Structure and form of the solutions of the Erdos-Straus conjecture

In this paper we classify certain values of p that satisfy the Erdos-Straus conjecture, concerning the decomposition of fractions of the form 4/n as sum of three fractions with numerator identically equal to 1, not according to their modular similarity but to the fact that they share solutions with identical structure. We classify all solutions that satisfy that they are of the form (du,dv,duv) and find characterizations for values of p that were initially difficult to classify, such as p=1009. We also study the solutions (x,y,z) that satisfy that gcd(x,y,z)=x and, finally, we classify all the cases in which any of these two variables coincide with each other.Comment: 13 page

On welfare criteria and optimality in an endogenous growth model

In this paper we explore the consequences for optimality of a social planner adopting two different welfare criteria. The framework of analysis is an OLG model with physical and human capital. We first show that, when the SWF is a discounted sum of individual utilities defined over consumption per unit of natural labour, the precise cardinalization of the individual utility function becomes crucial for the characterization of the social optimum. Also, decentralizing the social optimum requires an education subsidy. In contrast, when the SWF is a discounted sum of individual utilities defined over consumption per unit of efficient labour, the precise cardinalization of preferences becomes irrelevant. More strikingly, along the optimal growth path, education should be taxed.endogenous growth, human capital, intergenerational transfers, education policy

Employment descentralisation: polycentric compaction or sprawl? The case of the Barcelona Metropolitan Region 1986-1996

The Barcelona Metropolitan Region (BMR) has been repeatedly characterised as a polycentric-type urban system. The aim of this study is to corroborate this affirmation by making use of a methodology that enables the identifying of employment subcentres and valuing of the degree of polycentrism of the BMR in 1986 and 1996. The results obtained in the two years confirm the existence and extension of the polycentrism.Employment subcentres, identification, descentralisation, sprawl, compaction, polycentrism.

Picosecond third-order nonlinearities in metal-complexed PDA's and all-optical switching potentiality in Fabry-Perot devices containing poly-DCHD

Abstract unavailable please refer to PD

Does Indirect Tax Harmonization Deliver Pareto Improvements in the Presence of Global Public Goods?

This paper identifies conditions under which, starting from any tax distorting equilibrium, destination- and origin-based indirect tax-harmonizing reforms are potentially Pareto improving in the presence of global public goods. The first condition (unrequited transfers between governments) requires that transfers are designed in such a way that the marginal valuations of the global public goods are equalized, whereas the second (conditional revenue changes) requires that the change in global tax revenues, as a consequence of tax harmonization, is consistent with the direction of inefficiency in global public good provision relative to the (modified) Samuelson rule. Under these conditions, tax harmonization results in redistributing the gains from a reduction in global deadweight loss and any changes in global tax revenues according to the Pareto principle. And this is the case independently of the tax principle in place (destination or origin).origin principle, destination principle, indirect tax harmonization, reform of commodity taxes, global/local public goods

A facile method to prepare hexagonal molybdenum trioxide microrods

We report the successfully preparation of straight and well faceted hexagonal - MoO 3 rods by a simple method consisting o f a thermal treatment at low temperature applied to molybdenum diluited in a mixture of HCl and HNO 3. We have obtained sub-micrometer hexagonal rods several microns long with defect free walls. Electron scanning microscopy (SEM) and microRaman spectroscopy w ere used to characterize the obtained rods. ur results demonstrate the feasibility of synthesizing h-MoO 3 in a very simple way

Distance learning courses in engineering in the EU-27

The European Union is facing a scarcity of skilled professionals in the field of nuclear energy, especially at the higher educational levels. This is mainly due to the worldwide reduction in public acceptance of everything nuclear in the aftermath of the Three Mile Island and Chernobyl accidents, occurred in 1979 and 1986 respectively. These accidents have led to a decreased interest in nuclear education and thus to a “generational gap”, where the skilled nuclear workforce is on the verge of retirement or has already retired, and the new generation of nuclear workers does not have the numbers to cover the needs of the industry. The present report, commissioned by the CAPTURE Action of the Joint Research Centre of the European Commission, has the aim of complementing other European initiatives in the field of nuclear Education & Training by analyzing the availability of eLearning courses in nuclear and nuclear-related fields across the EU-27. This report gives an overview of the eLearning tools and frameworks available on the market and analyzes the main types of eLearning. A list of the eLearning courses offered by Universities in Europe is presented, along with contact details and websites (situation as of the15th of April 2013). An electronic version of the list of courses will be published on the CAPTURE website (http://capture.jrc.ec.europa.eu/), and it will be updated every six months.JRC.F.4-Nuclear Reactor Integrity Assessment and Knowledge Managemen

Evaluar la construcción de un pavimento rígido empleando una geomalla triaxial para su viabilidad técnica, económica e impacto ambiental en la av. circunvalación Túpac Amaru -Chaupimarca –Pasco

Esta investigación tiene como objetivo evaluar la construcción de un Pavimento rígido empleando una geomalla triaxial Tx-140 para su viabilidad técnica, económica e impacto ambiental en la Av. Circunvalación Túpac Amaru. En el distrito Chaupimarca provincia de Pasco y departamento de Pasco, tiene como objetivos específicos; determinar el aporte estructural que brinda una geomalla triaxial al pavimento rígido ,determinar los costos que se generan por la construcción de un pavimento rígido con geomalla triaxial y evaluar los impactos ambientales de este tipo de construcción, por tales motivos para poder determinar los espesores de pavimento rígido con y sin geomalla tx-140 se usó la método AASHTO-93 y la metodología Giroud Hand respectivamente; para determinar los costos se usó el Análisis de Precios Unitarios para las partidas de construcción y manteamiento con el fin de determinar el costo total de la construcción del pavimento con y sin refuerzo, finalmente se usó el manual del SEIA ( Sistema Nacional de Evaluación de Impacto Ambiental) para poder evaluar los impactos ambientales y tomar las medidas de control correspondientes para una construcción de pavimento rígido con geomalla triaxial, llegando a la conclusión que este tipo de pavimento usando esta tecnología (Geomalla triaxial Tx-140) trae beneficios estructurales, ya que la Tx-140 ayuda a confinar al material granular sobre la subrasante con sus aberturas triangulares aumentando la capacidad portante del suelo así como también reduce los costos e impactos ambientales