High-order div- and quasi curl-conforming basis functions for calderon multiplicative preconditioning of the EFIE

A new high-order Calderon multiplicative preconditioner (HO-CMP) for the electric field integral equation (EFIE) is presented. In contrast to previous CMPs, the proposed preconditioner allows for high-order surface representations and current expansions by using a novel set of high-order quasi curl-conforming basis functions. Like its predecessors, the HO-CMP can be seamlessly integrated into existing EFIE codes. Numerical results demonstrate that the linear systems of equations obtained using the proposed HO-CMP converge rapidly, regardless of the mesh density and of the order of the current expansion

High-Order Calderon Preconditioning of Integral Equations for the Analysis of Scattering from PEC and Homogeneous Penetrable Objects.

Boundary integral equations often are used to analyze transient and time-harmonic scattering from perfect electrically conducting (PEC) as well as homogeneous penetrable objects. When discretized, these equations give rise to linear systems of equations that can be solved for the induced currents on the surface of the scatterer. Unfortunately, standard formulations have the property that whenever the mesh discretization increases, the frequency approaches zero, or it is close to a resonance, the condition number of these systems grows rapidly. From a numerical perspective these properties are problematic as they slow down or even preclude the use of iterative solvers. Previous work in this area has provided with new (regularized) equations that overcome these problems, but their applicability has been limited exclusively to zeroth-order representations of the current expansions. The objective of this research is to extend the applicability of existing regularized equations applicable to PEC structures, and to provide with new equations suitable for homogeneous penetrable objects. First, a new set of high-order div- and quasi curl-conforming basis functions is presented. With these functions, several existing equations for PEC structures are implemented using high-order representations for the surface of the scatterer and the current expansions. Time-domain and frequency-domain regularized equations are explored. Numerical results demonstrate that high-order implementation of these equations preserves the desired properties of their predecessors, yet they exhibit the advantage of using high-order representations. Second, a new regularized single source equation for analyzing scattering from homogeneous penetrable objects in frequency-domain is presented. The proposed equation is immune to low-frequency and densemesh breakdown, and free from spurious resonances. This single source equation is discretized using a combination of basis functions (including those presented here), thereby fully respecting the space mapping properties of the operators involved, and guaranteeing accuracy and stability. Numerical results show that the proposed equation and discretization technique give rise to rapidly convergent solutions. They also validate the equation’s resonant free character. With this same discretization scheme, (non-regularized) time-domain single source equations are also explored.Ph.D.Electrical EngineeringUniversity of Michigan, Horace H. Rackham School of Graduate Studieshttp://deepblue.lib.umich.edu/bitstream/2027.42/91563/1/fvaldes_1.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/91563/2/fvaldes_2.pd

Draft Genome Sequence of Bacillus safensis RP10, Isolated from Soil in the Atacama Desert, Chile.

Genome analysis of Bacillus safensis RP10, a strain from the soil of Atacama Desert in northern Chile, reflects a bacterium adapted to live in soil containing high levels of heavy metals, high salt conditions, and low carbon and energy sources

Consideraciones juridicas entorno al consentimiento en la Ley 19.451.

47 h. ; 28 cm.Este trabajo aborda algunos elementos de la ley 19.451 sobre trasplantes de órganos. El primer capítulo desarrolla algunas generalidades en torno a la ley 19.451 y a los trasplantes de órganos. El segundo capítulo aborda la problemática de la muerte cerebral tanto en sus aspectos generales, como en el derecho español y chileno. El tercer capítulo desarrolla la problemática de la validez del consentimiento de donar según la ley 19.451. Finalmente, el cuarto capítulo desarrolla algunos elementos básicos de la llamada “socialización del cadáver”

Metallurgical Characterization of a Weld Bead Coating Applied by the PTA Process on the D2 Tool Steel

