La calorimetría diferencial de barrido y su aplicación a la Ciencia de Materiales

Se pone de manifiesto la idoneidad de la técnica de calorimetría diferencial de barrido para la caracterización de materiales. Se presentan ejemplos específicos de aplicación de dicha técnica en el estudio de los fenómenos ligados a la transición vitrea y cinética de cristalización de vidrios calcogenuros y metálicos así como en el estudio de la reordenación de fases desordenadas metastables

Biodegradation and Mechanical Integrity of Magnesium and Magnesium Alloys Suitable for Implants

This book chapter deals with the fundamental aspects of corrosion of magnesium based alloys in bodily fluids and reviews the various techniques that can be used to tune their degradation rate. The time-dependent evolution of their mechanical properties during the biodegradation process is also outlined

Acromegàlia : test sobre el seu impacte en la qualitat de vida

L'acromegàlia, denominada també popularment gegantisme, és una malaltia que causa un creixement anormal en algunes parts i òrgans del cos. Per valorar-ne l'impacte sobre la qualitat de vida de les persones que la pateixen, especialistes de diferents hospitals espanyols han desenvolupat un senzill test: l'AcroQol.La acromegalia, también denominada popularmente gigantismo, es una enfermedad que causa un crecimiento anormal en algunas partes y órganos del cuerpo. Para valorar su impacto sobre la calidad de vida de las personas que la padecen, especialistas de diferentes hospitales españoles han desarrollado un sencillo test, denominado AcroQol

Using exchange bias to extend the temperature range of square loop behavior in [Pt/Co] multilayers with perpendicular anisotropy

This article may be downloaded for personal use only. Any other use requires prior permission of the author and the American Institute of Physics.The temperature dependence of the magnetic properties of [Pt/Co]multilayers (ML), exhibiting perpendicular anisotropy, with and without exchange biasing with an antiferromagnet(AFM) has been investigated. Upon heating, a loss of the out-of-plane anisotropy and, consequently, of the remanence to saturation ratio is observed in these systems. However, such effect occurs at higher temperatures in the [Pt/Co] ML exchange coupled to the AFM than for the unbiased ML. This is attributed to the additional anisotropy induced to the ML by the ferromagnetic-antiferromagnetic exchange coupling

High-coercivity ultralight transparent magnets

This article may be downloaded for personal use only. Any other use requires prior permission of the author and the American Institute of Physics.Magnetic silica-aerogel composites have been synthesized by dispersing hard magnetic Nd2Fe14B particles in a sol during a fast sol-gel process and subsequently supercritically drying the resulting gels. The composites are found to retain most of the outstanding properties of their constituents: the large coercivity and moderate remanence of the magnetic powders and the transparency and low density of silica aerogels. Moreover, aerogels synthesized in the presence of a magnetic field exhibit the alignment of the particles, forming needle-like structures along the direction of the applied magnetic field, which results in optical and magnetic anisotropies. Due to their unique combination of properties, these types of materials may be appealing for magneto-optics and magnetic actuator applications

Localized electrochemical deposition of porous Cu-Ni microcolumns: insights into the growth mechanisms and the mechanical performance

Cu-rich Cu-Ni alloy microcolumns (11-35 at% Ni) with large porosity degree were grown by localized electrochemical deposition (LECD) at voltages of 6.5 and 7.0 V. In turn, conventional electrodeposition was used to deposit fully-compact Cu-Ni films with analogous Ni/Cu ratios from a similar citrate-containing electrolytic solution. The localized supply rate of the predominant Cu(II) and Ni(II) electroactive species in the LECD microregion was calculated assuming both large and small concentration gradients. A shortage of Cu(II) at the cathode surface is mainly responsible for the development of porosity in the microcolumns, which directly affects mechanical performance, specifically nanoindentation hardness and Young's modulus. From nanoindentation experiments, a relative microcolumn density ranging between 14 and 20% was determined. These values indicate the current efficiency of the LECD process and can be used to calculate the consumption rates associated with metal cation electroreduction

Tuneable magnetic patterning of paramagnetic Fe60Al40 (at. %) by consecutive ion irradiation through pre-lithographed shadow masks

