The Two-Point Function and the Effective Magnetic Field in Diluted Ising Models on the Cayley Tree

Some results on the two-point function and on the analytic structure of the momenta of the effective fugacity at the origin for a class of diluted ferromagnetic Ising models on the Cayley tree are presented.Comment: 22 page

Aspects of Two-Level Systems under External Time Dependent Fields

The dynamics of two-level systems in time-dependent backgrounds is under consideration. We present some new exact solutions in special backgrounds decaying in time. On the other hand, following ideas of Feynman, Vernon and Hellwarth, we discuss in detail the possibility to reduce the quantum dynamics to a classical Hamiltonian system. This, in particular, opens the possibility to directly apply powerful methods of classical mechanics (e.g. KAM methods) to study the quantum system. Following such an approach, we draw conclusions of relevance for ``quantum chaos'' when the external background is periodic or quasi-periodic in time.Comment: To appear in J. Phys. A. Mathematical and Genera

Converging Perturbative Solutions of the Schroedinger Equation for a Two-Level System with a Hamiltonian Depending Periodically on Time

We study the Schroedinger equation of a class of two-level systems under the action of a periodic time-dependent external field in the situation where the energy difference 2epsilon between the free energy levels is sufficiently small with respect to the strength of the external interaction. Under suitable conditions we show that this equation has a solution in terms of converging power series expansions in epsilon. In contrast to other expansion methods, like in the Dyson expansion, the method we present is not plagued by the presence of ``secular terms''. Due to this feature we were able to prove absolute and uniform convergence of the Fourier series involved in the computation of the wave functions and to prove absolute convergence of the epsilon-expansions leading to the ``secular frequency'' and to the coefficients of the Fourier expansion of the wave function

Numerical investigation of an inertization system for a radiative coil coating oven

Funding Information: This research was funded by the European Community's Framework Programme for Research and Innovation Horizon 2020 under grant agreement no. 768692 (ECCO). This work was also supported by Fundação para a Ciência e a Tecnologia, Portugal, through IDMEC, under LAETA, project UIDB/50022/2020. Funding Information: This research was funded by the European Community’s Framework Programme for Research and Innovation Horizon 2020 under grant agreement no. 768692 (ECCO) . This work was also supported by Fundação para a Ciência e a Tecnologia, Portugal , through IDMEC, under LAETA, project UIDB/50022/2020. Publisher Copyright: © 2023 The Author(s)In this work the inertization of a radiative curing oven for coil coating is numerically investigated. Inertization chambers (IC) — comprised by a confined impinging slot jet and an exhaust slot — are applied at the curing oven openings to prevent external air from entering and toxic solvents from exiting the oven, avoiding simultaneously the contamination of the external surroundings and the development of explosive conditions within the oven. The influence of the main IC operating parameters — extracted-to-injected mass flow rate ratio (Ψ), coil plate-to-jet velocity ratio, injection Reynolds number, and oven pressure — on the safety of the sealing process is investigated considering the validated k-kl-ω transition RANS model. To guarantee safety conditions regarding the IC placed at the metal strip entrance, the corresponding range for Ψ was found to be between 0.8 and 1.6 considering oven pressures ranging from −20 to 20 Pa. For the IC placed at the metal strip exit and considering high coil velocities, safety conditions can only be observed with negative oven pressures. Overall, this procedure found a Ψ range between 0.8 and 1.2 that complies with the restrictive safety criteria for a realistic oven operation with typical coil velocities and oven pressures ranging from −20 to 10 Pa.publishersversionpublishe

Universidade-Indústria: transferência de tecnologia em engenharia mecânica

A inovação nas pequenas e médias empresas industriais do ramo da Engenharia Mecânica é muitas vezes inexistenteou incipiente, podendo ser facilmente incrementada através de um estreito relacionamento e cooperação com asUniversidades e/ou os seus Institutos de Interface. Neste contexto, a Universidade do Porto, através do Departamentode Engenharia Mecânica e Gestão Industrial da Faculdade de Engenharia, fundou em 1986 o INEGI - Instituto deEngenharia Mecânica e Gestão Industrial, com a missão de reforçar a cooperação entre esta Universidade e o meioempresarial. O INEGI participa activamente, há 21 anos, no desenvolvimento da indústria nacional contribuindo comconhecimento e competências distintas na área da Engenharia Mecânica e Gestão Industrial, assumindo a missão de:Contribuir para o aumento da competitividade da indústria nacional através da investigação e desenvolvimento,demonstração, transferência de tecnologia e formação nas áreas de concepção e projecto, materiais, produção,energia, manutenção, gestão industrial e ambiente. Desde a sua criação, o INEGI tem tido um crescimentosustentado, tendo desenvolvido mais de 1300 projectos para organizações públicas e privadas, estando nestemomento numa fase de internacionalização, através do estabelecimento de protocolos e projectos conjuntos cominstituições internacionais.Esta comunicação pretende demonstrar as vantagens que as empresas podem obter, através de uma ligação ásUniversidades e Institutos de Interface, no desenvolvimento de materiais, produtos e processos tecnológicos,permitindo assim aumentar a sua competitividade. As áreas de intervenção dos projectos inovadores aqui focadosabrangem uma grande variedade de temas multidisciplinares, desde as energias renováveis, desenvolvimento deprocessos tecnológicos e sistemas mecânicos, materiais compósitos, prototipagem rápida e tecnologias avançadas deprodução e gestão industrial

