesos de inducción de personal de nuevo ingreso a la empresa
Defect structure in nanoalloys
The defect structure of bimetallic nanoparticles differs from that of particles made of a single atomic species. Using high resolution TEM imaging along with molecular dynamics simulations, it is possible to investigate the nature and features of these defects. The definition of a local order parameter allows one to locate regions with different kinds of stacking on the simulated nanoparticles and thus to make a direct comparison with the experimental observations
Signal-to-noise ratio evaluation in resonant ring metamaterial lenses for MRI applications
In this paper, we present a method for the evaluation of the signalto- noise ratio in magnetic resonance imaging (MRI) coils loaded with resonant ring metamaterial lenses, in the presence of a conducting phantom resembling human tissue. The method accounts for the effects of the discrete and finite structure of the metamaterial. Numerical computations are validated with experimental results, including laboratory measurements and MRI experiments.Ministerio de Ciencia e Innovación CSD2008-00066 y TEC2010- 16948Junta de Andalucía TIC-0623
Structural transformation of tungsten oxide nanourchins into IF–WS2 nanoparticles: an aberration corrected STEM study
IF–WS2 nanoparticles synthesized starting from tungsten oxide nanourchins have been investigated by using aberration corrected scanning transmission electron microscopy (Cs-STEM). The synthesis process produced IF–WS2 nanoparticles of two different and well differentiated ranges of size. High resolution HAADF–STEM images and their comparison with simulated STEM micrographs reveal the predominance of stacking of the type 1T close to the border of the structure; the observation of this kind of stacking, observed previously in IF–MoS2 but never reported before in the case of the IF–WS2 nanostructures, adds a new dimension to the existing understanding of structure and stacking in the
case of the nanostructures of transition metal chalcogenide
Presence and Relevance of Emerging Microorganisms in Clinical Genitourinary Samples
The following supporting information can be downloaded at:
https://www.mdpi.com/article/10.3390/microorganisms11040915/s1Abstract: Microorganisms responsible for genitourinary infections increasingly include species other
than conventional etiological agents that are of clinical and pathogenic relevance and therapeutic
interest. This cross-sectional descriptive study selected samples from clinical genitourinary episodes
between January 2016 and December 2019 in which emerging microbiological agents were detected.
The patients’ epidemiological characteristics, clinical presentation, antibiotic treatment, and outcome
were studied to identify their pathogenic role. The emerging microorganisms most frequently
detected in urinary tract infections were Streptococcus bovis (58.5%) and Gardnerella spp. (23.6%) in
females and S. bovis (32.3%), Aerococcus urinae (18.6%), and Corynebacterium spp. (16.9%) in males,
while the most frequently detected in genital infections were S. viridans (36.4%) in females and
C. glucuronolyticum (32.2%) and Gardnerella spp. (35.6%) in males. All cases in female children were
produced by S. bovis. Symptomatic episodes were more frequent with Aerococcus spp. and S. bovis and
the presence of leukocytosis more frequent with Aerococcus spp. Quinolones and doxycycline were
most often prescribed antibiotics for genital infections and quinolones and amoxicillin-clavulanic
acid for urinary infections. Urinary infection by Aerococcus spp. was more frequent in males of
advanced age, Corynebacterium spp. was more frequent in permanent vesical catheter carriers, and
episodes of asymptomatic bacteriuria by Gardnerella spp. were more frequent in patients with kidney
transplant and chronic consumers of corticosteroid therapy. Lactobacillus spp. should be considered in
urinary infections of patients of advanced age and with a previous antibiotic load. Genital infection
by Gardnerella spp. was significantly associated with a history of risky sexual relations
Highly size-controlled synthesis of Au/Pd nanoparticles by inert-gas condensation
Gold/Palladium nanoparticles were fabricated by inert-gas condensation on a sputtering reactor. With this method, by controlling both the atmosphere on the condensation chamber and the magnetron power, it was possible to produce nanoparticles with a high degree of monodispersity in size. The structure and size of the Au/Pd nanoparticles were determined by mass spectroscopy, and confirmed by atomic force microscopy and electron transmission microscopy measurements. The chemical composition was analyzed by X-ray microanalysis. From these measurements we confirmed that with the sputtering technique we are able to produce particles of 1, 3, and 5 nm on size, depending on the choice of the synthesis conditions. From TEM measurements made both in the regular HREM, as well as in STEM-HAADF mode, we found that the particles are icosahedral in shape, and the micrographs show no evidence of a core-shell structure, in contrast to what is observed in the case of nanoparticles prepared by chemical synthesis
The Co–Au interface in bimetallic nanoparticles: a high resolution STEM study
We report the formation of Au/Co nanoparticles and their characterization by aberration (Cs) corrected scanning transmission electron microscopy (STEM). The nanoparticles were synthesized by inert gas condensation, forming initially core-shell and bimetallic crystals. However, after thermal treatment at normal atmospheric conditions, the Co nanoparticles changed their morphology into a fine layer forming a perfect interface with the gold. The ordering of the zone rich in Co presents a fcc arrangement matching the gold lattice. The atomic analysis on the interface and the comparison of the STEM images with numerical simulations corroborated the atomic substitution of gold by cobalt
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