Contribución del aplanado de morteros de cal para restauración sobre muretes de mampostería

Los morteros con base cal, han sido materiales descritos en los tratados antiguos de arquitectura, permitidos en muchos documentos que rigen los trabajos de restauración de bienes inmuebles patrimoniales y actualmente son los materiales más empleados en la restauración y conservación del patrimonio de mampostería natural en muchos sitios del mundo. La cal puede ser normalizada o bien puede ser apagada en sitio como describe Vitrubio en sus Libros de Arquitectura; los áridos pueden ser ígneos, metamórficos o sedimentarios; para modificar las propiedades físicas y mecánicas básicas de los morteros de cal suelen agregarse aditivos orgánicos e inorgánicos. La restauración y conservación de los edificios de mampostería coloniales es un reto en México. Tenemos 9 ciudades coloniales cuyos centros históricos están en el listado de Patrimonio de la Humanidad de la Unesco. Todas edificadas con mamposterías de rocas naturales y aplanadas con morteros de cal y aditivos orgánicos. Inicialmente se recubrían las rocas que carecían de labrado, cánones dictados por la arquitectura en boga. Con la modernización y masificación del transporte, los residuos vertidos a la atmósfera han deteriorado la calidad del aire ambiental resultando en pátinas, costras negras, daño antropogénico en superficies expuestas, devitrificación de la matriz de las rocas. Del uso sugerido de emplear morteros como protección en los monumentos arquitectónicos coloniales, método relativamente simple y económico, se ha revisado también su efecto sobre la resistencia mecánica. Este trabajo hace una comparación entre pilas de mampostería de arcilla recocida adheridas con mortero de cal adicionado con fibras desecadas y pulverizadas de nopal cactus opuntia y pilas con las mismas características, pero recubiertas en ambas caras con el mortero mencionado.Tópico 4.- Morteros de cal, materiales cálcicos y cementíceos. Evaluación de propiedades y composición. Mampostería de ladrillos. Caracterización. Evaluación de patologías y Refuerzo

Colombian consensus on the diagnosis, treatment, and prevention of candida Spp. disease in children and adults

La Candidiasis Invasora (CI) y la candidemia, como su manifestación más frecuente, se ha convertido en la principal causa de micosis oportunista a nivel hospitalario. Este manuscrito realizado por miembros de la Asociación Colombiana de Infectología (ACIN), tuvo como objetivo proporcionar un conjunto de recomendaciones para manejo, seguimiento y prevención de la CI/candidemia y de la infección candidiásica de mucosas, en población adulta, pediátrica y neonatal, en un entorno hospitalario, incluyendo las unidades hemato-oncológicas y unidades de cuidado crítico. Todos los datos obtenidos mediante una búsqueda exhaustiva, fueron revisados y analizados de manera amplia por todos los miembros del grupo, y las recomendaciones emitidas se elaboraron luego de la evaluación de la literatura científica disponible, y el consenso de todos los especialistas involucrados, reconociendo el problema de la emergencia de las infecciones por Candida Spp. y brindando una correcta orientación a los profesionales de la salud sobre el manejo de pacientes con enfermedad candidiásica, de una forma racional y práctica, enfatizando en la evaluación del paciente, estrategias de diagnóstico, profilaxis, tratamiento empírico, tratamiento dirigido y terapia preventiva.Invasive Candidiasis (IC) and candidemia (as its most frequent manifestation) have become the main cause of opportunistic mycosis at hospital settings. This study, made by members of the Colombian Association of Infectious Diseases (ACIN), was aimed at providing a set of recommendations for the management, follow-up and prevention of IC / candidemia and mucous membrane candida infection in adult, pediatric and neonatal patients in a hospital setting, including the hemato-oncological and critical care units. All the data obtained through an exhaustive search were reviewed and analyzed in a comprehensive manner by all the members of the group, and the recommendations issued are being made after a careful review of the scientific literature available and the consensus of all specialists involved; the emergence of Candida Spp. problem is highlighted and a correct orientation to health professionals regarding the management of patients with candidiasis is provided in a rational and practical way, emphasizing patient evaluation, diagnostic strategies, prophylaxis, empirical treatment, directed treatment and preventative therap

Systems Engineering Methodology for Verification of PV Module Parameter Solutions

Numerous sources provide methods to extract photovoltaic (PV) parameters from PV module datasheet values. The inputs are the number of series cells $\text{N}_{\mathrm {s}}$ , open circuit voltage $\text{V}_{\mathrm {oc}}$ , maximum power voltage $\text{V}_{\mathrm {mp}}$ , maximum power current $\text{I}_{\mathrm {mp}}$ , and short circuit current $\text{I}_{\mathrm {sc}}$ . The 5 Parameter Model solutions outputs are diode ideality factor $\eta$ , series resistance $\text{R}_{\mathrm {s}}$ , parallel resistance $\text{R}_{\mathrm {p}}$ , photon light current $\text{I}_{\mathrm {L}}$ , and diode reverse saturation current $\text{I}_{\mathrm {o}}$ . The parameter solution requires solving three simultaneous transcendental equations for $\eta$ , $\text{R}_{\mathrm {s}}$ , and $\text{R}_{\mathrm {p}}$ and additional calculations for $\text{I}_{\mathrm {L}}$ and $\text{I}_{\mathrm {o}}$ . One of the primary tenants of Systems Engineering, verification, was applied to parameter solution results to check for physical and model fitness. This manuscript provides novel methods to verify parameter results and applies them to available solutions

