45 research outputs found
Estudio de Materiales Nanoestructurados por Metalurgia de Polvos del Ternario Zn-Al-Ag
In this work one presents the study realized to the compound materials: a) Zn77.0-Al22.0-Ag1.0 (wt. %) [Ternary Alloy], b) Zn77.0-Al22.0-Ag-1.0 (wt. %) [Compound Material 1] reinforced with 5 % of NaCl, and c) Al77.0-Zn22.0-Ag1.0 (wt. %)/Si [compound Material 2], the materials were incorporated by means of the alloyed mechanic in a time of grinding of 7 hours. The microstructural characterization was realized by means of: a) Diffraction of beams-X (DRX), b) Scanning Electronic Microscopy (SEM) and c) Microhardness Vickers (HV). The aim of this work was to study the effect of the microstructure and the hardness of a materials composed bases zinc and his comparison with a ternary alloy. Materials were obtained nanostructure by sizes of crystal in the ternary alloy of 94nm, and for the compound materials 1 and 2, 116 and 121 nm respectively. The values of hardness obtained for three systems have direct relation with the size of crystal. The image obtained to SEM at 7 hours of grinding suggests that the ternary alloy presents in the morphology bigger agglomerated particles and the compound material 2 particles small flakes. The results suggest that porous materials were obtained in three studied systems. Keywords: Mechanical alloy, Metallurgy of powders, Nanocomposite, Reinforcement with particles
Diseño protótipo de ejercitador para apoyo en pacientes post covid-19
In breathing problems, it is importan to provide a continuous and accurate flow of oxigen, in this study a thorough investigation of the sequelae that can presente a post Covid patient. The results shown are 3D prints of the prototyped design of the air exerciser through the Computer Assistent Design CAD software, in order to search for innovations in ergonomics and its correct funtionality, as well as to monitor, measure and control the main variables such as air flow and indicate time. A particular goal is to generate new statistical information based on the use of the alarms that will be programmed, with the purpose that the patient can have a prompt rehabilitation and above all a better way of breathing. Among the main features of the equipment is that it is portable, lightweight, compact, ergonomic and has the ability to communicate wirelessly trough a standard port such as Bluetooth and this can be connected to smartphone through an application that will be developed specifically for the device, the application will be free and can be downloaded from a public website, just by registering.En problemas de respiración es importante suministrar un flujo continuo y preciso de oxígeno, en este estudio se realiza una profunda investigación de las secuelas que puede presentar un paciente post Covid. Los resultados mostrados son impresiones en 3D del diseño prototipo de ejercitado de aire a través del software Diseño Asistido por Computadora CAD, con el objeto de buscar innovaciones en ergonomía y su correcta funcionabilidad, así como monitorear, medir y controlar las principales variables como el flujo de aire y tiempo indicado. Un objetivo particular es generar nueva información estadística con base en uso de las alarmas que se vayan a programar, con el propósito que el paciente pueda tener una pronta rehabilitación y sobre todo una mejor forma regular de su respiración. Dentro de las principales características del equipo es que sea portátil, ligero, compacto, ergonómico y que tenga la capacidad de comunicación inalámbrica por medio de un puerto estándar como el bluetooth y de esta forma se pueda conectar a un teléfono inteligente mediante una aplicación que se desarrollará específicamente para este dispositivo, dicha aplicación será gratis y se podrá descargar desde un sitio web público, bastara solo con registrarse
Los Procesos Constructivos de Vivienda Vertical en serie, un desafío a los planes de Desarrollo Urbano y Territorial, en el Área Metropolitana de Guadalajara
The subdivisions in the Metropolitan Area of Guadalajara (AMG) of restricted access have become a model of segregated spaces in the peripheries of the cities. These models of development have undergone significant transformations in the urban basins of the mexican territory, since they are housing developments with greater backwardnees, causing a greater fragmentation of public spaces, favoring the coexistence of a polarized society. The paradigm shift seen from urbanization in high-risk áreas, is to incorporate key elements, such as architectural and technological innovations that are able to reduce or decrease the amount of energy produced by the vast majority in the construction of vertical housing. The goal then is to determine the flooding that occurs in the Lomas of Mirador neighborhood by means of probabilistic and statistical models, as well as to identify