Renormalization group in Statistical Mechanics and Mechanics: gauge symmetries and vanishing beta functions

Two very different problems that can be studied by renormalization group methods are discussed with the aim of showing the conceptual unity that renormalization group has introduced in some areas of theoretical Physics. The two problems are: the ground state theory of a one dimensional quantum Fermi liquid and the existence of quasi periodic motions in classical mechanical systems close to integrable ones. I summarize here the main ideas and show that the two treatments, although completely independent of each other, are strikingly similar.Comment: Plain TeX, 20 pages 7 figures (included in ps format

The Gravitational Polarization in General Relativity: Solution to Szekeres' Model of Quadrupole Polarization

A model for the static weak-field macroscopic medium is analyzed and the equation for the macroscopic gravitational potential is derived. This is a biharmonic equation which is a non-trivial generalization of the Poisson equation of Newtonian gravity. In case of the strong gravitational quadrupole polarization it essentially holds inside a macroscopic matter source. Outside the source the gravitational potential fades away exponentially. The equation is equivalent to a system of the Poisson equation and the nonhomogeneous modified Helmholtz equations. The general solution to this system is obtained by using Green's function method and it does not have a limit to Newtonian gravity. In case of the insignificant gravitational quadrupole polarization the equation for macroscopic gravitational potential becomes the Poisson equation with the matter density renormalized by the factor including the value of the quadrupole gravitational polarization of the source. The general solution to this equation obtained by using Green's function method has a limit to Newtonian gravity.Comment: 22 pages, no figures, to appear on Class. Quantum Gra

Not Alone: A Research On Successful Partnerships Between Private Companies and Citizens' Organizations in Europe

The final report analyses a research project carried out by the Active Citizenship Foundation (FONDACA) and the Active Citizenship Network (ACN) on the partnerships involving businesses and citizens' organisations in Europe. This project was conducted in eight European Union Countries (Austria, Germany, Hungary, Italy, Malta, Poland, Slovenia, United Kingdom).The report includes three pages of bibliographical references and an annex consisting of a questionnaire for interviews with Key persons evaluating CSR partnerships between companies and citizens' organisations

Frailty and elderly in urology: Is there an impact on post-operative complications?

INTRODUCTION: Frailty used as predictive tool is still not carried out in daily practice, although many studies confirm the great clinical importance of the frailty syndrome in surgical outcomes. There is no standardized method of measuring the physiological reserves of older surgical patients. The aim of this study was to analyze a cohort of older urological patients according to various frailty indices, in order to evaluate whether they are predictors of post-operative complications after urological procedures. MATERIAL AND METHODS: This is a prospective observational study on 78 consecutive older ( 6570 years) patients, subjected to major urological (both endoscopic and 'open surgical') procedures. Frailty was defined according to the Edmonton Frail Scale. Several risk models and biochemical parameters were evaluated. Post-operative outcomes were surgical and medical complications, mortality and rehospitalisation within 3 months. RESULTS: An overall prevalence of frailty of 21.8% was found. Patients with complications were frailer than those without complications (univariate analysis), considering both total patients (p = 0.002) and endoscopic (p = 0.04) and 'open surgical' patients (p = 0.013). However, in multivariate analysis, a significant correlation was not found between all frailty indices tested and the risk of major complications. Limitation of the study: the small sample size (lack of statistical power), although this is a prospective study focused on older urological patients. CONCLUSIONS: New urology-tailored pre-operative assessment tools may prove beneficial when calculating the risks/benefits of urological procedures, so that objective data can guide surgical decision- making and patient counselling. Further large clinical studies specifically focusing on elderly in urology will be needed

Monte Carlo strategy for SEM-EDS micro-nanoanalysis of geopolymer composites

The development, optimization and application of new geopolymer composite materials must necessarily go through a precise and accurate physico-chemical and mineralogical characterization down to the micro and nanoscale. In this regard, SEM-EDS X-ray microanalysis is widely and successfully employed by the scientific community and industry. However, the nano-to-micrometre sized architecture of many geopolymer composites introduces many difficulties and issues in SEM-EDS quantification, with potential large sources of error that should carefully be taken into account and investigated. In this work, a SEM-EDS Monte Carlo approach is proposed to study the complex physical phenomena at the basis of the quantification issues and errors, through the investigation of: (i) a not completely reacted sodium-poly(sialate-siloxo) geopolymer, and (ii) a geopolymer composite with a potassium-poly(sialate-siloxo) matrix and basalt-derived glass fibres reinforcement. The Monte Carlo simulation evinced a strong influence of the nano-microsized specimen architecture (e.g., basalt fibre size and shape, different elemental composition between fibre and matrix) on the measured X-ray intensity, with contributions also depending on the SEM electron beam energy. The proposed approach provided fundamental indications for selecting optimal operative conditions depending on the type of geopolymer sample, shape, size with the specific SEM-EDS setup and silicon drift EDS detector here used

Simulated infrared and Raman spectroscopy, complex dielectric function and refractive index dataset of monoclinic C2/m stoichiometric clinochlore Mg6Si4O10(OH)8 as obtained from Density Functional Theory

