Geometric phase accumulated in a driven quantum system coupled to an structured environment

We study the role of driving in a two-level system evolving under the presence of a structured environment. We find that adding a periodical modulation to the two-level system can greatly enhance the survival of the geometric phase for many time periods. We show that this effect is mainly important for a markovian regimen but can still be found when the environment exhibits non-markovian behavior as time revivals. This knowledge can aid the search for physical set-ups that best retain quantum properties under dissipative dynamics.Comment: To appear in Phys. Rev. A. arXiv admin note: text overlap with arXiv:1001.3564 by other author

An empirical formulation to describe the evolution of the high burnup structure

In the present work the behavior of fuel pellets for LWR power reactors in the high burnup range (average burnup higher than about 45 MWd/kgU) is analyzed. For extended irradiation periods, a considerable Pu concentration is reached in the pellet periphery (rim zone), that contributes to local burnup. Gradually, a new microstructure develops in that ring, characterized by small grains and large pores as compared with those of the original material. In this region Xe is absent from the solid lattice (although it continues to be dissolved in the rest of the pellet). The porous microstructure in the pellet edge causes local changes in the mechanical and thermal properties, thus affecting the overall fuel behaviour. It is generally accepted that the evolution of porosity in the high burnup structure (HBS) is determinant of the retention capacity of the fission gases rejected from the fuel matrix. This is the reason why, during the latest years a considerable effort has been devoted to characterizing the parameters that influence porosity. Although the mechanisms governing the microstructural transformation have not been completely elucidated yet, some empirical expressions can be given, and this is the intention of the present work, for representing the main physical parameters. Starting from several works published in the open literature, some mathematical expressions were developed to describe the behaviour and progress of porosity at local burnup values ranging from 60 to 2 300 MWd/kgU. The analysis includes the interactions of different orders between pores, the growth of the pore radius by capturing vacancies, the evolution of porosity, pore number density and overpressure within the closed pores, the inventory of fission gas dissolved in the matrix and retained in the pores. The model is mathematically expressed by a system of non-linear differential equations. In the present work, results of this calculation scheme are compared with experimental data available in the open literature and with simulations performed by other authors. The results of these separate tests are quite satisfactory so, the next step will be the incorporation of this model as a new subroutine of the DIONISIO code, to expand the application range of this general fuel behaviour simulation tool.Fil: Lemes, Martín. Comisión Nacional de Energía Atómica; ArgentinaFil: Soba, Alejandro. Comisión Nacional de Energía Atómica; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Denis, Alicia Catalina. Comisión Nacional de Energía Atómica; Argentin

Europe's ecological backbone: recognising the true value of our mountains

Europe's mountain areas have social, economic and environmental capital of significance for the entire continent. This importance has been recognised since the late 19th century through national legislation; since the 1970s through regional structures for cooperation; and since the 1990s through regional legal instruments for the Alps and Carpathians. The European Union (EU) first recognised the specific characteristics of mountain areas in 1975 through the designation of Less Favoured Areas (LFAs). During the last decade, EU cohesion policy and the Treaty of Lisbon have both focused specifically on mountain

The study of G.C.E (O/L) students who are not qualified for studying advanced level

The formal education is the crucial part of a Student’s educational process. In that way G.C.E O/L is also an important stage for further educational Development. According to the studies, most of the students who sit for G.C.E (O/L) examination are unable to qualify the exam to continue G.C.E (A/L). Although they possess enough qualification to study further, they break down in the mid journey in leering with no hopes and interest on education. There for this research gives opportunity to boost the Students of G.C.E O/L in upgrading towards A/L and promote their achievement through various ways. This study finds the reason why students are unable to get qualified to study A/L even though they spent 11 years in this educational liner period. In this context it is important to understand the role of students, teachers, and parents. It is very important to identify the background of the research area, and the factors influencing on student’s achievement. This research is done thought Survey method. Quantitative and qualitative methodologies are also used. Six Schools from the Batticaloa North division has been selected for sampling. Observation, questionnaire and in-depth interviews are mostly focused, date has been also collected thought written structured questionnaire from Z.D, principle, teachers, students. Secondary date is collected from relevant literature, official documents and administrative reports

Implementation of Food Insecurity Screening in Clinical Setting

This project used the Stetler model of research utilization framework to apply evidence-based findings to clinical settings screening adults with type II diabetes mellitus (T2DM) and low incomes for food insecurity. The project involved the review and critical appraisal of research studies and translation of research-based knowledge into a protocol for the Peach Tree Clinic with respect to the impact of food insecurity on diabetes outcomes in adults with T2DM and low incomes who were at risk of food insecurity. In addition, the proportion of screened at-risk patients who received nutritional counseling was calculated. The proportion of patients with T2DM screened for food insecurity increased from the baseline value of 0% to 82%, over the 3-month implementation period. Therefore, the project aim was surpassed. The quality improvement committee was presented with the project results for incorporation into the clinic’s policies and procedures for sustainability

Ex Ante Impact Assessment of Policies Affecting Land Use, Part B: Application of the Analytical Framework

The use of science-based tools for impact assessment has increasingly gained focus in addressing the complexity of interactions between environment, society, and economy. For integrated assessment of policies affecting land use, an analytical framework was developed. The aim of our work was to apply the analytical framework for specific scenario cases and in combination with quantitative and qualitative application methods. The analytical framework was tested for two cases involving the ex ante impact assessment of: (1) a European Common Agricultural Policy (CAP) financial reform scenario employing a modeling approach and combined with a comprehensive indicator analysis and valuation; and (2) a regional bioenergy policy scenario, employing a fully participatory approach. The results showed that European land use in general is less sensitive to changes in the Common Agricultural Policy, but in the context of regions there can be significant impacts on the functions of land use. In general, the implementation of the analytical framework for impact assessment proved to be doable with both methods, i.e., with the quantitative modeling and with the qualitative participatory approach. A key advantage of using the system of linked quantitative models is that it makes possible the simultaneous consideration of all relevant sectors of the economy without abstaining from a great level of detail for sectors of particular interest. Other advantages lie in the incontestable character of the results. Based on neutral, existing data with a fixed set of settings and regions, an absolute comparability and reproducibility throughout Europe can be maintained. Analyzing the pros and cons of both approaches showed that they could be used complementarily rather than be seen as competing alternatives

Petrogenesis of highly fractionated I-type peraluminous granites : La Pedriza pluton (Spanish Central System)

The La Pedriza pluton stands out as the most extensively fractionated granite (Rb < 629; Sr < 2 and Ba < 2 ppm) of the Spanish Central System Batholith. These granites show a strong enrichment in some rare metal contents (Nb = 44, Y = 136, Yb = 10.7, U = 17, Ta = 7, Sc = 15 ppm). The petrography and geochemistry (including Sr- Nd isotopes) reveal that the pluton is composed of at least four units. These are classified as I-type peraluminous leucogranites (A/CNK=1.03-1.17), P-poor (P2O5<0.2 wt%) and Na2O-rich (< 4.24 wt%) exhibiting differences in their HFSE and REE contents and ?Nd compositions. Moreover, the units of the La Pedriza granite display different trends of fractional crystallization. REE spectra of the two most fractionated units suggest the involvement of a fluorine-rich melt in the last stages favouring the crystallization of xenotime and niobotantalates. Intermediate meta-igneous granulite protoliths are proposed as source rocks. The most evolved units of the La Pedriza pluton show chemical features convergent to A-type granites; these are explained by extensive fraccional crystallization of a P-poor, I-type granite magma