by means topographic cartography the flood plains that occur in the hydrographic basin of the valley zone of the municipality of Tlajomulco of Zuñiga, the results obtained were the peak flows for return periods Tr up to 100 years before and after the urbanization, it is concluded that a combination of hydraulic Works presentes na alterntive solution to the problems mentioned above.Los fraccionamientos en el Área Metropolitana de Guadalajara (AMG) de acceso restringido se han convertido en un modelo de espacios segregados en las periferias de las ciudades. Dichos modelos de desarrollo han sufrido grandes transformaciones significativas en las cuecas urbanas del territorio mexicano, ya que se trata de viviendas con mayores rezagos, ocasionando una mayor fragmentación de espacios públicos, propiciando la coexistencia de una sociedad polarizada. El cambio de paradigma visto desde la urbanización en zonas de alto riesgo, es incorporar elementos clave, tales como innovaciones arquitectónicas y tecnológicas que sean capaces de abatir o disminuir la cantidad de energía producidos por la gran mayoría en la construcción de vivienda vertical. El objetivo entonces es determinar la magnitud de los escurrimientos pluviales en la parte baja de la colonia Lomas del Mirador, así como los hidrogramas antes y después de la urbanización mediante modelos probabilísticos y estadísticos que se producen en la cuenca hidrográfica de la zona valles del municipio de Tlajomulco de Zúñiga, los resultados obtenidos fueron los gastos picos para periodos de retorno Tr hasta 100 años antes y después de la urbanización, se concluye que una combinación de obras hidráulicas presenta una alternativa de solución a los problemas antes citados
Synthetic Geopolymers for Controlled Delivery of Oxycodone: Adjustable and Nanostructured Porosity Enables Tunable and Sustained Drug Release
In this article we for the first time present a fully synthetic mesoporous geopolymer drug carrier for controlled release of opioids. Nanoparticulate precursor powders with different Al/Si-ratios were synthesized by a sol-gel route and used in the preparation of different geopolymers, which could be structurally tailored by adjusting the Al/Si-ratio and the curing temperatures. In particular, it was shown that the pore sizes of the geopolymers decreased with increasing Al/Si ratio and that completely mesoporous geopolymers could be produced from precursor particles with the Al/Si ratio 2∶1. The mesoporosity was shown to be associated with a sustained and linear in vitro release profile of the opioid oxycodone. A clinically relevant release period of about 12 h was obtained by adjusting the size of the pellets. The easily fabricated and tunable geopolymers presented in this study constitute a novel approach in the development of controlled release formulations, not only for opioids, but whenever the clinical indication is best treated with a constant supply of drugs and when the mechanical stability of the delivery vehicle is crucial
Transparent nanocrystalline yttria-stabilized-zirconia calvarium prosthesis
UnlabelledLaser-based diagnostics and therapeutics show promise for many neurological disorders. However, the poor transparency of cranial bone (calvaria) limits the spatial resolution and interaction depth that can be achieved, thus constraining opportunity in this regard. Herein, we report preliminary results from efforts seeking to address this limitation through use of novel transparent cranial implants made from nanocrystalline yttria-stabilized zirconia (nc-YSZ). Using optical coherence tomography (OCT) imaging of underlying brain in an acute murine model, we show that signal strength is improved when imaging through nc-YSZ implants relative to native cranium. As such, this provides initial evidence supporting the feasibility of nc-YSZ as a transparent cranial implant material. Furthermore, it represents a crucial first step towards realization of an innovative new concept we are developing, which seeks to eventually provide a clinically-viable means for optically accessing the brain, on-demand, over large areas, and on a chronically-recurring basis, without need for repeated craniectomies.From the clinical editorIn this study, transparent nanocrystalline yttria-stabilized-zirconia is used as an experimental "cranium prosthesis" material, enabling the replacement of segments of cranial bone with a material that allows for optical access to the brain on a recurrent basis using optical imaging methods such as OCT
The effect of Ag addition on the corrosion of Zn-22wt%Al alloys
