Institucionalização de estruturas e processos de TI : uma análise das pressões isomórficas que podem influenciar o processo de institucionalização da TI de um órgão do judiciário brasileiro

Orlikowski e Barley (2001) apontam a importância da pesquisa em TI sob a ótica dos Estudos Organizacionais, principalmente quando é utilizada a análise neoinstitucional, porque dessa forma há uma compreensão mais sistêmica sobre como a tecnologia está entrelaçada nas complexas redes interdependentes, sociais, econômicas e políticas. O estudo de caso ocorreu em um órgão do judiciário, onde foram obtidos dados por meio de entrevistas, que foram triangulados com uma pesquisa documental. A dissertação busca elucidar como pressões isomórficas podem influenciar estruturas e processos de TI recomendados pela legislação em vigor, de forma a contribuir para gestores de organizações públicas durante a definição de prioridades para a TI. Para analisar o estágio institucional utilizou-se a classificação proposta por Tolbert e Zucker (1996) e como resultado, apesar das pressões isomórficas coercitivas, obteve-se que poucas estruturas e processos se institucionalizaram totalmente e, aparentemente, só aquelas que traziam com si outros tipos de pressões isomórficas é que parecem ter maior chance de chegar ao último estágio institucional. Foi constatada que a organização, durante o processo de institucionalização, pode incorrer em novas falhas, gerando mitos burocráticos e ritos cerimoniais que por exemplo, podem causar maior descolamento da preocupação por efetividade em seus resultados. Para determinados problemas, apontados durante as entrevistas, não foi possível encontrar influência de nenhuma pressão isomórfica. Tal fato sugere que a teoria neoinstitucional não conseguiu explicar todo o cenário da organização.

The Main Determinants of the Use of the Cost Accounting System in Portuguese Local Government

This paper explores the main determinants of the use of the cost accounting system (CAS) in Portuguese local government (PLG). Regression analysis is used to study the fit of a model of accounting changes in PLG, focused on cost accounting systems oriented to activities and outputs. Based on survey data gathered from PLG, we have found that the use of information in decision-making and external reporting is still a mirage. We obtain evidence about the influence of the internal organizational context (especially the lack of support and difficulties in the CAS implementation) in the use for internal purposes, while the institutional environment (like external pressures to implement the CAS) appears to be more deterministic of the external use. Results strengthen the function of external reporting to legitimate the organization’s activities to external stakeholders. On the other hand, some control variables (like political competition, usefulness and experience) also evidence some explanatory power in the model. Some mixed results were found that appeal to further research in the future. Our empirical results contribute to understand the importance of interconnecting the contingency and institutional approaches to gain a clear picture of cost accounting changes in the public sector.