This article may be downloaded for personal use only. Any other use requires prior permission of the author and the American Institute of Physics.Arrays of ferromagnetic circular dots (with diameters ranging from 225 to 420 nm) have been prepared at the surface of atomically ordered paramagnetic Fe60Al40 (at. %) sheets by means of ion irradiation through prelithographed poly(methyl methacrylate) (PMMA) masks. The cumulative effects of consecutive ion irradiation (using Ar+ ions at 1.2 × 1014 ions/cm2 with 10, 13, 16, 19 and 22 keV incident energies) on the properties of the patterned dots have been investigated. A progressive increase in the overall magneto-optical Kerr signal is observed for increasingly larger irradiation energies, an effect which is ascribed to accumulation of atomic disorder. Conversely, the coercivity, HC, shows a maximum after irradiating at 16-19 keV and it decreases for larger irradiation energies. Such a decrease in HC is ascribed to the formation of vortex states during magnetization reversal, in agreement with results obtained from micromagnetic simulations. At the same time, the PMMA layer, with an initial thickness of 90 nm, becomes progressively thinned during the successive irradiation processes. After irradiation at 22 keV, the remaining PMMA layer is too thin to stop the incoming ions and, consequently, ferromagnetism starts to be generated underneath the nominally masked areas. These experimental results are in agreement with calculations using the Monte-Carlo simulation Stopping Range of Ions in Matter software, which show that for exceedingly thin PMMA layers Ar+ ions can reach the Fe60Al40 layer despite the presence of the mask

Vaccines as alternatives to antibiotics for food producing animals. Part 2:new approaches and potential solutions

Vaccines and other alternative products are central to the future success of animal agriculture because they can help minimize the need for antibiotics by preventing and controlling infectious diseases in animal populations. To assess scientific advancements related to alternatives to antibiotics and provide actionable strategies to support their development, the United States Department of Agriculture, with support from the World Organisation for Animal Health, organized the second International Symposium on Alternatives to Antibiotics. It focused on six key areas: vaccines; microbial-derived products; non-nutritive phytochemicals; immune-related products; chemicals, enzymes, and innovative drugs; and regulatory pathways to enable the development and licensure of alternatives to antibiotics. This article, the second part in a two-part series, highlights new approaches and potential solutions for the development of vaccines as alternatives to antibiotics in food producing animals; opportunities, challenges and needs for the development of such vaccines are discussed in the first part of this series. As discussed in part 1 of this manuscript, many current vaccines fall short of ideal vaccines in one or more respects. Promising breakthroughs to overcome these limitations include new biotechnology techniques, new oral vaccine approaches, novel adjuvants, new delivery strategies based on bacterial spores, and live recombinant vectors; they also include new vaccination strategies in-ovo, and strategies that simultaneously protect against multiple pathogens. However, translating this research into commercial vaccines that effectively reduce the need for antibiotics will require close collaboration among stakeholders, for instance through public–private partnerships. Targeted research and development investments and concerted efforts by all affected are needed to realize the potential of vaccines to improve animal health, safeguard agricultural productivity, and reduce antibiotic consumption and resulting resistance risks

White-light photoluminescence and photoactivation in cadmium sulfide embedded in mesoporous silicon dioxide templates studied by confocal laser scanning microscopy

This is the author's version of a work that was accepted for publication in Journal of colloid and interface science. Changes resulting from the publishing process, such as peer review, editing, corrections, structural formatting, and other quality control mechanisms may not be reflected in this document. Changes may have been made to this work since it was submitted for publication. A definitive version was subsequently published in Journal of colloid and interface science, [147, 1, (2013)] DOI10.1016/j.jcis.2013.06.022)SBA-15 and SBA-16 silica templates have been infiltrated with CdS by means of nanocasting using a hybrid precursor. The morphology and structure of both the SiO2@CdS nanocomposites and the silica-free CdS replicas have been characterized. The three-dimensional nanocrystalline CdS networks embedded in SBA-15 and SBA-16 silica templates exhibit broad photoluminescence (PL) spectra over the entire visible range, together with enhanced PL intensity compared to silica-free CdS replicas. These effects result from the role silica plays in passivating the surface of the CdS mesostructures. Furthermore, photoactivation is eventually observed during continuous illumination because of both structural and chemical surface odifications. Owing to this combination of properties, these materials could be appealing for solid-state lighting, where ultra-bright near-white PL emission is indispensable