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Finlandia Reforma su Sistema Educativo Estudio por temas en lugar de por asignaturas


Finlandia encara una nueva reforma de su sistema educativo, en la búsqueda de mejora continua a través de la innovación.

El nuevo paradigma educativo implica un proceso de cambio que consiste en la eliminación gradual de la enseñanza por asignaturas, hasta el año 2020, para dar lugar a la enseñanza por temas. Llevado a la práctica este nuevo aprendizaje, permitiría a los alumnos desarrollar un tema en particular que implique el manejo de conocimientos de química, física, mátemáticas u otra asignatura en particular, según sea el caso.

Distilling Pure Anhydrous Ammonia Applied Science

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I have a few upcoming projects that require anhydrous ammonia. In this video, I show how to distill it from "ammonia water" similar to common glass cleaner.

Fuente: Applied Science

Calculadora en Línea Wolfram Alpha

Calculadora en línea de Wolfram Alpha
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Light Absorption Properties and Radiative Effects of Primary Organic Aerosol Emissions


Light Absorption Properties and Radiative Effects of Primary Organic Aerosol Emissions
Zifeng Lu, David G. Streets, Ekbordin Winijkul, Fang Yan, Yanju Chen, Tami C. Bond, Yan Feng, Manvendra K. Dubey, Shang Liu, Joseph P. Pinto, and Gregory R. Carmichael
Environmental Science & Technology Article ASAP
DOI: 10.1021/acs.est.5b00211

Organic aerosols (OAs) in the atmosphere affect Earth’s energy budget by not only scattering but also absorbing solar radiation due to the presence of the so-called “brown carbon” (BrC) component.

However, the absorptivities of OAs are not represented or are poorly represented in current climate and chemical transport models. In this study, we provide a method to constrain the BrC absorptivity at the emission inventory level using recent laboratory and field observations.

We review available measurements of the light-absorbing primary OA (POA), and quantify the wavelength-dependent imaginary refractive indices (kOA, the fundamental optical parameter determining the particle’s absorptivity) and their uncertainties for the bulk POA emitted from biomass/biofuel, lignite, propane, and oil combustion sources. In particular, we parametrize the kOA of biomass/biofuel combustion sources as a function of the black carbon (BC)-to-OA ratio, indicating that the absorptive properties of POA depend strongly on burning conditions.

The derived fuel-type-based kOA profiles are incorporated into a global carbonaceous aerosol emission inventory, and the integrated kOA values of sectoral and total POA emissions are presented. Results of a simple radiative transfer model show that the POA absorptivity warms the atmosphere significantly and leads to ∼27% reduction in the amount of the net global average POA cooling compared to results from the nonabsorbing assumption.

Ver más: ACS