This article reports a simulated dataset of the vibrational (infrared and Raman) and optical properties (complex dielectric function and refractive index) of clinochlore, an important mineral belonging to the phyllosilicate family [1]. The data here reported were calculated from ab initio Density Functional Theory (DFT) simulations at B3LYP level, including a correction for the dispersive forces (B3LYP-D* approach) and all-electron Gaussian-type orbitals basis sets. This dataset was calculated between 0 cm–1 and 4000 cm–1 and comprises infrared, reflectance and Raman spectra, frequency-dependent complex dielectric function and complex refractive index of clinochlore. The data was validated against available experimental spectroscopic results reported in literature and can be of help in several application fields, for instance fundamental georesource exploration and exploitation, in applied mineralogy, geology, material science, and as a reference to assess the quality of other theoretical approaches

Exact equations of state for nematics

We propose a novel approach to the solution of nematic Liquid Crystal models based on the derivation of a system of nonlinear wave equations for order parameters such that the occurrence of uniaxial and biaxial phase transitions can be interpreted as the propagation of a two-dimensional shock wave in the space of thermodynamic parameters. We obtain the exact equations of state for an integrable model of biaxial nematic liquid crystals and show that the classical transition from isotropic to uniaxial phase in absence of external fields is the result of a van der Waals type phase transition, where the jump in the order parameters is a classical shock generated from a gradient catastrophe at a non-zero isotropic field. The study of the equations of state provides the first analytical description of the rich structure of nematics phase diagrams in presence of external fields

Complete integrability and equilibrium thermodynamics of biaxial nematic systems with discrete orientational degrees of freedom

We study a discrete version of a biaxial nematic liquid crystal model with external fields via an approach based on the solution of differential identities for the partition function. In the thermodynamic limit, we derive the free energy of the model and the associated closed set of equations of state involving four order parameters, proving the integrability and exact solvability of the model. The equations of state are specified via a suitable representation of the orientational order parameters, which imply two-order parameter reductions in the absence of external fields. A detailed exact analysis of the equations of state reveal a rich phase diagram where isotropic versus uniaxial versus biaxial phase transitions are explicitly described, including the existence of triple and tricritical points. Results on the discrete models are qualitatively consistent with their continuum analog. This observation suggests that, in more general settings, discrete models may be used to capture and describe phenomena that also occur in the continuum for which exact equations of state in closed form are not available.Comment: 27 pages, 5 figure

Utilização de fontes dietéticas não protéicas de energia pelo jundiá, Rhamdia quelen: crescimento, atividade de enzimas digestivas e utilização dos nutrientes

Dissertação (mestrado) - Universidade Federal de Santa Catarina, Centro de Ciências Agrárias. Programa de Pós-Graduação em AquiculturaA carne de frango produzida em sistemas alternativos ao industrial tem uma demanda crescente pelos consumidores. Entretanto, as linhagens caipiras existentes são de crescimento lento e baixa conversão alimentar, comparadas às linhagens industriais, o que onera a produção. Já o uso de frangos de linhagens industriais em sistemas "alternativos" tem como limitação a necessidade de uso de antibióticos e coccidiostáticos na ração. O presente experimento objetivou avaliar a eficácia de medicamentos homeopáticos no desempenho e saúde de frangos de corte criados com acesso a pasto. Dois grupos de 90 frangos da linhagem industrial Cobb foram aleatoriamente alocados, a partir dos 21 dias de vida, a três tratamentos: Controle (CN), Calcarea carbonica CH12 (CC) e Calcarea phosphorica CH12 (CP), num desenho de blocos completamente casualizados em duas etapas. Em cada etapa havia três blocos, totalizando seis repetições por tratamento, cada uma formada por um lote de 10 frangos, alojados numa baia de 4m2 com 6m2 de pasto. O experimento foi realizado no verão de 2008, no Setor de Avicultura do Centro de Ciências Agrárias da UFSC. As aves foram pesadas aos 21 dias e semanalmente até o abate aos 49 dias. Após o abate, também foram pesados carcaça, coração, fígado, moela e pés. Na segunda etapa, na semana que antecedeu a transferência dos animais do pinteiro para as baias, houve fortes chuvas, o que deve ter provocado estresse nos pintos, que aos 21 dias, pesaram 523g, enquanto na primeira etapa o peso nessa idade foi de 893g. Assim, houve diferença entre etapas no peso final (Etapa 1 = 3469,5 38,4g, Etapa 2 = 3348,1 40,0g; P0,40). Já o fígado e coração foram significativamente mais pesados na etapa 2 (P<0,01). O maior peso de fígado e coração na segunda etapa pode ser interpretado como um indicador de maior atividade metabólica desses órgãos, coincidente com o maior ganho de peso. Em ambas as etapas o peso do fígado foi menor (P<0,05) no tratamento com Calcarea carbonica. O menor peso de fígado observado nas aves tratadas com Calcarea carbonica, pode estar associado a uma redução à suscetibilidade ao estresse, no entanto são necessários novos estudos para confirmar este efeito. Conclui-se que a homeopatia utilizada não teve efeito no desempenho de frangos de corte de genética industrial criados em sistema de semi-confinamento. Esses resultados também sugerem a possibilidade da criação de frangos de genética industrial sem aditivos e antibióticos, e num sistema de semi-confinamento ou "alternativo", desde que se garantam condições profiláticas e instalações adequadas