Capital Intelectual: sua divulgação no setor bancário em Portugal

The importance of intangible resources has increased dramatically in recent years comparing to tangible ones. The economy in which we live is the result of competitive pressures that have imposed the implementation of business at an international level as well as a requirement in the application of sophisticated technologies that allow us to follow this fast evolution. In this age of information and innovation organizations will only survive if they are inserted in a global network of strategic relations, generically called as the network economy by Lev (2003). The service sector has stood out against the more traditional sectors of the economy. The intensive use of knowledge and a strong customer orientation created a new reality in today’s organizations: a growing importance attached to innovation, to the quality of products and services offered, to the information and communication technologies adopted, and to the creativity and particular abilities of human resources. The concept of intangible assets is more common in an accounting language and intellectual capital is most often applied in the context of management, being associated with a more comprehensive, multidimensional approach, representing all the knowledge that the institution owns and that it applies in the form of expertise, the creativity and organizational competencies that lead to innovation and to the sustained attainment of future economic benefits. An analysis of the scope of intellectual capital is fundamental to take more appropriate management decisions so that a more appropriate accounting treatment could be given by the accounting standardization organizations. This study intends to analyse the practices of information disclosure of the intellectual capital in the banking sector in Portugal, complementing the analysis of the disclosure of intangible assets in the context of accounting standards with the disclosure of intellectual capital in the context of organizational management. In particular, our main aims are to identify the extent of disclosure of intellectual capital made by banks in Portugal and also to identify the factors that determine such a disclosure. The disclosure in the context of accounting standards will be studied by checking the disclosure of intangible assets through the items listed in the International Accounting Standard 38 developed by the International Accounting Standards Board. The context of management was analysed by means of creating a voluntary disclosure index based on assumptions of the model Intellectus, developed by the Centro de Investigación sobre la Sociedad del Conocimiento – Instituto de Administración de Empresas (CIC-IADE) of the Universidad Autónoma of Madrid, and of the model Intellectual Capital Statement (made in Europe) (InCaS), both promoted by the European Commission and that we have adapted to the banking sector. When analysing the disclosure of intangible assets based on the context of accounting standards and the voluntary disclosure of intellectual capital, this study has tried to raise awareness about the importance of issuing reports on the intellectual capital as an alternative tool to take management decisions in the existing organizations and reflects the transparency and legitimacy that these institutions seek through a more extensive and more detailed information disclosure of their intellectual capital. Based on a complimentarily of economic theories, together with social and political theories, we tried to check the extent, evolution and tendencies of the compulsory disclosure of intangible assets and of the voluntary disclosure of the intellectual capital analysed in the period 2001-2011. Banks characteristics were also analysed in order to deduce those factors that determine or promote a larger disclosure in this sector. Based on these objectives, we adopted a longitudinal approach to explore the extent and the development of the disclosure of intangible assets as well as the factors that have determined it. Furthermore, we sought to assess the impact of the adoption of IAS 38 in the financial statements of the organizations in this sector. The disclosure index created on the basis of the disclosure requirements stated in IAS 38 from IASB was applied to the consolidated financial statements of the seventeen banks that rendered their statements in Portugal from 2001 to 2009. Since the information disclosed in the context of accounting standards may not have an important role as a management tool once it was not able to reflect what really contributes to the competitiveness and organizational growth, the voluntary disclosure of the intellectual capital was analysed according to the information obtained from the 2010 annual individual reports of the banks operating in Portugal in that year and from their respective websites in 2011. We tried to analyse the extent of the voluntary disclosure of the intellectual capital and of each of its components, human capital, structural capital and relational capital. The comparative analysis of their annual reports and their web pages allowed us to assess the incidence of the disclosure and discover what channel the banking sector focuses on when disclosing their intellectual capital. Also in this analysis the study of the disclosure determinants has allowed us to conclude about the influence of particular characteristics in the voluntary disclosure of the intellectual capital. The results of the analysis to the extent of the disclosure of intangible assets in the consolidated financial statements of the banking groups in Portugal in the period 2001-2009 have shown an average information disclosure of 0.24. This information disclosure evolved from an average value of 0.1940 in 2001 to 0.2778 in 2009. The