The n-site approximation for the triplet-creation model

The nonequilibrium phase transition of the one-dimensional triplet-creation model is investigated using the n-site approximation scheme. We find that the phase diagram in the space of parameters (gamma, D), where gamma is the particle decay probability and D is the diffusion probability, exhibits a tricritical point for n >= 4. However, the fitting of the tricritical coordinates (gamma(t), D(t)) using data for 4 <= n <= 13 predicts that gamma(t) becomes negative for n >= 26, indicating thus that the phase transition is always continuous in the limit n -> infinity. However, the large discrepancies between the critical parameters obtained in this limit and those obtained by Monte Carlo simulations, as well as a puzzling non-monotonic dependence of these parameters on the order of the approximation n, argue for the inadequacy of the n-site approximation to study the triplet-creation model for computationally feasible values of n.

The mass media destabilizes the cultural homogenous regime in Axelrod`s model

An important feature of Axelrod`s model for culture dissemination or social influence is the emergence of many multicultural absorbing states, despite the fact that the local rules that specify the agents interactions are explicitly designed to decrease the cultural differences between agents. Here we re-examine the problem of introducing an external, global interaction-the mass media-in the rules of Axelrod`s model: in addition to their nearest neighbors, each agent has a certain probability p to interact with a virtual neighbor whose cultural features are fixed from the outset. Most surprisingly, this apparently homogenizing effect actually increases the cultural diversity of the population. We show that, contrary to previous claims in the literature, even a vanishingly small value of p is sufficient to destabilize the homogeneous regime for very large lattice sizes.

Tectonic fabric revealed by AARM of the proterozoic mafic dike swarm in the Salvador city (Bahia state): Sao Francisco Craton, NE Brazil

Magnetic fabric and rock magnetism studies were performed on 25 unmetamorphosed mafic dikes of the Meso-Late Proterozoic (similar to 1.02 Ga) dike swarm from Salvador (Bahia State, NE Brazil). This area lies in the north-eastern part of the Sao Francisco Craton, which was dominantly formed/reworked during the Transamazonian orogeny (2.14-1.94 Ga). The dikes crop out along the beaches and in quarries around Salvador city, and cut across both amphibolite dikes and granulites. Their widths range from a few centimeters up to 30 m with an average of similar to 4 m, and show two main trends N 140-190 and N 100-120 with vertical dips. Magnetic fabrics were determined using both anisotropy of low-field magnetic susceptibility (AMS) and anisotropy of anhysteretic remanent magnetization (AARM). The magnetic mineralogy was investigated by many experiments including remanent magnetization measurements at variable low temperatures (10-300 K), Mossbauer spectroscopy, high temperature magnetization curves (25-700 degrees C) and scanning electron microscopy (SEM). The rock magnetism study suggests pseudo-single-domain magnetite grains carrying the bulk magnetic susceptibility and AARM fabrics. The magnetite grains found in these dikes are large and we discard the presence of single-domain grains. Its composition is close to stoichiometric with low Ti substitution, and its Verwey transition occurs around 120 K. The main AMS fabric recognized in the swarm is so-called normal, in which the K(max)-K(int) plane is parallel to the dike plane and the magnetic foliation pole K(min)) is perpendicular to it. This fabric is interpreted as due to magma flow, and analysis of the K m inclination permitted to infer that approximately 80% of the dikes were fed by horizontal or sub-horizontal flows (K(max) < 30 degrees). This interpretation is supported by structural field evidence found in five dikes. In addition, based on the plunge of K(max), two mantle sources could be inferred; one of them which fed about 80% of the swarm would be located in the southern part of the region, and the other underlied the Valeria quarry. However, for all dikes the AARM tensors are not coaxial with AMS fabrics and show a magnetic lineation (AARM(max)) oriented to N30-60E, suggesting that magnetite grains were rotated clockwise from dike plane. The orientation of AARM lineation is similar to the orientation of a system of faults in which the Salvador normal fault is the most important. These faults were formed during Cretaceous rifting in the Reconcavo-Tucano-jatoba assemblage that corresponds to an aborted intra-continental rift formed during the opening of the South Atlantic. Therefore, the AARM fabric found for the Salvador dikes is probably tectonic in origin and suggests that the dike swarm was affected by the important tectonic event responsible for the break-up of the Gondwanaland. (C) 2008 Elsevier B.V. All rights reserved.