Abstract In this investigation, a nickel-base powder mixed with tungsten carbide particles was applied by Plasma Transferred Arc welding (PTA) on the surface of the D2 cold work tool steel to improve surface quality and to extend its lifetime during applications. The Design of Experiment (DoE) method was applied to obtain the appropriate combination of hardfacing parameters and to run the minimum number of tests. Current, travel speed and preheat were considered as variable parameters. These parameters are important to reach a final layer with an appropriate bead geometry accompanied with good metallurgical properties. All samples were prepared for metallurgical investigations and the effect of process parameters on the weld bead geometry was considered. For each experiment run, weld bead geometry parameters were measured including dilution, penetration and reinforcement. Microstructures and the distribution of tungsten carbide particles after welding were analyzed by Optical Microscopy (OM) and Scanning Electron Microscopy (SEM) equipped with an EDS microprobe. In addition, hardness tests were performed to evaluate the mechanical properties of the weld bead layers. Finally, among all the experiments, the best sample with appropriate bead geometry and microstructure was selected

The effect of exercise on cardiovascular risk markers in Mexican school-aged children: comparison between two structured group routines

Objective. To assess the effects of two groups of exercise routines on cardiovascular disease risk markers. Material and Methods. An intervention study was conducted with 319 Mexican school-aged children in which routines were implemented Monday through Friday for 12 weeks. Routine A was the reference group, with 20 min of less intense activity and routine B was the new group with 40 min of aerobic exercises. Body mass index (BMI), waist circumference, fat mass percentage (FM%), systolic and diastolic blood pressure, lipids, lipoproteins, glucose and insulin were measured before and after the intervention. Results. Routine A had an effect on diastolic pressure, while routine B had an effect on BMI, FM%, blood pressure and triglycerides. Routine B had a greater effect on blood pressure than routine A. The prevalence of obesity, high blood pressure and hypertriglyceridemia decreased in both groups. Conclusion. Aerobic exercise is an effective health promotion strategy to reduce some cardiovascular disease risk markers

Optomechanical accelerometers for geodesy

We present a novel optomechanical inertial sensor for low frequency applications and corresponding acceleration measurements. This sensor has a resonant frequency of 4.7Hz, a mechanical quality factor of 476k, a test mass of 2.6 gram, and a projected noise floor of approximately 5E-11 m s-2. per root-Hz at 1Hz. Such performance, together with its small size, low weight, reduced power consumption, and low susceptibility to environmental variables such as magnetic field or drag conditions makes it an attractive technology for future geodesy missions. In this paper, we present an experimental demonstration of low-frequency ground seismic noise detection by direct comparison with a commercial seismometer, anda data analysis algorithms for the identification, characterization, and correction of several noise sources

Guía preparación y respuesta ante emergencias – Modalidad Teletrabajo

Brindar una guía necesaria para la preparación y respuesta ante emergencias para los colaboradores que desarrollan sus labores en modalidad de teletrabajo, en el marco del cumplimiento de la ISO 45001:2018, así como salvaguardar la vida de sus familias y los bienes de las empresas para las cuales trabajanA raíz de la pandemia ocasionada por el SARS-CoV-2 muchas empresas colombianas se reinventaron, teniendo en cuenta el ordenamiento de cuarentena obligatoria por un tiempo determinado, ocasionando que se optara por usar la modalidad de Teletrabajo como una alternativa al trabajo remoto. La normatividad establecida por el gobierno nacional tiene vacíos en la identificación de posibles amenazas (Sismo, inundación, incendio y tsunami) en los domicilios de los colaboradores. A su vez los colaboradores no cuentan con una guía que les oriente sobre los elementos necesarios para la atención a una posible emergencia (botiquín, extintor y kit de emergencia). Lo que busca el desarrollo de esta monografía es generar una guía para la preparación y respuesta ante emergencias para aquellos colaboradores que desarrollan sus labores en modalidad de teletrabajo, en el marco del cumplimiento de la ISO 45001:2018, así como salvaguardar la vida de sus familias y los bienes de las empresas para las cuales trabajan. Las personas en general usualmente no cuentan con un plan de preparación frente a una situación de emergencia, medida importante que puede marcar la diferencia entre la vida y la muerte. Seria de suma importancia que el gobierno nacional pudiese establecer un lineamiento preciso para la construcción de la guía con el fin de ser inclusivos con los teletrabajadores en materia de gestión de riesgos laborales y amenazas presentes en el lugar de trabaj