A new Zn-Al-Ag alloy (ZINAG) with mechanical superplastic properties has been developed. In this work four of the Zn-22wt%Al eutectoid alloy doped with between 0.5 to 4.24 wt% Ag have been studied. The superplastic behavior can be explained as a consequence of the fine grain distribution induced during the deformation process. Here the corrosion resistance of these alloys was studied by means of potentiodynamic polarization and measurements of the temporal evolution of the corrosion potential, in a 0.5 M NaCl solution, The corrosion products in the sample surface were analyzed by Rutherford Backscattering Spectrometry (RBS), X-Ray Photoelectron Spectroscopy (XPS) and Auger Electron Spectroscopy (AES). It was found that the corroded surface had lost more Zn than Al. The surface was examined by SEM and it was seen that the corrosion products adhered to the surface cracks. It was found that the alloy with 2.12 wt% concentration of Ag had the best corrosion resistance in the electrolyte used, but no clear tendency with the Ag concentration was found. � 2003 Materials Research Society
Microstructural analysis of a1-mg-si-zn alloy
As a part of an overall effort to develop a new A1-alloy appropriated for structural applications, a characterization research was directed towards the development of microstructure and their relationship with heat treatment. The A1-Mg-Si-Zn was chose for that purpose due to the presence of precipitates in α-A1 matrix and at grain boundaries, capable to get an excellent relationship between hardness and mechanical resistance. With regards to microstructure, this was characterized in the as-cast and as-aged condition. This treatment was carried out in two stages, the first one at 450ºC during 3 hr which correspond to homogenization treatment and the second one, the ageing treatment at 160 ºC 1hr. Results of microstructure characterization in the ascast ingots showed the α-A1 dendrites, and in addition the presence of a binary eutectic and particles of Mg₇Zn₃ type in interdendritic regions. The eutectic and particles were modified by the aged treatment. Transmission electron microscopic observations carried out in specimens with and without heat treatments showed a uniform distribution of precipitates with different morphologies like cubic, spherical and platelet; in the matrix, which were no detected during the scanning electron microscope observations
MIicrostructural analysis of A1-Mg-Si-Zn Alloy
As a part of an overall effort to develop a new Alalloy appropriated for structural applications, a characterization research was directed towards the development of microstructure and their relationship with heat treatment. The AlMgSiZn was chose for that purpose due to the presence of precipitates inaAl matrix and at grain boundaries, capable to get an excellent relationship between hardness and mechanical resistance. With regards to microstructure, this was characterized in the ascast and asaged condition. This treatment was carried out in two stages, the first one at 450ºC during 3 hr which correspond to homogenization treatment and the second one, the ageing treatment at 160 ºC 1hr. Results of microstructure characterization in the ascast ingots showed theaAl dendrites, and in addition the presence of a binary eutectic and particles of Mg7Zn3 type in interdendritic regions. The eutectic and particles were modified by the aged treatment. Transmission electron microscopic observations carried out in specimens with and without heat treatments showed a uniform distribution of precipitates with different morphologies like cubic, spherical and platelet; in the matrix, which were no detected during the scanning electron microscope observationsEn un esfuerzo por desarrollar una nueva aleación con aplicación estructural, se ha desarrollado una aleación base Aluminio aleada con magnesio, silicio y zinc. La investigación pretende correlacionar la microestructura y con el tratamiento térmico. La aleación A1-Mg-Si-Zn, fue elegida para ese propósito debido a la presencia de precipitados tanto en la matriz de la Al, como en los límites de grano, los cuales permiten una excelente relación entre la dureza y la resistencia mecánica. En lo que respecta a la microestructura, esta fue caracterizada bajo condición de colada y después de ser tratada térmicamente por envejecimiento. Este tratamiento fue realizado en dos etapas, la primera a 450ºC durante 3 horas que corresponde al tratamiento de homogeneización; y la segunda al proceso de envejecimiento artificial llevado a cabo a 160ºC durante 1hr. Los resultados indican la presencia de dendritas de a-A1, además un eutéctico binario y partículas de Mg7Zn3 adentro de las regiones interdendríticas. El eutéctico y las partículas fueron modificados por el tratamiento de envejecido. Las observaciones realizadas con el microscopio electrónico de transmisión en especímenes con y sin tratamientos térmicos, demostraron una distribución uniforme de precipitados con diversas morfologías, tales como cúbico, esférico y plaqueta; para la matriz de α-A1,los cuales no fueron detectados durante las observaciones en el microscopio electrónico de barrid