average value is 0.8286 if it is only considered the disclosure of the intangible assets that the banks possessed. The evolution of this index means an increase in the average disclosure from 0.7852 in 2001 to 0.8788 in 2009. From the first results that are related to the extent of the disclosure of intangible assets in the financial statements, we can verify that the banking groups present a low disclosure level of these resources. However, when considering the disclosure of only the intangible assets that each institution owns, the disclosure level appears to be in compliance with the disclosure requirements for this sector. An evolution in the disclosure of intangible assets for the period considered was confirmed, showing an increase in the information disclosure of intangible assets in 2005, the year in which the accounting rules for intangible assets changed. The analysis that focused on the disclosure in the context of management tried to understand the extent, the incidence and the determinants of the voluntary information disclosure of intellectual capital in the annual reports of 2010 and on their web pages in 2011, studying the 32 banks operating in Portugal in this period. The average voluntary disclosure of the intellectual capital in the 2010 annual reports is 0.4342 while that in web pages is 0.2907. A review of the components of the intellectual capital allowed us to assess the importance that the banks confer to each of these components. The data obtained show that the relational capital, and more specifically the business capital, is the most disclosed component by banks in Portugal both in the annual reports and in their institutional web pages, followed by the structural capital and, finally, by the human capital. The disclosure of the human capital and the structural capital is higher in the annual reports than that in the websites, while the relational capital is more disclosed in the websites than in the annual reports. The results have also shown that the banks make a complementary use of both sources when disclosing information about their structural capital and relational capital but they do not show any information about their human capital in their websites. We tried to prove the influence of factors that could determine the accounting disclosure and the voluntary disclosure of the intellectual capital in this sector. The change in the IASB accounting rules as from January 1st 2005 gave a greater disclosure of accounting information of intangible assets in the financial statements of banks. The bank size and corporate governance measures have statistically proved to have an influence on the extent of the accounting disclosure of intangible assets and on the voluntary disclosure of the intellectual capital. Economic and financial variables such as profitability, operating efficiency or solvency were not determinants of information disclosure. The instability that the banking sector has experienced in economic and financial indicators in recent years as a result of the global financial markets imbalance has worsen indicators such as profitability, efficiency and solvency and caused major discrepancies in the economic situation between banks in Portugal. This empirical analysis has contributed to confront the disclosure required by accounting rules performed in the financial statements of organizations with that performed in the main disclosure media which is available for entities and which is increasingly requested in the process of taking management decisions. It also allowed us to verify whether there is homogeneity between institutions in the fulfilment of the requirements for information disclosure of intangible assets. However, as for voluntary disclosure of intellectual capital, there are large disparities in the disclosure extent between organizations. Regardless of this sector specific characteristics, the voluntary disclosure of intellectual capital made by banks in Portugal follows the trends in other sectors and the practices adopted in other countries, namely regarding the amount of information disclosed, the incidence of the disclosure on the indicators of relational capital and the importance of variables such as size as determinants of disclosure of intellectual capital. For a further knowledge in this field, we created a specific index for the banking sector, considering appropriate indicators for an incisive, comprehensive analysis in order to consider the most relevant indicators of intellectual capital components. Besides, confronting the analysis of disclosure in the context of accounting standards with the study of voluntary disclosure brought a new analysis approach to the research on intellectual capital disclosure. With this study, we have also intended to raise greater awareness of the need for harmonization in the intellectual capital disclosure on the part of the regulatory banking authority by means of a demanding, consistent and transparent report of intellectual capital with simple, clear, objective indicators so that those interested in disclosing intellectual capital information in the organizations in this sector may obtain more harmonized and comparable information. A research on the disclosure quality of intellectual capital, together with the application of other analysis methodologies in this sector, might be a promising approach for future research. Applying the voluntary disclosure index to the same sector in other countries may also contribute to the knowledge of disclosure practices in different geographical environments. We highlight the relevance of further studies contributing to the harmonization and consistency in the presentation of an intellectual capital report so as to enable organizations to disclose the resources that contribute most to their competitiveness and growth.