THE RIO APA CRATON IN MATO GROSSO DO SUL (BRAZIL) AND NORTHERN PARAGUAY: GEOCHRONOLOGICAL EVOLUTION, CORRELATIONS AND TECTONIC IMPLICATIONS FOR RODINIA AND GONDWANA

The Rio Apa cratonic fragment crops out in Mato Grosso do Sul State of Brazil and in northeastern Paraguay. It comprises Paleo-Mesoproterozoic medium grade metamorphic rocks, intruded by granitic rocks, and is covered by the Neoproterozoic deposits of the Corumbi and Itapocurni Groups. Eastward it is bound by the southern portion of the Paraguay belt. In this work, more than 100 isotopic determinations, including U-Pb SHRIMP zircon ages, Rb-Sr and Sm-Nd whole-rock determinations, as well as K-Ar and Ar-Ar mineral ages, were reassessed in order to obtain a complete picture of its regional geological history. The tectonic evolution of the Rio Apa Craton starts with the formation of a series of magmatic arc complexes. The oldest U-Pb SHRIMP zircon age comes from a banded gneiss collected in the northern part of the region, with an age of 1950 +/- 23 Ma. The large granitic intrusion of the Alumiador Batholith yielded a U-Pb zircon age of 1839 +/- 33 Ma, and from the southeastern part of the area two orthogneisses gave zircon U-Pb ages of 1774 +/- 26 Ma and 1721 +/- 25 Ma. These may be coeval with the Alto Terere metamorphic rocks of the northeastern corner, intruded in their turn by the Baia das Garcas granitic rocks, one of them yielding a zircon U-Pb age of 1754 +/- 49 Ma. The original magmatic protoliths of these rocks involved some crustal component, as indicated by the Sm-Nd TDm model ages, between 1.9 and 2.5 Ga. Regional Sr isotopic homogenization, associated with tectonic deformation and medium-grade metamorphism occurred at approximately 1670 Ma, as suggested by Rb-Sr whole rock reference isochrons. Finally, at 1300 Ma ago, the Ar work indicates that the Rio Apa Craton was affected by widespread regional heating, when the temperature probably exceeded 350 degrees C. Geographic distribution, age and isotopic signature of the fithotectonic units suggest the existence of a major suture separating two different tectonic domains, juxtaposed at about 1670 Ma. From that time on, the unified Rio Apa continental block behaved as one coherent and stable tectonic unit. It correlates well with the SW corner of the Amazonian Craton, where the medium-grade rocks of the Juruena-Rio Negro tectonic province, with ages between 1600 and 1780 Ma, were reworked at about 1300 Ma. Looking at the largest scale, the Rio Apa Craton is probably attached to the larger Amazonian Craton, and the actual configuration of southwestern South America is possibly due to a complex arrangement of allochthonous blocks such as the Arequipa, Antofalla and Pampia, with different sizes, that may have originated as disrupted parts of either Laurentia or Amazonia, and were trapped during later collisions of these continental masses.

The number of open paths in an oriented rho-percolation model

We study the asymptotic properties of the number of open paths of length n in an oriented rho-percolation model. We show that this number is e(n alpha(rho)(1+o(1))) as n ->infinity. The exponent alpha is deterministic, it can be expressed in terms of the free energy of a polymer model, and it can be explicitly computed in some range of the parameters. Moreover, in a restricted range of the parameters, we even show that the number of such paths is n(-1/2)We (n alpha(rho))(1+o(1)) for some nondegenerate random variable W. We build on connections with the model of directed polymers in random environment, and we use techniques and results developed in this context.

Students Working in Carpentry Shop at the New York Trade School

This black and white photograph shows students at work benches in part of the carpentry workshop at the New York Trade School. Beyond the benches two students can be seen working on framing in the rear of the classroom.

