154 research outputs found

    Procesos de selección de personal en los gimnasios de la Ciudad de Mendoza, en el 2012

    Get PDF
    El recurso humano debería ser considerado como un activo indispensable en toda organización ya que, sin él, ésta puede ver perjudicados o –peor aún– no cumplir sus objetivos. Cada entidad define la importancia del proceso de selección dependiendo del puesto y perfil deseado. Los gimnasios de Mendoza reclutan profesores y licenciados en educación física egresados de distintos entes formadores. Nos preocupa conocer los procesos más usados y cuáles son los elementos que se tienen en cuenta a la hora de seleccionar a los docentes de sus gimnasios. Detectar cuáles son los procesos de selección de personal docente que se realizan en los gimnasios de la Ciudad de Mendoza y realizar el análisis comparativo con lo que la teoría delimita como ideal

    Toward Smart And Sustainable Cement Manufacturing Process: Analysis And Optimization Of Cement Clinker Quality Using Thermodynamic And Data-Informed Approaches

    Get PDF
    Cement manufacturing is widely recognized for its harmful impacts on the natural environment. In recent years, efforts have been made to improve the sustainability of cement manufacturing through the use of renewable energy, the capture of CO2 emissions, and partial replacement of cement with supplementary cementitious materials. To further enhance sustainability, optimizing the cement manufacturing process is essential. This can be achieved through the prediction and optimization of clinker phases in relation to chemical compositions of raw materials and manufacturing conditions. Cement clinkers are produced by heating raw materials in kilns, where both raw material compositions and processing conditions dictate the final chemical makeup of the clinkers. This study uses thermodynamic simulations to analyze phase assemblages of alite- and belite-enriched clinkers based on chemical compositions of raw materials and to create a database. The thermodynamic simulations can accurately reproduce clinker phases in comparison with experimental results. Subsequently, the simulated database is employed to train a data-informed model, and the predictions are used to determine the optimal composition domains that produce high quality clinker (C3S\u3e50 %) at different calcination temperatures. Additionally, optimal lime saturation factor and alumina modulus are investigated to achieve target clinker phases. Overall, this study demonstrates the potential of using a data-informed approach to achieve smart and sustainable cement manufacturing process

    Dissipational versus Dissipationless Galaxy Formation and the Dark Matter Content of Galaxies

    Full text link
    We examine two extreme models for the build-up of the stellar component of luminous elliptical galaxies. In one case, we assume the build-up of stars is dissipational, with centrally accreted gas radiating away its orbital and thermal energy; the dark matter halo will undergo adiabatic contraction and the central dark matter density profile will steepen. For the second model, we assume the central galaxy is assembled by a series of dissipationless mergers of stellar clumps that have formed far from the nascent galaxy. In order to be accreted, these clumps lose their orbital energy to the dark matter halo via dynamical friction, thereby heating the central dark matter and smoothing the dark matter density cusp. The central dark matter density profiles differ drastically between these models. For the isolated elliptical galaxy, NGC 4494, the central dark matter densities follow the power-laws r^(-0.2) and r^(-1.7) for the dissipational and dissipationless models, respectively. By matching the dissipational and dissipationless models to observations of the stellar component of elliptical galaxies, we examine the relative contributions of dissipational and dissipationless mergers to the formation of elliptical galaxies and look for observational tests that will distinguish between these models. Comparisons to strong lensing brightest cluster galaxies yield median M*/L_B ratios of 2.1+/-0.8 and 5.2+/-1.7 at z=0.39 for the dissipational and dissipationless models, respectively. For NGC 4494, the best-fit dissipational and dissipationless models have M*/L_B=2.97 and 3.96. Comparisons to expected stellar mass-to-light ratios from passive evolution and population syntheses appear to rule out a purely dissipational formation mechanism for the central stellar regions of giant elliptical galaxies.Comment: 15 pages, 9 figures, accepted to Ap

    High-Redshift Star-Forming Galaxies: Angular Momentum and Baryon Fraction, Turbulent Pressure Effects and the Origin of Turbulence

