Nonlinear Classical Elasticity Model for Materials with Fluid and Matrix Phases

Materials with fluid and matrix phases present different acoustic responses in each phase. While longitudinal waves propagate in both phases, shear waves do it only through the solid matrix. Longitudinal waves are mainly described by volumetric propagation and shear waves by deviatoric processes. In the case of nonlinear propagation cross effects occur between both components. This paper presents a new classical nonlinear model proposing a constitutive equation that separates volumetric and deviatoric effects. Four nonlinear constants of third order are defined. The formulation is compared to constitutive equations with Landau constants for weakly elasticity and both types of nonlinear constants related. Some reinterpretation of the Landau's constants arises in terms of parallel or cross nonlinear effects between volumetric and deviatoric components.Ministry of Education [Grant nos. DPI2014-51870-R, DPI2017-85359-R, and UNGR15-CE-3664]Ministry of Health [DTS15/00093 and PI16/00339]Junta de Andalucía [PIN-0030-2017 and PI0107-2017 projects]University of Granada [PP2017- PIP2019

Proyecto de ejecución de nave industrial con oficinas

Proyecto de ejecución de nave industrial con oficinas. El proyecto desarrolla la construcción de un edificio de tipo industrial destinado a los usos de venta-exposición de materiales de construcción y de almacenamiento de los productos comercializados, junto con zonas para el uso de oficinas. Características: Diseño de edificio industrial aislado en función de la legislación urbanística vigente del municipio de Alfaro (La Rioja). Diseño y cálculo de la estructura. Definición de los cerramientos. Diseño y cálculo de las instalaciones. Elaboración de mediciones y presupuesto

Vibraciones y Oscilaciones Lineales

Se presentan unos contenidos básicos sobre vibraciones y oscilaciones en sistemas de uno y múltiples grados de libertad. El contenido se ajusta a las dos últimas semanas de la asignatura "Mecánica para Ingenieros" del Grado en Ingeniería Civil de la Universidad de Granada

Numerical Modelling of Magnetic Nanoparticle Behavior in an Alternating Magnetic Field Based on Multiphysics Coupling

In magnetic nanoparticle hyperthermia, the magnetic nanoparticles (MNPs) start oscilla- tions when they are exposed to an alternating magnetic field, which may generate ultra- sound waves. These resulting oscillations of nanoparticles can lead to the movement of drug carrier liposomes. In this study, a multiphysics coupling model of magnetic nanoparticle behavior in an alternating magnetic field was developed, implementing solid mechanics compliance parameters and piezomagnetic coupling matrices. A detailed sensitivity study was conducted to to examine the effects of size and elastic modulus of MNPs, distribution and distance between two MNPs, elasticity and viscosity of the glycerol medium and mesh element sizes on the output displacement signals of MNPs. The results indicated that mag- netic nanoparticles undergo some displacements when they are exposed to an alternating magnetic field. These oscillations may generate ultrasound waves, though the amount of displacement for each nanoparticle is negligibly small. It is expected that aggregated nanoparticles result in much higher oscillations.Ministry of Science and Innovation, Spain grant numbers PID2019-106947RA-C2FEDER EQC2018-004508-

Estrategias para la competitividad de la cadena láctea en el Departamento del Caquetá

En el Departamento de Caquetá (Colombia), se analizó información levantada por varios autores sobre la producción departamental de leche, con el fin de caracterizar la cadena láctea en el Departamento y proponer estrategias tendientes al fortalecimiento de su competitividad. Se encontró que los pequeños y medianos productores de leche en el Caquetá afrontan problemas de baja productividad e infraestructura, y la informalidad en la comercialización de los productos lácteos, lo que conlleva altos costos de producción y dificultades en la transformación y comercialización de la leche. Adicionalmente, este importante renglón económico departamental enfrenta la entrada en vigencia de nuevas normas nacionales para el pago de la leche y la suscripción de diferentes tratados de libre comercio, hechos que demandan el fortalecimiento inmediato de la competitividad de la cadena láctea departamental

