Microstructural characterization of Ru-doped NiCoCrAlYTa coupons treated by thermal oxidation

Isothermal oxidation of sintered Ru-doped and undoped Ni-alloy coupons in the range of 1173–1423 K was investigated. To assess the effect of Ruthenium doping, microstructural characterization was performed to compare the samples before and after oxidation treatment at 1173 K. Furthermore, cyclic oxidation tests on the Ru-doped and undoped coupons were carried out in a thermogravimetry apparatus at 1223 and 1323 K. The addition of 0.8 wt.% of Ru in NiCoCrAlYTa powders sintered coupons does not degrade the material’s resistance to oxidation conditions

Chemical Vapor Deposition of Aluminum Oxide Thin Films Using a Low-cost Direct Liquid Injection Delivery System: An Educational Laboratory Experiment

Abstract The chemical vapor deposition is an attractive technique for the growth of thin films and coatings, mainly focused in applications of wear protection, corrosion and microelectronic. This technique has received special attention because allows to deposit thin films and coatings on complex substrates with irregular geometry. The laboratory experiment presented includes a delivery system based on an electro mechanical injector, denominated direct liquid injection, an updated variant of the classical chemical vapor deposition process with the aim of providing a more constant vapor phase for the process. Although it's numerous advantages, the high price for this equipment represents a barrier for the widespread of this technique in academic environments. The accessible materials used for this experiment setup allows building the setup in laboratories and facilities of universities and research centers focused on nanotechnology and materials science. The experiment setup has been successfully build and is used as a compressive hands-on tool to teach undergraduate, master and doctorate students the direct liquid injection chemical vapor deposition technique

Spark Plasma Sintering and Characterization of NiCoCrAlY-Ta Superalloy Powder

In the present study, the spark plasma sintering technique is used to densify commercial alloy NiCoCrAlY-Ta. Such powder was sintered at temperatures ranging between 900 and 1050 °C to yield various microstructures. Full compaction is achieved in a short time and the overall processing duration does not exceed 30 min. Microestructural and porosity evaluation was investigated by using scanning electron microscopy and chemical analysis. Two phases, β and γ, were identified in sintered microstructure by XR-diffraction. Micro Vickers tests were carried out on the sintered specimens, the resultant properties at room temperature are very promising whereas major hardness resistance was obtained at 1000 °C

Identification of protein expressed by aortic stenosis valves in the search for novel biomarkers

Comunicaciones a congreso

Primer registro de la comadreja (Mustela frenata) en el estado de Campeche, México

In this paper, we report three different records of the long tail weasel (Mustela frenata) using camera traps in the western portion of Campeche; thus confirming the presence of the species in this Mexican state

1H-NMR Urinary Metabolic Profile, A Promising Tool for the Management of Infants with Human Cytomegalovirus-Infection

Abstract: Congenital human cytomegalovirus (HCMV) infection is the most common mother-to-child transmitted infection in the developed world. Certain aspects of its management remain a challenge. Urinary metabolic profiling is a promising tool for use in pediatric conditions. The aim of this study was to investigate the urinary metabolic profile in HCMV-infected infants and controls during acute care hospitalization. Urine samples were collected from 53 patients at five hospitals participating in the Spanish congenital HCMV registry. Thirty-one cases of HCMV infection and 22 uninfected controls were included. Proton nuclear magnetic resonance (1H-NMR) spectra were obtained using NOESYPR1D pulse sequence. The dataset underwent orthogonal projection on latent structures discriminant analysis to identify candidate variables affecting the urinary metabolome: HCMV infection, type of infection, sex, chronological age, gestational age, type of delivery, twins, and diet. Statistically significant discriminative models were obtained only for HCMV infection (p = 0.03) and chronological age (p < 0.01). No significant differences in the metabolomic profile were found between congenital and postnatal HCMV infection. When the HCMV-infected group was analyzed according to chronological age, a statistically significant model was obtained only in the neonatal group (p = 0.01), with the differentiating metabolites being betaine, glycine, alanine, and dimethylamine. Despite the considerable variation in urinary metabolic profiles in a real-life setting, clinical application of metabolomics to the study of HCMV infection seems feasible

REVISIÓN DEL ESTADO DEL ARTE DEL EFECTO DE PROCESOS DE FABRICACIÓN SOBRE ESFUERZOS EN COMPONENTES DE ALUMINIO

Conocer el efecto de los parámetros de maquinado y soldadura sobre los esfuerzos residuales en diferentes componentes de aleaciones de aluminio, realizando una revisión de la literatura de las técnicas de evaluación de los esfuerzos residuales reportadas en artículos científicos y tesis de posgrado. Con el fin de seleccionar una de estas técnicas para evaluar los esfuerzos residuales en un pistón automotriz de aleación de aluminio-silicio.Palabra(s) Clave(s): agujero ciego, esfuerzos residuales, indentación colineal, método de elementos finitos (MEF), rayos-X