677 research outputs found
An inspection on the Borel masses relation used in QCD sum rules
In this work, we studied the Borel masses relation used in QCDSR
calculations. These masses are the parameters of the Borel transform used when
the three point function is calculated. We analised an usual and a more general
linear relations. We concluded that a general linear relation between these
masses provides the best results regarding the standard deviation.Comment: 6 pages, 2 figures, Prepared for 11th Hadron Physic
A QCD sum rules calculation of the strong coupling constant
In this work, we calculate the form factors and the coupling constant of the
strange-charmed vertex in the framework of the QCD sum rules
by studying their three-point correlation functions. All the possible off-shell
cases are considered, , and , resulting in three different
form factors. These form factors are extrapolated to the pole of their
respective off-shell mesons, giving the same coupling constant for the process.
Our final result for the coupling constant is .Comment: 17 pages, 4 figure
Aplicação de SAFe® a um Projecto de Manutenção de Aviões
Maintenance, repair and overhaul (MRO) operations have a great impact on the life cycle of an aircraft (A/C). MROs organizations address various challenges on planning activities to ensure the maximum reliability of an A/C, given the amount of unscheduled maintenance. Subcontracting MRO activities by airline companies, has been continuously increasing as an alternative of performing the heavy maintenance themselves, adding a constraint on this type of industries which is to manage the customer demands. Considering the main issues, it is required to select the most suitable approach to plan and manage A/C maintenance projects. Agile Project Management (PM) could be a solution to overcome the main difficulties in this sector, managing the uncertainty throughout the project, providing customer visibility and control over the service. This work arises in a real-life case of a subcontracted MRO program in a multinational A/C manufacture enterprise, which also suffers from significant challenges of planning and managing maintenance activities throughout the project life cycle. The program has experimented agile methodologies that revealed a positive impact. In order to the whole program embrace agility and overcome the identified main problems, it was proposed the usage of an elaborate and well-defined agile framework. Scaled Agile Framework for enterprises (SAFe®) is an online knowledge base that implements diverse agile techniques to support businesses, develop and deliver solutions, achieving business agility. As SAFe® was mainly developed for software industries, due to the characteristics of the project and the type of industry where it is inserted, the application of this framework needed to be customized. Accordingly to the particularities of the project, the most suitable PM approach is a hybrid approach, where initially the scope of the project is delineated, with a contingency plan, supported by SAFe® to manage the issues that arise throughout the project. The agile methodologies allow customer centred attention, more communication channels, and by iterating over the product, planning the unscheduled work focusing on high priority tasks. Lastly, a framework in the core of the appearance of the issues was developed, to define the interconnection between the whole SAFe® concepts and to provide an extended view of how the project will progress with the new approach.As operações de manutenção, reparação e revisão produzem grande impacto no ciclo de vida de uma aeronave. As organizações que operam neste setor enfrentam vários desafios no planeamento das atividades que garantem a máxima confiabilidade de uma aeronave, dada a quantidade de manutenção não programada. A subcontratação deste tipo de atividades, por parte das companhias aéreas, tem crescido continuamente como uma alternativa à realização da própria manutenção pesada, adicionando um constrangimento para este tipo de indústrias: gerir as exigências dos clientes. Considerando os principais problemas, é necessário selecionar a abordagem mais adequada para planear e gerir projetos de manutenção de aviões. A gestão ágil de projetos poderá ser uma solução para superar as principais dificuldades deste setor, gerindo as incertezas ao longo do projeto, proporcionando visibilidade ao cliente e controlo sobre o serviço. Este trabalho surge num caso real de um programa subcontratado numa empresa multinacional de fabrico de aviões, que também sofre de desafios significativos no planeamento e gestão de atividades de manutenção ao longo do ciclo de vida do projeto. O programa experienciou metodologias ágeis que revelaram um impacto positivo. Para que todo o programa adote a agilidade e supere os principais problemas identificados, foi proposto o uso de uma elaborada e bem definida estrutura ágil. O Scaled Agile Framework para empresas é uma base de conhecimento online que implementa diversas técnicas ágeis para apoiar as empresas no desenvolvimento e entrega de soluções, alcançando a agilidade nos negócios. O SAFe® foi desenvolvido principalmente para indústrias de software, devido à s caracterÃsticas do projeto e ao tipo de indústria em que está inserido, a aplicação desta estrutura necessitou de ser personalizada. De acordo com as particularidades do projeto, a abordagem de gestão de projetos mais adequada é uma abordagem hÃbrida, onde inicialmente o projeto é delineado, com um plano de contingência, apoiado pelo SAFe® para gerenciar os problemas que surgem ao longo do projeto. As metodologias ágeis permitem centrar a atenção no cliente, mais canais de comunicação e, ao iterar sobre o produto, planear o trabalho não programado com foco em tarefas de alta prioridade. Por fim, foi desenvolvido um framework no cerne do surgimento dos problemas, de forma a definir as interligações entre todos os conceitos do SAFe® e fornecer uma visão ampliada de como o projeto irá progredir com a nova abordagem
From Bargaining Solutions to Claims Rules: A Proportional Approach
Agents involved in a conflicting claims problem may be concerned with the proportion of their claims that is satisfied, or with the total amount they get. In order to relate both perspectives, we associate to each conflicting claims problem a bargaining-in-proportions set. Then, we obtain a correspondence between classical bargaining solutions and usual claims rules. In particular, we show that the constrained equal losses, the truncated constrained equal losses and the contested garment (Babylonian Talmud) rules can be obtained throughout the Nash bargaining solution.Financial support from Universitat Rovira i Virgili, Banco Santander and Generalitat de Catalunya under project 2011LINE-06, Ministerio de Ciencia e Innovación under project ECO2011-24200 and from the Spanish Ministry of Economy and Competitiveness under project ECO2013-43119 are gratefully acknowledged
An extremely rare association of multiple familial trichoepitheliomas and hereditary multiple osteochondromas
info:eu-repo/semantics/publishedVersio
Relations between theory of mind and academic school readiness: the moderating role of child gender
This study investigated the prospective relationship between preschoolers’ theory of mind (ToM) skills and academic school readiness, while exploring the possible moderator role played by child gender. The participants were 75 children who were assessed at two time points: when enrolled in the second preschool year (T1) and again 4 months before school entry (T2). The results showed an association between children's ToM abilities at T1 (but not at T2) and later academic readiness at T2, but only for girls, even after accounting for child IQ and maternal education. These findings support the idea that girls and boys can differ in how they use their ToM abilities in their daily life and highlight the relevance of further exploring gender-specific effects when investigating children's social cognition and school readiness.info:eu-repo/semantics/acceptedVersio
Chromium and zinc in a series of plants used in Portugal in the herbal treatment of non-insulinized diabetes
Chromium (Cr3+) and zinc (Zn2+) are essential micronutrients for humans. Chromium's main action is thought to be the regulation of blood sugar, because chromium deficiency is related with diabetic-like (type 2) symptoms, and chromium supplementation is associated with increased glucose tolerance and insulin sensitivity. Zinc supplementation also alleviates hyperglycaemia of the same type of diabetic patients contributing to improved insulin activity. Some Portuguese plants are commonly used as teas, alcoholic extracts or as powders by diabetic people and as medicines. Although their active principle is not yet known, the importance of their chromium and zinc content in the claimed therapeutic properties should not be disregarded. Thus, the determination of chromium and zinc in some Portuguese medicinal plants was performed by atomic absorption spectrophotometry. Almost all the analysed plants contain chromium and zinc at the normal level for these elements but many plants, which are used for the preparation of teas or other forms of remedies to help those type of diabetic patients, contain them in higher levels
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