929 research outputs found

    Finite size effects in the phase transition patterns of coupled scalar field systems

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    It is considered in this work the phase transition patterns for a coupled two-scalar field system model under the combined effects of finite sizes and temperature. The scalar fields are taken as propagating in a D=4 Euclidean space with the usual periodic compactification in the Euclidean time direction (with dimension given by the inverse of the temperature) and also under a compact dimension in the space direction, which is restricted to size L. In the latter case, a Dirichlet boundary condition is considered. Finite-size variation of the critical temperature for the cases of symmetry restoration and inverse symmetry breaking are studied. At fixed finite-temperature values, the variation of the inverse correlation lengths with the size L might display a behavior analogous to reentrant phase transitions. Possible applications of our results to physical systems of interest are also discussed.Comment: 19 pages, 8 figures. Many clarifications added. Version matching the published one in the Physical Review

    A fast method using a new hydrophilic–lipophilic balanced sorbent in combination with ultra-high performance liquid chromatography for quantification of significant bioactive metabolites in wines

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    This manuscript describes the development and validation of an ultra-fast, efficient, and high throughput analytical method based on ultra-high performance liquid chromatography (UHPLC) equipped with a photodiode array (PDA) detection system, for the simultaneous analysis of fifteen bioactive metabolites: gallic acid, protocatechuic acid, (−)-catechin, gentisic acid, (−)-epicatechin, syringic acid, p-coumaric acid, ferulic acid, m-coumaric acid, rutin, trans-resveratrol, myricetin, quercetin, cinnamic acid and kaempferol, in wines. A 50-mm column packed with 1.7-μm particles operating at elevated pressure (UHPLC strategy) was selected to attain ultra-fast analysis and highly efficient separations. In order to reduce the complexity of wine extract and improve the recovery efficiency, a reverse-phase solid-phase extraction (SPE) procedure using as sorbent a new macroporous copolymer made from a balanced ratio of two monomers, the lipophilic divinylbenzene and the hydrophilic N-vinylpyrrolidone (Oasis™ HLB), was performed prior to UHPLC–PDA analysis. The calibration curves of bioactive metabolites showed good linearity within the established range. Limits of detection (LOD) and quantification (LOQ) ranged from 0.006 μg mL−1 to 0.58 μg mL−1, and from 0.019 μg mL−1 to 1.94 μg mL−1, for gallic and gentisic acids, respectively. The average recoveries ± SD for the three levels of concentration tested (n = 9) in red and white wines were, respectively, 89 ± 3% and 90 ± 2%. The repeatability expressed as relative standard deviation (RSD) was below 10% for all the metabolites assayed. The validated method was then applied to red and white wines from different geographical origins (Azores, Canary and Madeira Islands). The most abundant component in the analysed red wines was (−)-epicatechin followed by (−)-catechin and rutin, whereas in white wines syringic and p-coumaric acids were found the major phenolic metabolites. The method was completely validated, providing a sensitive analysis for bioactive phenolic metabolites detection and showing satisfactory data for all the parameters tested. Moreover, was revealed as an ultra-fast approach allowing the separation of the fifteen bioactive metabolites investigated with high resolution power within 5 min

    Ação inibidora de óleos essenciais sobre o crescimento micelial de Botrytis cinerea.

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    Assim, o objetivo deste trabalho foi testar diferentes óleos essenciais no controle de B. cinerea

    Customer service orientation on adhesion contracts

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    Hiring a service is a moment of great importance once it builds the perception of the service value and quality. Some companies may deal with that, assuming a greater importance when elaborating their service contracts. Usually law professional people elaborate these documents, but this may include legal attributes, not considering the service to the customers, as well as the customers’ point of view. In times of increasing on customer focus, market and service orientation, a question can be posted: to what extent company contracts show service or customer orientation? This paper compares the service orientation degree for Cable TV contracts from five companies, based on a theoretical model developed to this purpose. From a conceptual model for servant contract, four dimensions were assessed: physical aspects, reasonableness, intelligibility and customer focus. After subject evaluation by eight judges, analyzing the validation index (CVI), it was found that the contracts show moderate orientation to serve. Furthermore, results show that the five surveyed company’s contracts showed a similar overall performance, i.e., none stood out over the other. The study presents important practical efficacy, because it can guide the Cable TV companies to adopt improvement strategies in elaboration of contracts, so that the contractual instruments be would reviewed of clauses that promote the sensation of better service to their customer. Thus, this article directs the manager to the aspect that deserves more attention, i.e, which dimensions require further refinement and direction to serv