Laser Injection of Soft Faults for the Validation of Dependability Design

Abstract: The expanding application of computing systems and the continuing advances in semiconductor technology are forcing the on-chip inclusion of design for dependability features (concurrent fault tolerance). These features detect, log and provide recovery from errors induced by faults concurrently with the operation of the system. A very difficult task is the hardware validation of concurrent fault tolerant design features in a nondestructive, unobtrusive manner. A semi-automated facility has been developed at the University of South Florida for this purpose using Laser Fault Injection (LFI) to simulate soft errors during system operation. The facility provides means to extract target coordinates from the CAD database, synchronize the laser pulse with the operation of and capture health warnings issued by the system under test. The key fault tolerant features (automatic instruction retry on single soft errors) of a state of the art fault tolerant computer for space applications were validated at this facility

Salinity Gradient Power (SGP): A Developmental Roadmap Covering Existing Generation Technologies and Recent Investigative Results into the Feasibility of Bipolar Membrane-Based Salinity Gradient Power Generation

Besides wind and solar-based renewable energy technologies, marine sources are being actively discussed. Sources of marine renewable energy traditionally have included ocean currents, ocean waves, tides, thermal gradients, and salinity gradients. Salinity gradient power (SGP) is an attractive marine renewable resource because it possesses not only the largest energy potential but likely the largest total available resource as well. SGP is instantly available when diluted and concentrated ionic solutions are mixed; is renewable, sustainable, and produces no CO2 emissions or other significant effluents that may interfere with global climate. The ultimate challenge is in the economics of the recovery method used and the matching of the resulting energy density delivered to a suitable end application. The transformative technical challenges required in advancing the knowledge and understanding of SGP, both within and across related scientific fields, lies in advances in membrane development, supply source utilization, energy generation, and storage/delivery of the generated power. This article begins with an introductory overview of SGP, provides background into the major SGP membrane-based processes under development, and then discusses recent investigative results into the use of bipolar membranes in SGP generation applications

Computational Fluid Dynamic Analysis of Flow Velocity Waveform Notching in Umbilical Arteries

Umbilical artery Doppler velocimetry waveform notching has long been associated with umbilical cord abnormalities, such as distortion, torsion, and/or compression (i.e., constriction). The physical mechanism by which the notching occurs has not been elucidated. Flow velocity waveforms (FVWs) from two-dimensional pulsatile flows in a constricted channel approximating a compressed umbilical cord are analyzed, leading to a clear relationship between the notching and the constriction. Two flows with an asymmetric, semi-elliptical constriction are computed using a stabilized finite-element method. In one case, the constriction blocks 75% of the flow passage, and in the other the constriction blocks 85%. Channel width and prescribed flow rates at the channel inflow are consistent with typical cord diameters and flow rates reported in the literature. Computational results indicate that waveform notching is caused by flow separation induced by the constriction, giving rise to a vortex (core) wave and associated eddies. Notching in FVWs based on centerline velocity (centerline FVW) is directly related to the passage of an eddy over the point of measurement on the centerline. Notching in FVWs based on maximum cross-sectional velocity (envelope FVW) is directly related to acceleration and deceleration of the fluid along the vortex wave. Results show that notching in envelope FVW is not present in flows with less than a 75% constriction. Furthermore, notching disappears as the vortex wave is attenuated at distances downstream of the constriction. In the flows with 75 and 85% constriction, notching of the envelope FVW disappears at ∼3.8 and ∼4.3 cm (respectively) downstream of the constriction. These results are of significant medical importance, given that envelope FVW is typically measured by commercial Doppler systems

Computational Fluid Dynamic Analysis of Flow Velocity Waveform Notching in Umbilical Arteries

Umbilical artery Doppler velocimetry waveform notching has long been associated with umbilical cord abnormalities, such as distortion, torsion, and/or compression (i.e., constriction). The physical mechanism by which the notching occurs has not been elucidated. Flow velocity waveforms (FVWs) from two-dimensional pulsatile flows in a constricted channel approximating a compressed umbilical cord are analyzed, leading to a clear relationship between the notching and the constriction. Two flows with an asymmetric, semi-elliptical constriction are computed using a stabilized finite-element method. In one case, the constriction blocks 75% of the flow passage, and in the other the constriction blocks 85%. Channel width and prescribed flow rates at the channel inflow are consistent with typical cord diameters and flow rates reported in the literature. Computational results indicate that waveform notching is caused by flow separation induced by the constriction, giving rise to a vortex (core) wave and associated eddies. Notching in FVWs based on centerline velocity (centerline FVW) is directly related to the passage of an eddy over the point of measurement on the centerline. Notching in FVWs based on maximum cross-sectional velocity (envelope FVW) is directly related to acceleration and deceleration of the fluid along the vortex wave. Results show that notching in envelope FVW is not present in flows with less than a 75% constriction. Furthermore, notching disappears as the vortex wave is attenuated at distances downstream of the constriction. In the flows with 75 and 85% constriction, notching of the envelope FVW disappears at ∼3.8 and ∼4.3 cm (respectively) downstream of the constriction. These results are of significant medical importance, given that envelope FVW is typically measured by commercial Doppler systems