The international harmonization process of public accounting in Portugal: the perspective of different stakeholders

This paper investigates the reform of public accounting in Portugal through the IPSAS adoption highlighting the perception of different stakeholders. Two competing theories (NPM and the institutional theory) are used to understand public accounting changes within the Portuguese context. In general, different stakeholders agree with the favorable moment and the context of the reform. The context of financial crises and the great external pressures to cut public deficits and to improve the quality of financial information seem to be the most important factors to stimulate changes in public accounting. In addition, stakeholders recommend the use of different strategies to ensure success.

Use of performance information by local politicians: a field study in the Portuguese context.

This paper seeks to investigate the use of performance information by politicians and whether the institutional reforms on performance management (PM) have been operationalized by local politicians. Differences on the policy field and the organizational context have been analyzed. Our goal is contribute to knowledge on PM in the political sphere and understand the different responses of politicians to government change initiatives (mainly coercive pressures). Our findings show that local politicians support the notion that greater attention should be devoted to the use of performance information on the evaluation process. Nevertheless they are very skeptic in relation to effective execution of government reforms. There is an internal culture where agencies are embedded, strongly influenced by the high degree of politicisation among senior managers, that lead politicians to be more concerned about personal opinions and informal performance information rather than to use more sophisticated information (output and outcome measures). The institutional approach helps us to identify political responses to institutional pressures and understand the reasons for a reduced use in the Portuguese context.

The internationally standardized process of public accounting: the perspective of different stakeholders in Portugal

New Public Management (NPM) led to great pressures for to introduce and adapt businesslike accounting in the public sector (Hood, 1995; Lapsley, 2008; Lapsley et al., 2009), specially the transition from cash basis to accrual-based accounting. In consequence, since the last 20 years we assist to a movement towards internationally standardized of public sector accounting that led to the publication of 32 International Public Sector Accounting Standards (IPSAS) for all public sector entities from national central governments to local governments (IFAC, 2008). These standards are accrual-basis and they emphasize the balance sheet approach, the fair value measurement and the revenue-expense approach (Hints, 2007). The main innovations are associated with the use of the balance sheet approach and the fair value measurement because, traditionally, public accounting systems are mainly focused on the revenue-expense approach and on historical cost valuation (Oulasvirta, 2014).

Performance management framework: the fit between PM framework adopted in Portuguese local government and the Otley’s framework

Purpose/objectives: This paper seeks to investigate whether performance management (PM) framework adopted in Portuguese local government (PLG) fit the Otley’s PM framework (1999). In particularly, the research questions are (1) whether PM framework adopted in PLG (SIADAP) fit the Otley´s framework, and (2) how local politicians (aldermen) see the operation of performance management systems (PMS) in PLG (focusing on the goal-setting process and incentive and reward structures). Theoretical positioning/contributions: With this paper we intend to contribute to literature on how the Otley’s PM framework can guide empirical research about the operation of PMS. In particular, the paper contributes to understand the fit between PMS implemented in PLG and the Otley´s PM framework. The analysis of this fit can be a good contribution to understand if PMS are used in PLG as a management tool or as a strategic response to external pressures (based on interviews conducted to aldermen). We believe that the Otley’s PM framework, as well as the extended PM framework presented by Ferreira and Otley (2009), can provide a useful research tool to understand the operation of PMS in PLG. Research method: The first research question is the central issue in this paper and is analyzed based on the main reforms introduced by Portuguese government on PM of public organizations (like municipalities). On the other hand, interviews conducted on three larger Portuguese municipalities (Oporto, Braga, and Matosinhos) show how aldermen see the operation of PMS in PLG, highlighting the goals setting process with targets associated and the existing of incentive and reward structures linked with performance. Findings: Generally we find that formal and regulated PM frameworks in PLG fit the main issues of the Otley’s PM framework. However, regarding the aldermen perceptions about PMS in practice we find a gap between theory and practice, especially regarding difficulties associated with the lack of a culture of goals and targets setting and the lack of incentive and reward structures linked with performance.

Contemporary issues in the government and administration of Latin American megacities

This paper is the first to systematically analyze and compare the structures of city governance and administration for seven major cities in Latin America, four of which are megacities (population of over 10 million), and three others are large national capitals. U.S. and U. K. models of city administration are reviewed as baseline models against which differences in Latin American may be explored. Structures of Government in Latin America show several important features and trends: 1) the lack of metropolitan (cross jurisdictional) authority; 2) the existence of strong mayors and weak councils"; 3) high levels of partisanship; 4) overlapping rather than interlocking bureaucracies; 5) pressures towards the privatization of city services, but continuing tension over the desirability of public versus private control; 6) greater fiscal responsibility and autonomy; and 7), a continuing marginalization of public participation in megacity governance.In spite of these features, many cities throughout the region (regardless of whether they are megacity size or national capitals), are actively intensifying their efforts to develop more effective, accountable and democratic governance structures.

