Extremal polynomials in stratified groups

We introduce a family of extremal polynomials associated with the prolongation of a stratified nilpotent Lie algebra. These polynomials tre related to a new algebraic characterization of abnormal sub-Riemannian extremals in stratified nilpotent Lie groups. They satisfy a set of remarkable structure relations that are used to integrate the adjoint equations, in both normal and abnormal case

Texas Business Review, January 1977

How Oil Supports Prosperity in Texas; El Paso Economic Profile; Construction Activity and the Tax Reform Act of 1976Bureau of Business Researc

Texas Business Review, October 1976

To Push or Not To Push; Tracking Intracity Changes; Killeen-Temple: Magnet AreaBureau of Business Researc

Breeze analysis by mast and sodar measurements

During the year 1993, field measurements were carried out in a meteorological station located in the neighbourhood of Rome, 10 km from the coast (Tyrrhenian Sea). The monitoring station is composed of a 30 m mast and a three-axial Doppler sodar. A statistical analysis of data has been made in order to obtain the main parameters utilised by the dispersion model. Hourly, seasonal and conditional averages showed the strong influence of sea and land breeze circulation on the local characteristics of the atmospheric boundary layer. Such an aspect has to be considered in the numerical predictions of pollutant dispersion

¿Podemos integrar matemática, química, computación a partir de una problemática actual?

Esta experiencia se realizó en el Colegio Nuestra Señora de Guadalupe. El proceso educativo debe ser continuo, para facilitar la formación de una persona autónoma, trabajamos coordinadamente con vistas a la inserción de los alumnos provenientes del Nivel Medio en forma no traumática en aquellas Facultades de la Universidad Nacional del Litoral, en las cuales Matemática y Química son áreas relevantes en los respectivos planes de estudio. La adquisición de aprendizajes significativos se realiza mediante la claridad informativa y la aplicación sistemática, graduada y diversa de los contenidos a situaciones cotidianas que profundizan la comprensión de los conceptos. La situación seleccionada para esta experiencia es un tema de mucha trascendencia, el tabaquismo, que permitió integrar los contenidos de Matemática, Química y Computación

Validating a Density Functional Theory Approach for Predicting the Redox Potentials Associated with Charge Carriers and Excitons in Polymeric Photocatalysts

We compare, for a range of conjugated polymers relevant to water-splitting photocatalysis, the predictions for the redox potentials associated with charge carriers and excitons by a total-energy ΔDFT approach to those measured experimentally. For solid-state potentials, of the different classes of potentials available experimentally for conjugated polymers, the class measured under conditions which are the most similar to those during water splitting, we find a good fit between the ionization potentials predicted using ΔB3LYP and those measured experimentally using photoemission spectroscopy (PES). We also observe a reasonable fit to the more limited data sets of excited-state ionization potentials, obtained from two-photon PES, and electron affinities, measured by inverse PES, respectively. Through a comparison of solid-state potentials with gas phase and solution potentials for a range of oligomers, we demonstrate how the quality of the fit to experimental solid-state data is probably the result of benign error cancellation. We discuss that the good fit for solid-state potentials in vacuum suggests that a similar accuracy can be expected for calculations on solid-state polymers interfaced with water. We also analyze the quality of approximating the ΔB3LYP potentials by orbital energies. Finally, we discuss what a comparison between experimental and predicted potentials teaches us about conjugated polymers as photocatalysts, focusing specifically on the large exciton-binding energy in these systems and the mechanism of free charge carrier generation

Monitoring urban heat island through google earth engine. Potentialities and difficulties in different cities of the United States

The aim of this work is to exploit the large-scale analysis capabilities of the innovative Google Earth Engine platform in order to investigate the temporal variations of the Urban Heat Island phenomenon as a whole. A intuitive methodology implementing a large-scale correlation analysis between the Land Surface Temperature and Land Cover alterations was thus developed. The results obtained for the Phoenix MA are promising and show how the urbanization heavily affects the magnitude of the UHI effects with significant increases in LST. The proposed methodology is therefore able to efficiently monitor the UHI phenomenon