Photo-assisted ozonation of cefuroxime with solar radiation in a CPC pilot plant. kinetic parameters determination

The combination of ozone and solar radiation can be considered an effective technology as advanced oxidation process, AOP, for addressing the removal of harmful contaminants of emerging concern in water. Cefuroxime is an example of an antibiotic whose presence may result in a problem if not conveniently removed from the water. Cefuroxime oxidation has been performed employing photolytic ozonation in an autonomous pilot plant, consisting of a solar collector photo-reactor with ozone feeding, solar panel cells, and batteries for energy demands. Firstly, the kinetics of cefuroxime ozonation has been deeply studied in an agitation cell reactor. The stoichiometric ozonation ratio was estimated as zO3 = 1.00 ± 0.06 (O3 mol per cefuroxime mol) and the second-order rate constant in the range 1.50 × 106 – 4.69 × 106 M−1 s−1 for the non-dissociated and dissociated, respectively, cefuroxime molecule. The oxidation intermediates identified included hydroxylation of the initial molecule, attack to the secondary amide group and oxidation of the bi-substituted sulfide position. Secondly, the simultaneous application of ozone and solar radiation in the CPC pilot plant enhanced the degradation of cefuroxime. The kinetics in the CPC reactor was simulated and the importance of the hydroxyl radical over ozonation and photolysis was confirmed, 55% of HO• contribution. Also, over 55% of mineralization was observed during photolytic ozonation in wastewater matrix whereas single ozonation only was able to partially oxidize the initial organic content to short organic acids (formic, acetic, and oxalic) that were accumulated in the wate

Arteritis de Takayasu

En Pediatría la Arteritis de Takayasu es una enfermedad rara. Es una de las mayores causas de hipertensión renovascular y la tercera vasculitis más común, después de la Púrpura de Henoch Schönlein y de la Enfermedad de Kawasaki. Las manifestaciones clínicas son variables, desde fiebre y fatiga a presentaciones severas, como accidente cerebrovascular. Se publica el caso de una paciente de 13 años, referida a nuestro hospital con diagnóstico de accidente cerebrovascular y aneurisma disecante de aorta tóracoabdominal, se revisan los criterios diagnósticos y su evolución. DOI:https://doi.org/10.25176/RFMH.v17.n1.75

Inter-Rater Variability in the Evaluation of Lung Ultrasound in Videos Acquired from COVID-19 Patients

12 páginas, 7 figuras, 1 tablaLung ultrasound (LUS) allows for the detection of a series of manifestations of COVID-19, such as B-lines and consolidations. The objective of this work was to study the inter-rater reliability (IRR) when detecting signs associated with COVID-19 in the LUS, as well as the performance of the test in a longitudinal or transverse orientation. Thirty-three physicians with advanced experience in LUS independently evaluated ultrasound videos previously acquired using the ULTRACOV system on 20 patients with confirmed COVID-19. For each patient, 24 videos of 3 s were acquired (using 12 positions with the probe in longitudinal and transverse orientations). The physicians had no information about the patients or other previous evaluations. The score assigned to each acquisition followed the convention applied in previous studies. A substantial IRR was found in the cases of normal LUS (κ = 0.74), with only a fair IRR for the presence of individual B-lines (κ = 0.36) and for confluent B-lines occupying 50% (κ = 0.50). No statistically significant differences between the longitudinal and transverse scans were found. The IRR for LUS of COVID-19 patients may benefit from more standardized clinical protocols.This research was partially funded by CDTI (Spanish acronym: Centre for Industrial Tech- nological Development), funding number COI-20201153. Partially supported by the Google Cloud Research Credits program with the funding number GCP19980904, by the project RTI2018-099118- A-I00 founded by MCIU/AEI/FEDER UE and by the European Commission–NextGenerationEU, through CSIC’s Global Health Platform (PTI Salud Global)