Ler em tempo livre durante o Estado Novo: A função do suplemento infantil Pim-Pam-Pum na formação da criança

RESUMO: Esta dissertação tem como objectivo compreender a influência da ideologia do Estado Novo nos conteúdos inseridos no suplemento infantil Pim-Pam-Pum. Visa ainda relacionar, num determinado momento temporal o suplemento infantil de um dos jornais mais lidos da época O Século, com a ideologia do Estado Novo. Procura identificar os valores incutidos nos números a analisar no Pim-Pam-Pum num período de dois anos. O período histórico em análise do suplemento infantil Pim-Pam-Pum compreende os exemplares entre 1953 a 1955. Como principais conclusões do estudo retira-se que o suplemento infantil procurava educar o seu público de forma lúdica. Por outro lado, transmitia e incutia em colaboração com a família os principais valores salazaristas. A imprensa escrita passa a ser uma arma de propaganda ideológica do Estado Novo numa tentativa de conter informação desfavorável ao regime perante as pressões internas e externas. Com a institucionalização da censura após a segunda Guerra Mundial, a vigilância e o exame das publicações dos organismos competentes em colaboração com a própria auto-censura dos jornalistas, simplificou-se. No entanto a imprensa procurou cumprir com a sua missão de divulgação cultural e lúdica através de jornais diários, revistas e suplementos infantis. ABSTRACT:The aim of this dissertation is to understand the influence of the ideology of the "Estado Novo" in the contents inserted in the children's supplement Pim-Pam-Pum. It also aims to relate, in a certain historical period, the children’s supplement of one of the most important newspapers of the time, "O Século", with the ideology of the "Estado Novo". In addition, it intends to identify the values ingrained in the numbers to be analysed in Pim-Pam-Pum in a period of two years. The period under analysis of the children's supplement Pim-Pam-Pum includes the numbers from 1953 to 1955. One of the main conclusions of this study is that the children's aforementioned supplement aimed to educate its audience in a joyful manner. On the other hand, it transmitted as well as inculcated with the families’ collaboration the main Salazarist values. The press becomes a weapon of ideological propaganda of the "Estado Novo" in an attempt to keep harmful information to the regime from the internal and external pressures. With the institucionalization of censorship after the Second World War, the careful surveillance of publications by the competent and relevant organisms in collaboration with the censorship made by the journalists themselves, was simplified. However, the press tried to accomplish its mission of cultural and playful diffusion by means of newspapers, magazines and children's supplements.

Possible consequences of increasing life expectancy in Brazil: the perspective of a European historical demographer