Primary pulmonary melanoma: the unexpected tumour

A 62-year-old woman was referred to our pulmonology team with exertional dyspnoea and chest tightness of 2 months duration. Her medical history included cervical cancer and thyroid nodules. Imaging studies showed collapse of left upper lobe. Fiberoptic bronchoscopy unveiled an endoluminal lesion and bronchial biopsy displayed features of melanoma. She denied a history of melanoma or excision of lesions of skin, mucous membranes or the eye. A thorough evaluation including combined positron emission tomography with CT scan excluded other possible sites of primary melanoma, but there was a metastasis in a thoracic vertebra. Palliative radiotherapy of the spine was performed. Chemotherapy initiation with dacarbazine was postponed by the appearance of a malignant pleural effusion, confirmed by pleural fluid cytology. After four cycles chemotherapy was discontinued due to disease progression. The patient is still alive with a follow-up of 12 months, currently on best supportive care

Coordinate representation of particle dynamics in AdS and in generic static spacetimes

We discuss the quantum dynamics of a particle in static curved spacetimes in a coordinate representation. The scheme is based on the analysis of the squared energy operator E^2, which is quadratic in momenta and contains a scalar curvature term. Our main emphasis is on AdS spaces, where this term is fixed by the isometry group. As a byproduct the isometry generators are constructed and the energy spectrum is reproduced. In the massless case the conformal symmetry is realized as well. We show the equivalence between this quantization and the covariant quantization, based on the Klein-Gordon type equation in AdS. We further demonstrate that the two quantization methods in an arbitrary (N+1)-dimensional static spacetime are equivalent to each other if the scalar curvature terms both in the operator E^2 and in the Klein-Gordon type equation have the same coefficient equal to (N-1)/(4N).Comment: 14 pages, no figures, typos correcte

Anatomia endobrônquica: estudo prospectivo das variações anatómicas da árvore traqueobrônquica

ResumoO conhecimento detalhado do normal padrão de ramificações da árvore traqueobrônquica é um requisito essencial para qualquer pneumologista. Os sistemas de classificação funcional que guiam a prática clínica corrente têm um carácter eminentemente estático e raramente contemplam referências aos desvios possíveis dentro do espectro normal.Por forma a caracterizar as variações anatómicas da árvore traqueobrônquica, os autores desenvolveram um estudo prospectivo que decorreu entre Fevereiro e Julho de 2009, onde se incluíram todos os doentes referenciados para realização de broncofibroscopias diagnósticas e/ou terapêuticas.Um total de 181 indivíduos foram incluídos no estudo tendo-se observado variantes anatómicas em 79 (43% do total). Globalmente observamos 20 diferentes variantes anatómicas. Estas variantes foram mais frequentemente observadas no lobo superior direito (16,6%). O lobo médio e a língula não foram sede de variantes anatómicas. A variante mais frequentemente observada foi o padrão bifurcado do lobo superior direito (13,8%).O presente estudo revelou uma elevada frequência de formas alternativas ao clássico padrão de ramificação traqueobrônquica. O conhecimento da tipologia, morfologia e frequência de expressão dessas variantes revela-se de extrema importância para o broncologista no estabelecimento das fronteiras da anatomia normal e na planificação de técnicas endoscópicas ou de procedimentos cirúrgicos.AbstractA comprehensive knowledge of the normal pattern of endobronchial branching is essential to any pulmonologist. The classification systems available are predominantly static descriptions and only seldom do they refer to possible variations within the normal spectrum.To evaluate all possible anatomical variants of the tracheobronchial tree we conducted a prospective study in our endoscopy unit between February, 1st and July, 10th (2009).A total of 181 individuals were included in the study. Anatomical variants were found to be present in 79 individuals (43% of total). Overall we found 20 different anatomical variants. Variations were more frequently found within the right upper lobe (16.6% of individuals). Middle lobe and lingula presented no variations. The variant most frequently found was the presence of a bifurcate pattern of the right upper bronchus (13.8%).The present study revealed a relatively high frequency of anatomical alternatives to the normal endobronchial branching pattern. Recognition of these variants and the frequency of their expression are fundamental for the bronchologist in establishing the limits of normal anatomy and preparing endobronchial techniques or surgical procedures