Democratic Deficit in the EU : Towards Parliamentary Democracy?!

Nowadays, the western societies are based on parliamentary democracy. Therefore, weak legislative power of the European Parliament is alleged for the democratic deficit in the EU. How it can be possible that the parliamentary democracy which is practiced on the national level can be achieved beyond the nation-states without diminishing the democracy at the nation-states? If not, how legitimacy can be obtained so that the continued existence and expansion of the EU should be justified? Since expectations for democratization of the EU are still unmet, finding answers to the actual questions is a great appeal. The thesis will explore the fundamental debates and arguments contributing to the democracy in the EU through the parliaments. I will try to reflect to the different ways of thinking and the prospects of establishing parliamentary democracy beyond the nation states.

The Evolution of a Responsibility to Protect in Africa : The African Unions Emerging Peace and Security Regime

The thesis focuses on, and tries to evaluate, the role that the African Union (AU) plays in protecting the peace and security on the African continent. The thesis takes an interdisciplinary approach to the topic by both utilizing international relations and international law theories. The two disciplines are combined in an attempt to understand the evolution of the AU’s commitment to the pragmatist doctrine: responsibility to protect (R2P). The AU charter is considered to be the first international law document to cover R2P as it allows the AU to interfere in the internal affairs of its member states. The R2P doctrine was evolved around the notion of a need to arrive at a consensus in regard to the right to intervene in the face of humanitarian emergencies. A part of the post-Cold War shift in UN behaviour has been to support local solutions to local problems. Hereby the UN acts in collaboration with regional organizations, such as the AU, to achieve the shared aspirations to maintain international peace and security without getting directly involved on the ground. The R2P takes a more holistic and long-term approach to interventions by including an awareness of the need to address the root causes of the crisis in order to prevent future resurrections of conflicts. The doctrine also acknowledges the responsibility of the international community and the intervening parties to actively participate in the rebuilding of the post-conflict state. This requires sustained and well planned support to ensure the development of a stable society.While the AU is committed to implementing R2P, many of the AU’s members are struggling, both ideologically and practically, to uphold the foundations on which legitimate intervention rests, such as the protection of human rights and good governance. The fact that many members are also among the poorest countries in the world adds to the challenges facing the AU. A lack of human and material resources leads to a situation where few countries are willing, or able, to support a long-term commitment to humanitarian interventions. Bad planning and unclear mandates also limit the effectiveness of the interventions. This leaves the AU strongly dependent on regional powerbrokers such as Nigeria and South Africa, which in itself creates new problems in regard to the motivations behind interventions. The current AU charter does not provide sufficient checks and balances to ensure that national interests are not furthered through humanitarian interventions. The lack of resources within the AU also generates worries over what pressure foreign nations and other international actors apply through donor funding. It is impossible for the principle of “local solutions for local problems? to gain ground while this donor conditionality exists.The future of the AU peace and security regime is not established since it still is a work in progress. The direction that these developments will take depends on a wide verity of factors, many of which are beyond the immediate control of the AU.

Contemporary Approaches to Translation in the Classroom : A study of students' Attitudes and Strategies

The purpose of this study is to explore the strategies and attitudes of students towards translation in the context of language learning. The informants come from two different classes at an Upper Secondary vocational program. The study was born from the backdrop of discussions among some English teachers representing different theories on translation and language learning, meeting students endeavoring in language learning beyond the confinement of the classroom and personal experiences of translation in language learning. The curriculum and course plan for English at the vocational program emphasize two things of particular interest to our study; integration of the program outcomes and vocational language into the English course - so called meshed learning – and student awareness of their own learning processes. A background is presented of different contrasting methods in translation and language learning that is relevant to our discussion. However, focus is given to contemporary research on reforms within the Comparative Theory, as expressed in Translation in Language and Teaching (TILT), Contrastive Analysis and “The Third Space”. The results of the students’ reflections are presented as attempts to translate two different texts; one lyric and one technical vocational text. The results show a pragmatic attitude among the students toward tools like dictionaries or Google Translate, but also a critical awareness about their use and limits. They appear to prefer the use of first language to the target language when discussing the correct translation as they sought accuracy over meaning. Translation for them was a natural and problem-solving event worth a rightful place in language teaching.