    Full text link
    The structure of a sample of high-redshift (z=2), rotating galaxies with high star formation rates and turbulent gas velocities of sigma=40-80 km/s is investigated. Fitting the observed disk rotational velocities and radii with a Mo, Mao, White (1998) (MMW) model requires unusually large disk spin parameters lambda_d>0.1 and disk-to-dark halo mass fraction m_d=0.2, close to the cosmic baryon fraction. The galaxies segregate into dispersion-dominated systems with 1<vmax/sigma<3, maximum rotational velocities vmax<200 km/s and disk half-light radii rd=1-3 kpc and rotation-dominated systems with vmax>200 km/s, vmax/sigma>3 and rd=4-8 kpc. For the dispersion-dominated sample, radial pressure gradients partly compensate the gravitational force, reducing the rotational velocities. Including this pressure effect in the MMW model, dispersion-dominated galaxies can be fitted well with spin parameters lf lambda_d=0.03-0.05 for high disk mass fractions of m_d=0.2 and with lambda_d=0.01-0.03 for m_d=0.05. These values are in good agreement with cosmological expectations. For the rotation-dominated sample however pressure effects are small and better agreement with theoretically expected disk spin parameters can only be achieved if the dark halo mass contribution in the visible disk regime (2-3*rd) is smaller than predicted by the MMW model. We argue that these galaxies can still be embedded in standard cold dark matter halos if the halos did not contract adiabatically in response to disk formation. It is shown that the observed high turbulent gas motions of the galaxies are consistent with a Toomre instability parameter Q=1 which is equal to the critical value, expected for gravitational disk instability to be the major driver of turbulence. The dominant energy source of turbulence is then the potential energy of the gas in the disk.Comment: 23 pages, 4 figures, ApJ, in pres

    ENGENHARIA DE TRÁFEGO: ESTATÍSTICA DO FLUXO DE CARROS NO BAIRRO FAROLÂNDIA

    Get PDF
    O presente trabalho apresenta modelos estatísticos de dados coletados no bairro Farolândia, em Aracaju-SE, Brasil. A engenharia de tráfego, por envolver muitos dados, é complexa, o que exige um tratamento estatístico buscando valores seguros através dos intervalos de confiança. O início da pesquisa foi marcado por um levantamento bibliográfico para buscar alternativas de abordar o tema de engenharia de tráfego. O bairro Farolândia por possuir grande concentração de moradores, dentre eles estudantes universitários, possuir uma das maiores universidades do Norte-Nordeste, a Universidade Tiradentes, e envolver um grande número de veículos diariamente, foi o local escolhido para a realização da pesquisa. Através dos dados coletados em pesquisa de campo, foi possível realizar a comparação do número de veículos na região antes e depois da implantação do semáforo em frente a Universidade. Os resultados encontrados foram que após a implantação do semáforo, o fluxo de veículos aumentou na região. Mesmo com o aumento do número de veículos, o transtorno anteriormente causado pelos constantes engarrafamentos diminuiu. Para eliminar o engarrafamento que ainda restou em uma das vias, propôs-se o asfaltamento de outra via, melhorando o tráfego no local

    Vicious and Virtuous Cycles and the Role of External Non-government Actors in Community Forestry in Oaxaca and Michoacán, Mexico

    Get PDF
    Community forestry offers potential for socioeconomic benefits while maintaining ecosystem services. In Mexico, government and donor efforts to develop this sector focus on issues within forest communities. Often overlooked are effects of external non-government actors (NGOs and foresters) as links or barriers between communities and funding, capacity building, and technical support. To analyze the role of these actors, I analyze household survey and interview data from 11 communities with varying levels of vertical integration of forestry production in states with divergent records of community forestry, Oaxaca and Michoacán. Results suggest that strong community governance is necessary but not sufficient for vertical integration, and strong interactions with non-government actors are critical. These actors, operating within the existing framework of government regulations, have a range of incentives for engaging communities. Availability of these actors motivated by concern for community capacity instead of timber income may be a determinant of community forestry development

    Substrate Coating Produced via Additive Manufacturing with Conducting Polymers: Assessment in The Development of Electrodes

    Get PDF
    The production of conductive and organic devices from a 3D printer represents a promising strategy for several areas. In particular, the synthesis of polypyrrole-coated acrylonitrile butadiene styrene (ABS) composites can be considered an important step to produce conductive supports for 3D printing. Herein, it is reported the production of ABS samples through the additive manufacturing process (3D printing) accordingly to the Fused Deposition Modeling (FDM) method. The hydrophilic behavior was controlled by the surface treatment using air plasma for the following step of coating with polypyrrole (PPy) via an in situ polymerization, using two different oxidants: ferric chloride (FeCl3.6H2O) and ammonium persulfate (APS). The chemical, optical, surface, and electrical properties of these materials were characterized through Fourier Transform infrared spectroscopy (FTIR), contact angle measurements, cyclic voltammetry, Scanning Electron Microscopy (SEM), 4-probe electrical measurement, and mechanical tensile testing. The ABS/PPy (FeCl3) composite exhibited a low electrical contact resistance and better performance for applications that require electrodes with a good conductance level
    corecore