The Electromagnetic Form Factor of the Kaon in the Light-Front Approach

The kaon electromagnetic form factor is calculated within a light-front constituent quark model (LFCQM). The electromagnetic components of the current are extracted from the Feynman triangle diagram within the light-front approach. We also obtain the electroweak decay constant and the charge radius for the kaon in the light-front approach. In this work, the kaon observables are calculated and a fairly good agreement is obtained with a very higher accuracy when compared with the experimental data.Comment: Paper with 4 pages, 1 figure, reference: XII HADRON PHYSICS Conference - to appear in AIP Conference Proceeding

Uma abordagem de infra-estrutura de chaves públicas para ambientes corporativos

Este trabalho visa o estudo dos padrões e definições de uma Infra-estrutura de Chaves Públicas (ICP) no modelo hierárquico e o desenvolvimento de um projeto de uma Infraestrutura de Chaves Públicas privada para ambientes corporativos, de forma a implantar uma política de segurança e prover um aplicativo com as funcionalidades necessárias para a utilização dessa infra-estrutura. O projeto abrange a criação de uma Autoridade Certificadora interna a uma empresa e a implantação de um aplicativo para efetivar o gerenciamento de chaves públicas e privadas e utilização das mesmas para criptografia assimétrica dos dados. Este trabalho irá prover integridade, autenticidade e não-repúdio às informações dentro de uma corporação, diminuindo os prejuízos relativos a algumas fraudes eletrônicas, aumentando a segurança na guarda e tráfego de informações e evitando o gasto de se contratar uma Autoridade Certificadora externa

Fontes de silício na indução de resistência a insetos-praga e no desenvolvimento de plantas de batata inglesa.

O controle de insetos-praga exclusivamente com inseticidas sintéticos ocasiona diversos efeitos colaterais. A indução de resistência de plantas é uma estratégia em potencial para prevenir danos de insetos na cultura. Os objetivos deste trabalho foram avaliar os efeitos de fontes de silício na indução de resistência aos principais insetos-praga, no desenvolvimento e produtividade da cultura de batata inglesa em cultivo orgânico. As plantas foram submetidas aos seguintes tratamentos: 1- adubação via solo com agrosilício na dosagem correspondente a 8 t/ha; 2- adubação foliar com solução de ácido silícico a 0,8%; 3- adubação foliar com solução de cinza de eucalipto a 5% e 4- testemunha. As avaliações dos insetos-praga foram realizadas aos 20, 40 e 60 dias após a emergência das plantas, contando-se o número de pulgões, injúrias foliares provocadas por Diabrotica spp. e folíolos minados por Liriomyza spp. Foi determinado a altura, o diâmetro e a produtividade, bem como os teores de tanino e lignina das plantas. O ácido silícico atuou como indutor da síntese de tanino na planta e a cinza e o agrosilício agiram como promotores do desenvolvimento vegetativo das plantas

LINEAR PROGRAMMING APPLIED TO FINANCE - BUILDING A GREAT PORTFOLIO INVESTMENT

The stock market has grown steadily in recent years, and several indices have also been created in this market, like IGC, ISE and IBOVESPA. Thinking about this market growth, this paper aims to build an optimal portfolio using linear programming, based on companies simultaneously present in the indices: IGC and ISE. The constraints of the problem will be based on indicators of IBOVESPA. The model will be created to meet the restrictions set and to maximize the portfolio return, always comparing with the return of IBOVESPA, with a time horizon from 2007 until 2012. As results, the developed model was capable to provide better returns in fourteen of the twenty two periods under consideration. Besides, the average return considering all the periods was 0,03404 for the proposed model and -0,02086 for the IBOVESPA portfolio

Electromagnetic Structure of the Pion

In this work, we analyze the electromagnetic structure of the pion. We calculate its electromagnetic radius and electromagnetic form factor in low and intermediate momentum range. Such observables are determined by means of a theoretical model that takes into account the constituent quark and antiquark of the pion within the formalism of light-front field theory. In particular, we consider a nonsymmetrical vertex in this model, with which we calculate the electromagnetic form factor of the pion in an optimized way, so that we obtain a value closer to the experimental charge radius of the pion. The theoretical calculations are also compared with the most recent experimental data involving the pion electromagnetic form factor and the results show very good agreement.Comment: Paper with 4 pages, 1 figure, presented in XII HADRON PHYSICS Conference - to appear in AIP Conference Proceeding

What drives the allocation of motorways? Evidence from Portugal’s fast-expanding network

This study investigates the factors that influenced the allocation of motorways across municipalities in mainland Portugal over the period from 1981 to 2011. Our analysis, based on Poisson Pseudo-maximum Likelihood models, suggests that population size and market potential in 1981 are important determinants of motorway density in 2011. Likewise, physical and geographical variables also help explain the spatial distribution of motorway investment, as terrain ruggedness, distance to the coast, and distance to the border with Spain are negatively associated with motorway density. In addition, we consider the influence of the proximity to historical and pre-existing transport networks on the allocation of motorways; we find that municipalities that are closer to the 1800’s itineraries, the main roads of the 1945’s National Road Plan, and 1981’s train stations appear to have higher motorway densities in 2011, but this effect is concentrated in the vast and sparsely populated area of the country that excludes what we term the highdensity Portuguese “blue banana”. Interestingly, it is also only in this low-density region that partisan alignment between the municipal and the national levels of government appears to affect the allocation of transport investment, which suggests that motorways are more of a political asset in more remote or less urbanised areas.info:eu-repo/semantics/publishedVersio

Pandemic impacts in Natal, one of the main tourist destinations in Brazil

The coronavirus has impacted different sectors of society. The national and regional economy were highly weakened. In the state capital alone, around 300 companies closed in 2020. More than 87% of events in the same year were cancelled. Tourists visiting Natal / RN decreased sharply and this meant that hotels, bars, restaurants, and other activities had to suffer losses that had never occurred. This scientific article was carried out from studies that showed the impacts of the pandemic period on the Natal economy, found in statistical data from research institutes that demonstrated, in numbers, the economic losses of the tourism sector. These data served as the basis for the theoretical foundation of the analysis of several authors on the subject that, in this bibliographical, documentary and quali-quantitative research, showed different results. Among them, the need for solid and robust public policies for the reheating of the sector in 2021, when the prospects are for a decrease in the unemployment rate and an increase in financial assets, both fundamental for Brazil\u27s GDP

What drives the allocation of motorways? Evidence from Portugal's fast-expanding network

This study investigates the factors that influenced the allocation of motorways across municipalities in mainland Portugal. Our analysis, based on Poisson Pseudo-maximum Likelihood models, suggests that population size and market potential in 1981 are important determinants of motorway density in 2020. Physical and geographical variables also help explain the spatial distribution of motorway investment, as terrain ruggedness and distance to the coast are negatively associated with motorway density. In addition, we consider the influence of the proximity to historical and pre-existing transport networks on the allocation of motorways; we find that municipalities that are closer to 1800's itineraries, the main roads of the 1945's National Road Plan, and 1981's train stations appear to have higher motorway densities in 2020, but this effect is concentrated in the vast and sparsely populated area of the country that excludes what we term the high-density Portuguese “blue banana”. Interestingly, it is also only in this low-density region that partisan alignment between the municipal and the national levels of government appears to affect the allocation of transport investment, which suggests that motorways are more of a political asset in more remote or less urbanised areas.info:eu-repo/semantics/publishedVersio