Coherence dynamics of two-mode condensates in asymmetric potentials

Detection of weak forces with an accuracy beyond the standard quantum limit holds promise both for fundamental research and for technological applications. Schemes involving ultracold atoms for such measurements are now considered to be prime candidates for increased sensitivity. In this paper we use a combination of analytical and numerical techniques to investigate the possible subshot-noise estimation of applied force fields through detection of coherence dynamics of Bose-condensed atoms in asymmetric double-well traps. Following a semiclassical description of the system dynamics and fringe visibility, we present numerical simulations of the full quantum dynamics that demonstrate the dynamical production of phase squeezing beyond the standard quantum limit. Nonlinear interactions are found to limit the achievable amount to a finite value determined by the external weak force.

Entry, re-location and growth in the Swedish wholesale trade industry

Wholesale trade has an intermediate position between manufacturing and retail in the distributional channel. In modern economies, consumers buy few, if any, products directly from manufacture or producer. Instead, it is a wholesaler, who is in direct contact with producers, buying goods in larger quantities and selling them in smaller quantities to retailers. Traditionally, the main function of a wholesaler has been to push goods along the distributional channel from producer to retailer, or other nonend user. However, the function of wholesalers usually goes beyond the process of the physical distribution of goods. Wholesalers also arrange storage, perform market analyses, promote trade or provide technical support to consumers (Riemers 1998). The existence of wholesalers (and other intermediaries) in the distributional channel is based on the effective and efficient performance of distribution services, that are needed by producers and other members of the supply chain. Producers usually do not enjoy the economies of scale that they have in production, when it comes to providing distributional services (Rosenbloom 2007) and this creates a space for wholesalers or other intermediaries. Even though recent developments in the distributional channel indicate that traditional wholesaling activities now also compete with other supply chain organizations, wholesaling still remains an important activity in many economies (Quinn and Sparks, 2007). In 2010, the Swedish wholesale trade sector consisted of approximately 46.000 firms and generated an annual turnover of 1 300 billion SEK (Företagsstatistiken, Statistics Sweden). In terms of turnover, wholesaling accounts for 20% of the gross domestic product and is thereby the third largest industry. This is behind manufacturing and a composite group of firms in other sectors of the service industry but ahead of retailing. This indicates that the wholesale trade sector is an important part of the Swedish economy. The position of wholesaling is further reinforced when measuring productivity growth. Measured in terms of value added per employee, wholesaling experienced the largest productivity growth of all industries in the Swedish economy during the years 2000 through 2010. The fact that wholesale trade is one of the important parts of a modern economy, and the positive development of the Swedish wholesale trade sector in recent decades, leads to several questions related to industry dynamics. The three topics that will be examined in this thesis are firm entry, firm relocation and firm growth. The main question to be answered by this thesis is what factors influence new firm formation, firm relocation and firm growth in the Swedish wholesale trade sector?

Gravitational self-localization for spherical masses

In this work, I consider the center-of-mass wave function for a homogenous sphere under the influence of the self-interaction due to Newtonian gravity. I solve for the ground state numerically and calculate the average radius as a measure of its size. For small masses, M≲10−17 kg, the radial size is independent of density, and the ground state extends beyond the extent of the sphere. For masses larger than this, the ground state is contained within the sphere and to a good approximation given by the solution for an effective radial harmonic-oscillator potential. This work thus determines the limits of applicability of the point-mass Newton Schrödinger equations for spherical masses. In addition, I calculate the fringe visibility for matter-wave interferometry and find that in the low-mass case, interferometry can in principle be performed, whereas for the latter case, it becomes impossible. Based on this, I discuss this transition as a possible boundary for the quantum-classical crossover, independent of the usually evoked environmental decoherence. The two regimes meet at sphere sizes R≈10−7 m, and the density of the material causes only minor variations in this value.