Those over sixty years of age accounted for 6.6% of the total population of Brazil in 1985, in the Federal Republic of Germany this proportion was 20.3% in 1984. As early as 1950 it had been 14.5%. This proportion will not even be reached in Brazil in the year 2000 when persons aged sixty years and older are only projected to make up 8.8% of the total population. Similarly, in 1982/84 life expectancy at birth in the Federal Republic was 70.8 years for men and 77.5 for women; in Brazil the figures for 1980/85 were, by contrast, "only" 61.0 and 66.0. Against this background it is easy to understand why the discussion concerning an ageing society with its many related medical, economic, individual and social problems has been so slow in coming into its own in Brazil. As important as a more intensive consideration of these aspects may be in Brazil at present, they are, nevertheless, only one side of the story. For a European historical demographer with a long-term perspective of three of four hundred years, the other side of the story is just as important. The life expectancy which is almost ten years lower in Brazil is not a result of the fact that no one in Brazil lives to old age. In 1981 people sixty-five years and older accounted for 34.4% of all deaths! At the same time infants accounted for only 22.1% of total mortality. They are responsible, along with the "premature" deaths among youths and adults, for the low, "average" life expectancy figure. In Europe, by contrast, these "premature" deaths no longer play much of a role. In 1982/84 more than half of the women (52.8%) in the Federal Republic of Germany lived to see their eightieth birthdays and almost half of the men (47.3%) lived to see their seventy-fifth. Our biological existence is guaranteed to an extent today that would have been unthinkable a few generations ago. Then, the classic troika of "plague, hunger and war" threatened our forefathers all the time and everywhere. The radical transition from the formerly uncertain to a present-day certain lifetime, which is the result of the repression of "plague, hunger and war", led to unexpected consequences for our living together. Our forefathers were forced to live in closely knit Gemeinschaften in the interest of physical survival and to subordinate their egoistic goals to a common value, but now these pressures have, for the most part, fallen away. Correspondingly, this much more certain EGO has taken center stage. An ever greater number of us chooses to live life as single beings: the number of marriages is lower every year; the number of divorces is on the increase; in Berlin (West) more than half (sic! 52.3%) of all households are already composed on only one person. For the last dozen years the annual number of births in the Federal Republic has been insufficient to ensure population replacement. Not a population explosion but rather the opposite, a population implosion, is our problem. Human beings do not appear to be "social animals", as was axiomatically assumed for so long. They were only forced to behave as such for as long as "plague, hunger and war" forced them to do so. When these life endangering conditions no longer exist and life becomes certain even without their being integrated into a Gemeinschaft then humans suddenly show themselves more and more to be independent single beings. It is not the percentage of the population that is over sixty or sixty-five that is decisive in this context but rather how certain adults perceive their biological lives to be, since they are the ones who organize their lives, who build communities or who are ever more often willing only to enter into means-to-an-end personal unions without lasting or close ties and mutual responsibilities. There are many signs which seem to point to a development in this direction in Brazil as well. More and more adults in Brazil are caught up in the deep-seated transition from an uncertain to a certain lifetime. A third of them die after having reached their sixty-fifth birthday. It therefore seems to me to be high time that one began to give more consideration to the other side of the story in Brazil as well. And who is more suited intensively to consider the long-term perspectives than those engaged in the public health sector in whose competence, after all, such aspects, as "life certainty", "life expectancy" and "age at death" belong?

Supercritical CO2 extraction of secondary metabolites from Agaricus blazei: experiments and modelling

The mycelium and young fruiting bodies of Agaricus blazei were submitted to supercritical CO2 extraction, in a modified commercial flow apparatus, at temperatures from 40 to 80 ºC, pressures up to 600 bar and CO2 flow-rates from 2.0 to 9.0 g.min-1. The best extraction conditions of secondary metabolites, whereby the degree of solubilization (g extract/100 g of fungi) is the highest, was obtained with pure CO2 at 400 bar, 70 ºC and a CO2 flow rate of 5.7g.min-1. The extract in that conditions were analysed by GC-Ms. In order to increase the extraction yield of secondary metabolites, which are mostly present in glycolipid fractions, a polar compound (ethanol) was used as co-solvent in the proportions of 5 and 10 % (mol/mol). The presence of ethanol increased the yield when compared with the extraction with pure CO2. Moreover, a simple model was applied to the supercritical CO2 extraction of secondary metabolites from Agaricus blazei.

Esforços hidrodinâmicos em comportas verticais (Downpull)

O downpull é uma força gerada pelo efeito do escoamento em comportas planas com estanquidade a jusante e pode condicionar, de forma determinante, o dimensionamento do órgão de manobra e a preponderância de fecho de uma comporta vertical em condições de emergência. Neste trabalho é desenvolvido um modelo de cálculo analítico para a obtenção do downpull e um modelo de simulação numérica com Computational Fluid Dynamics (CFD). O modelo analítico desenvolvido foi exposto numa folha de cálculo e permite a obtenção de resultados em poucos minutos, factor essencial sob o ponto de vista económico. O modelo em CFD tem como principal objectivo a validação do modelo analítico. Sendo um modelo mais complexo e dispendioso em termos de tempo despendido, apenas poderá ser utilizado em situações pontuais que exijam um maior rigor nos resultados obtidos.

