Gauge fields in a string-cigar braneworld

In this work we investigate the properties of an Abelian gauge vector field in a thin and in a smoothed string-like braneworld, the so-called string-cigar model. This thick brane scenario satisfies the regularity conditions and it can be regarded as an interior and exterior string-like solution. The source undergoes a geometric Ricci flow which is connected to a variation of the bulk cosmological constant. The Ricci flow changes the width and amplitude of the massless mode at the brane core and recover the usual thin string-like behavior at large distances. By numerical means we obtain the Kaluza-Klein (KK) spectrum for both the thin brane and the string-cigar. It turns out that both models exhibit a mass gap between the massless and the massive modes and between the high and the low mass regimes. The KK modes are smooth near the brane and their amplitude are enhanced by the string-cigar core. The analogue Schr\"odinger potential is also tuned by the geometric flow.Comment: The discussion about the Kaluza-Klein spectrum of the gauge field was improved. Numerical analysis was adapted to the conventional notation on Kaluza-Klein number. Some graphics were modified for considering other notation. Results unchanged. References added. Corrected typos. 17 pages. 6 figures. To match version to appears in Physics Letters

Rheological Behaviour of PP Nanocomposites by Extrusion Process

The effect of organophilic clay (C15A) in PP compatibilized polymer (PP/PP-g-MA) through rheological experimental results is presented. This study focusses on the description of the rheological behaviour of the organophilic layers along the screws of a twin screw extruder by melting process, varying the screw profile as well as the processing conditions, namely screw speed, temperature and feed rate. Different levels of dispersion were found along the screws for all conditions and positions analyzed by rheology. The qualitative analysis of the images obtained by transmission electron microscopy, reinforced the results. Furthermore, the effects of the processing conditions on dispersion of C15A layers along the screw profile are analyzed using multiple linear regression techniques. The results show statistically significant differences of all rheology measures for all the processing conditions and positions along the extruder.info:eu-repo/semantics/publishedVersio

Performance of Sparse Binding Arrays for Or-Parallelism

One important problem in the design of novel logic programming systems is the support of several forms of implicit parallelism. A new binding model, the Sparse Binding Array (SBA), has been proposed for the efficient and simplified integration of Independent-And, Determinate-And and Or-parallelism. In this paper we report on the use of this model for pure Or-parallelism. The work discusses the major implementation issues in supporting this binding model for pure Or-parallelism. We show that an implementation based on this Binding model is more efficient then the original Aurora using tbe traditional Binding Array model [16]. Moreover, we explain how the notion of a variable level can be used to reduce overheads of the Orparallel system. Our results in supporting pure or-parallelism show that the approach is very promissing for combined paralell systems.</jats:p

Scrap production of extruded aluminum alloys by direct extrusion

The growing globalization of the different types of market requires that companies invest, in a recurrent way, to optimize and improve all the processes inherent to their activities. Aluminium extrusion is the main industrial process used to create profiles of a fixed cross-section. This process requires appropriate processing parameters to be used, in order to produce diverse profiles and high-quality products. The company’s ability to adapt and improve the productive process are differentiating factors against the competition. Thus, understand the main operations and dynamics of the companies is crucial. This work presents an empirical study concerning the extrusion process of a Portuguese company in the aluminium sector. By analysing a real data base provided by the company, the main objective is to model the aluminium extrusion process. Taking into account the variables that most influence the extrusion of different profiles, the aim is to minimize the production of scrap. First, by studying the literature in the subject, the variables that most contribute to scrap production were identified. Since the database provided by the company did not present all the variables described in literature, proxy variables were considered. Next, a multivariate linear regression model for explaining the amount of scrap taking as explanatory the identified variables was estimated. With this analysis, it was possible to identify levels of significance of the variables under study, and therefore understand how each of the variables contributes to the increase or decrease of the amount of scrap on the production of aluminium profiles. The results show that variables concerning with extrusion temperature, time, speed, pressure and die geometry are crucial to improve and control the scrap production. The obtained model will be improved, in future work, by including further variables of the extrusion process. Furthermore, factor analysis and GHML methodologies will also be considered for explaining the production of scrap and therefore improve the production process.info:eu-repo/semantics/publishedVersio

Neoadjuvant use of Imiquimod Before Surgery in Extramammary Paget’s Disease

A doença de Paget extramamária (DPEM) é uma neoplasia maligna cutânea, rara, observada principalmente em mulheres caucasianas pós-menopausa. A cirurgia é o tratamento mais comum. No entanto, no que diz respeito à DPEM vulvar, o seu tratamento cirúrgico passa frequentemente por cirurgia radical, que pode ser mutilante e levar à perda de feminilidade. Recentes avanços terapêuticos têm incluído abordagem médica e multimodal médico-cirúrgico, permitindo uma maior preservação da anatomia genital e subsequente diminuição da morbilidade. Neste sentido, imiquimod tem sido utilizado, off-label, como monoterapia ou terapêutica adjuvante na DPEM.Relatamos o caso de uma mulher com DPEM extenso na área anogenital submetida a resseção cirúrgica complementada com reconstrução plástica e precedida de tratamento médico com imiquimod. O imiquimod neoadjuvante permitiu uma citorredução significativa da área tumoral, minimizando a radicalidade cirúrgica, mantendo a função local e a morfologia.Extramammary Paget's disease (EMPD) is a distinct form of a rare malignant skin neoplasm, primarily seen in postmenopausal Caucasian women. Surgery is the most common treatment. However, concerning vulvar EMPD, radical surgery can be mutilating and leads to loss of femininity. Recent therapeutic development has included medical and medical-surgical approaches, allowing better preservation of genital anatomy with subsequent reduced morbidity. Accordingly, off-label use of imiquimod has been reported as a monotherapy or adjuvant therapy in EMPD.We report the case of a woman with extensive EMPD in the anogenital area, submitted to surgical resection complemented with plastic reconstruction and preceded by imiquimod medical treatment. Neoadjuvant imiquimod induced a significant cytoreduction of the tumor area, minimizing surgical radicality and maintaining local function and morpholog