    Body image perception in scholars of a school in the brazilian north region

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    Introduction: In the adolescence period, an individual experiences biopsychosocial changes and dissatisfaction with body image is quite prevalent at this stage. Objective: To investigate the prevalence of body image dissatisfaction and its association with demographic and psychosocial factors, sexual maturity, nutritional condition and lifestyle. Method: Cross-sectional study with a sample representing 831 eighth grade students from Porto Velho, Rondônia, Brazil, stratified into clusters. The data were obtained by questi onnaires - the Body Shape Questionnaire and Global School-based Student Health Survey - and anthropometry. The associations of interest were tested in a multivariate analysis with Cox regression adjusted for cross-sectional studies. Results: The prevalence of body image dissatisfaction was 22 per cent. The outcome was signifi cantly more prevalent among girls (PR: 4.69; CI: 95%: 3.09 – 7.12), young Caucasians (PR: 1.32; CI: 95%: 1.02 – 1.72), those who used tobacco (RP: 1.53; CI: 95%: 1.12 – 2.09), who were overweight or obese (PR: 2.77; CI: 95%: 2.18 – 3.51), and who reported feelings of sadness (PR: 1.35; CI: 95%: 1.05 – 1.73) and loneliness (PR: 1.66; CI: 95%: 1.30 – 2.11). The students with lower weight were more satisfied with their image. Conclusion: The results point to the need for parents, educators and health professionals to act jointly in developing actions that reinforce the positive qualities of youth, especially in girls. Encouraging physical activity and healthy habits can promote overall health, improving satisfaction with body image

    Geo-environmental mapping using physiographic analysis: constraints on the evaluation of land instability and groundwater pollution hazards in the Metropolitan District of Campinas, Brazil

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    Geo-environmental terrain assessments and territorial zoning are useful tools for the formulation and implementation of environmental management instruments (including policy-making, planning, and enforcement of statutory regulations). They usually involve a set of procedures and techniques for delimitation, characterisation and classification of terrain units. However, terrain assessments and zoning exercises are often costly and time-consuming, particularly when encompassing large areas, which in many cases prevent local agencies in developing countries from properly benefiting from such assessments. In the present paper, a low-cost technique based on the analysis of texture of satellite imagery was used for delimitation of terrain units. The delimited units were further analysed in two test areas situated in Southeast Brazil to provide estimates of land instability and the vulnerability of groundwater to pollution hazards. The implementation incorporated procedures for inferring the influences and potential implications of tectonic fractures and other discontinuities on ground behaviour and local groundwater flow. Terrain attributes such as degree of fracturing, bedrock lithology and weathered materials were explored as indicators of ground properties. The paper also discusses constraints on- and limitations of- the approaches taken

    The palace of the Marquises of Alegrete in Mouraria: the absent palace and the place memory

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    Built by Manuel Teles da Silva (1641-1709), 2nd count of Vilar Maior and 1st Marquis of Alegrete, and named after his title, this sumptuous palace built near the Ferdinand Wall, stood out as an important Noble House in the context of the civil architecture of Lisbon, in the early 18th century. After a long and troubled life, due to the modifications caused by successive social and urban adaptations it would become finally demolished in 1946. In this article we propose to study this building, based on several collections, mainly in the municipal archives, in two specific moments: its foundation and initial construction, and the years that corresponded to its degradation and demolition, as well as those who dwelt in addition to its relationship with the surrounding urban area.info:eu-repo/semantics/publishedVersio
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