Os desafios da qualificação profissional pós-secundária não-superior (nível 4) para a inovação empresarial no contexto da União Europeia e dos países da OCDE

A maioria das nações mais desenvolvidas deve, em larga medida, a sua prosperidade à produtividade da sua força de trabalho. Esta produtividade relaciona-se, fundamentalmente, com dois aspectos essenciais. Por um lado, com o nível e adequação das qualificações e competências da população activa, as quais permitem desenvolver o empreendedorismo e criar riqueza e, por outro, com a qualidade e grau de sofisticação dos equipamentos, tecnologias, modelos de organização e sistemas de gestão de que as empresas dispõem. Nesta comunicação, elaborada por convite para apresentação na sessão comemorativa do 20º aniversário da AFTEM, no Porto, após a contextualização das exigências do mercado de trabalho em resultado da inovação empresarial e da emergência das economias baseadas no conhecimento, apresentam-se alguns estudos recentemente concluídos em diversos países e regiões da OCDE, nomeadamente, Austrália, Irlanda, Reino Unido e Escócia – nos quais se foca a necessidade de incrementar o nível de qualificações para responder às necessidades do tecido produtivo por forma a manter a competitividade da indústria e serviços desses países e regiões à escala global; em particular realça-se a importância de se aumentar a percentagem de população activa com nível 4 de qualificação profissional. Aborda-se, ainda, a situação da formação pós secundária não superior em Portugal (nível 4). Conclui-se, formulando algumas recomendações em termos de estratégias e de trabalho futuro com vista a dinamizar as oportunidades de qualificação de nível 4, em estreita articulação com as empresas, como forma de o tecido produtivo nacional dispor de níveis de qualificação de recursos humanos que permitam a mobilidade para novas actividades com maior valor acrescentado e, por esta via, atingir níveis de rentabilidade semelhante à dos restantes estados membros da UE e de outros países da OCDE.

Compact Stars and Magnetized CFL Matter

The stability of the color flavor locked phase in the presence of a strong magnetic field is investigated within the phenomenological MIT bag model. It is found that the minimum value of the energy per baryon in a color flavor locked state at vanishing pressure is lower than the corresponding one for unpaired magnetized strange quark matter and, as the magnetic field increases, the energy per baryon decreases. This implies that magnetized color flavor locked matter is more stable and could become the ground state inside neutron stars. The anisotropy of the pressures is discussed. The mass-radius relation for such stars is also studied.

Effect of the number of shells on the pressure and energy of two-dimensional free bubble clusters

We have performed Surface Evolver simulations of two-dimensional hexagonal bubble clusters consisting of a central bubble of area lambda surrounded by s shells or layers of bubbles of unit area. Clusters of up to twenty layers have been simulated, with lambda varying between 0.01 and 100. In monodisperse clusters (i.e., for lambda = 1) [M.A. Fortes, F Morgan, M. Fatima Vaz, Philos. Mag. Lett. 87 (2007) 561] both the average pressure of the entire Cluster and the pressure in the central bubble are decreasing functions of s and approach 0.9306 for very large s, which is the pressure in a bubble of an infinite monodisperse honeycomb foam. Here we address the effect of changing the central bubble area lambda. For small lambda the pressure in the central bubble and the average pressure were both found to decrease with s, as in monodisperse clusters. However, for large,, the pressure in the central bubble and the average pressure increase with s. The average pressure of large clusters was found to be independent of lambda and to approach 0.9306 asymptotically. We have also determined the cluster surface energies given by the equation of equilibrium for the total energy in terms of the area and the pressure in each bubble. When the pressures in the bubbles are not available, an approximate equation derived by Vaz et al. [M. Fatima Vaz, M.A. Fortes, F. Graner, Philos. Mag. Lett. 82 (2002) 575] was shown to provide good estimations for the cluster energy provided the bubble area distribution is narrow. This approach does not take cluster topology into account. Using this approximate equation, we find a good correlation between Surface Evolver Simulations and the estimated Values of energies and pressures. (C) 2008 Elsevier B.V. All rights reserved.