Módulos de pré-concentração miniaturizados mediante o uso da tecnologia LTCC e zeólitas.

A conjugação do binômio miniaturizaçãointegração tem permitido estabelecer a base conceitual para o desenvolvimento de uma nova geração de dispositivos miniaturizados, capazes de integrar todas as etapas necessárias para a realização de uma análise química. As cerâmicas verdes apresentam-se muito mais versáteis que qualquer dos materiais com os quais já se trabalhou até o momento no campo da miniaturização, dado que permitem a construção de dispositivos tridimensionais, de uma maneira rápida e simples. O objetivo desse trabalho é avaliar a zeólita natural como material para a construção de filtros empregados na préconcentração de fosfatos presentes na água, mediante sua integração em um dispositivo reutilizável baseado em cerâmicas verdes

Inverting the Supersymmetric Standard Model Spectrum: from Physical to Lagrangian Ino Parameters

We examine the possibility of recovering the supersymmetric (and soft supersymmetry breaking) Lagrangian parameters as direct {\em analytical} expressions of appropriate physical masses, for the unconstrained (but CP and R-parity conserving) minimal supersymmetric standard model. We concentrate mainly on the algebraically non-trivial "inversion" for the ino parameters, and obtain, for given values of $\tan\beta$, simple analytical expressions for the $\mu$, $M_1$ and $M_2$ parameters in terms of three arbitrary input physical masses, namely either two chargino and one neutralino masses, or alternatively one chargino and two neutralino masses. We illustrate and discuss in detail the possible occurrence of ambiguities in this reconstruction. The dependence of the resulting ino Lagrangian parameters upon physical masses is illustrated, and some simple generic behaviour uncovered in this way. We finally briefly sketch generalizing such an inversion to the full set of MSSM Lagrangian parameters.Comment: Latex, 28 pages, 6 figures, 1 table, some typos corrected, one paragraph extended in section 4.2. Version to appear in Phys. Rev.

b-tau Unification and neutrino masses in SU(5) extensions of the MSSM with radiative electroweak symmetry breaking

We make a complete analysis of the Yukawa coupling unification in SU(5) extensions of the MSSM in the framework of the radiative symmetry breaking scenario. Both logarithmic and finite threshold corrections of sparticles have been included in the determination of the gauge and Yukawa couplings at M_Z. The effect of the heavy masses of each model in the renormalization group equations is also included. We find that in the minimal SU(5) model b-tau Yukawa unification can be achieved for too large a value of alpha_s. On the other hand the Peccei-Quinn version of the Missing Doublet model, with the effect of the right handed neutrino also included, exhibits b-tau unification in excellent agreement with all low energy experimental data. Unification of all Yukawa couplings is also discussed.Comment: 20 pages, LaTeX2e,uses psfig,5 figures,full postscript file available at http://artemis.cc.uoi.gr/~adedes/new97.ps.g

Retrospective analysis of therapeutic response obtained with enteral and parenteral iron in adults with iron deficiency anaemia

AbstractBackgroundFew studies compare the therapeutic efficacy of different iron deficiency anaemia treatments.AimEvaluate the therapeutic response of the most common iron preparations.Material and methodsRetrospective, observational-analytical study based on medical records from the Haematology Department, conducted from March to October 2014, including 121 adults with ferropenic anaemia and 3-month follow-up. Patients with comorbidities or pregnancy were excluded.Results85.8% were women (n=103) and 14% men (n=17), with a mean age of 42 (16–83) years. Seventy patients (58.3%) started with oral administration; the rest received intravenous iron. Efficacy was similar among all the iron preparations, with no significant differences (p>0.05). Iron sucrose was most effective in rapidly replenishing body iron stores.ConclusionsDespite comparable efficacy among treatments, ferrous fumarate had the lowest treatment failure and was the therapy of choice

New method for determining the quark-gluon vertex

We present a novel nonperturbative approach for calculating the form factors of the quark-gluon vertex in terms of an unknown three-point function, in the Landau gauge. The key ingredient of this method is the exact all-order relation connecting the conventional quark-gluon vertex with the corresponding vertex of the background field method, which is Abelian-like. When this latter relation is combined with the standard gauge technique, supplemented by a crucial set of transverse Ward identities, it allows the approximate determination of the nonperturbative behavior of all 12 form factors comprising the quark-gluon vertex, for arbitrary values of the momenta. The actual implementation of this procedure is carried out in the Landau gauge, in order to make contact with the results of lattice simulations performed in this particular gauge. The most demanding technical aspect involves the approximate calculation of the components of the aforementioned (fully dressed) three-point function, using lattice data as input for the gluon propagators appearing in its diagrammatic expansion. The numerical evaluation of the relevant form factors in three special kinematical configurations (soft-gluon and quark symmetric limit, zero quark momentum) is carried out in detail, finding qualitative agreement with the available lattice data. Most notably, a concrete mechanism is proposed for explaining the puzzling divergence of one of these form factors observed in lattice simulations

Self-similar static solutions admitting a two-space of constant curvature

A recent result by Haggag and Hajj-Boutros is reviewed within the framework of self-similar space-times, extending, in some sense, their results and presenting a family of metrics consisting of all the static spherically symmetric perfect fluid solutions admitting a homothety.Comment: 6 page

Patterns of gauge symmetry in the background field method

The correlation functions of Yang-Mills theories formulated in the background field method satisfy linear Slavnov-Taylor identities, which are naive generalizations of simple tree level relations, with no deformations originating from the ghost sector of the theory. In recent years, a stronger version of these identities has been found to hold at the level of the background gluon self-energy, whose transversality is enforced separately for each special block of diagrams contributing to the gluon Schwinger-Dyson equation. In the present work we demonstrate by means of explicit calculations that the same distinct realization of the Slavnov-Taylor identity persists in the case of the background three-gluon vertex. The analysis is carried out at the level of the exact Schwinger-Dyson equation for this vertex, with no truncations or simplifying assumptions. The demonstration entails the contraction of individual vertex diagrams by the relevant momentum, which activates Slavnov-Taylor identities of vertices and multi-particle kernels nested inside these graphs; the final result emerges by virtue of a multitude of extensive cancellations, without the need of performing explicit integrations. In addition, we point out that background Ward identities amount to replacing derivatives of propagators by zero-momentum background-gluon insertions, in exact analogy to standard properties of Abelian gauge theories. Finally, certain potential applications of these results are briefly discussed.Comment: 35 pages, 9 figure