1,319 research outputs found
Alteration and alterability of the anorthosite from Angola
Siliceous rocks are widely used as dimension stone but the last decades have registered an increase rate of their alteration when exposed to polluted environments. Anorthosites were treated by acidified solutions of HCl, HN03 and H2S04 simulating acid rain and the response was recorded through different experiments such as on the surface of the polished rock and on the surface of uncovered thin sections. The main components, plagioclase and olivine, both responded in similar ways to each acid solution, although following different trends; while plagioclase develops a thin layer which acts as protection to the mineral, olivine at first undergoes alteration due to leaching of magnesium and iron and in a following stage, is mechanically removed from the rock. The
action of warm water on the rock was tested through the use of the Soxhlet extractor which caused changes on the rock colour
and leaching of several cations from its components
Partial molar volumes of glycine and L-Alanine in aqueous MgSO4 solutions between 278.15 and 308.15 K
In this work, partial molar volumes of glycine and L-alanine in aqueous solutions of magnesium sulphate at (0.0, 0.1, 0.3, 0.7 and 1.0) molal were obtained between 278.15 K and 308.15 K.
Additionally, partial molar volumes of transfer at infinite dilution and hydration numbers were calculated. In general, transfer volumes are higher for glycine then L-alanine. From the transfer volumes, it can be concluded that the predominant interactions are pairwise between ions and zwitterionic centers of the amino acids. On the other hand, hydration numbers are higher for L-alanine than glycine. Dehydration of the studied amino acids is observed, rising either temperature or salt molality.This work is supported by project Project PEst-C/EQB/LA0020/2013, financed by FEDER through COMPETE - Programa Operacional Factores de Competitividade and by FCT - Fundação para a Ciência e a Tecnologia. This work was also co-financed by QREN, ON2 and FEDER (Project NORTE-07-0162-FEDER-000050)
Fishers Participation in Coastal Fisheries Co-management: The Case of the Community of Trindade, in Southeastern Coast of Brazil
Admissão de Doentes com Cancro do Pulmão nas Unidades de Cuidados Intensivos
info:eu-repo/semantics/publishedVersio
Mathematica in the classroom: new tools for exploring precalculus and differential calculus
Prémio de Melhor Artigo de Jovem Investigador atribuÃdo pela empresa Timberlake, apresentado na 1ª Conferência Nacional sobre Computação Simbólica no Ensino e na Investigação -
CSEI2012, que decorreu no IST nos dias 2 e 3 de Abril.The main goal of this paper is to present some interactive tools, F-Tools, designed by us and implemented with the computer algebra system Mathematica, which we hope will improve the teaching-and-learning process by providing teachers and students alike with new ways to explore some of the main mathematical subjects, at the secondary and university levels, speci cally in the
areas of precalculus and di erential calculus. We believe that these new tools are an important contribution to Mathematical Education, providing new ways for teaching and learning. We intend to make available several F-Tools, such as F-Linear, F-Quadratic, F-Exponential, F-Logarithm, and F-Trigonometric, at the Wolfram Demonstrations Project site
F-Quadratic
The article (see http://hdl.handle.net/10400.1/1105) was first presented in the 1st National Conference on Symbolic Computation in Education and Research, IST Portugal 2012, where distinguished with the Timberlake Award for Best Article by a Young Researcher. On how to work with the CDF format please see http://www.wolfram.com/cdf-player/.F-Quadratic is a F-Tool (see http://hdl.handle.net/10400.1/1105), that is, a visual, dynamic, and interactive teaching tool that allow to explore in an innovate fashion some of the main concepts within precalculus and differential calculus at the secondary and university levels (available in the CDF format)
F-Linear
The article (see http://hdl.handle.net/10400.1/1105) was first presented in the 1st National Conference on Symbolic Computation in Education and Research, IST Portugal 2012, where distinguished with the Timberlake Award for Best Article by a Young Researcher. On how to work with the CDF format please see http://www.wolfram.com/cdf-player/.F-Linear is a F-Tool (see http://hdl.handle.net/10400.1/1105), that is, a visual, dynamic, and interactive teaching tool that allow to explore in an innovate fashion some of the main concepts within precalculus and differential calculus at the secondary and university levels (available in the CDF format)
- …