A new convolution operator for the linear canonical transform with applications

The linear canonical transform plays an important role in engineering and many applied fields, as it is the case of optics and signal processing. In this paper, a new convolution for the linear canonical transform is proposed and a corresponding product theorem is deduced. It is also proved a generalized Young's inequality for the introduced convolution operator. Moreover, necessary and sufficient conditions are obtained for the solvability of a class of convolution type integral equations associated with the linear canonical transform. Finally, the obtained results are implemented in multiplicative filters design, through the product in both the linear canonical transform domain and the time domain, where specific computations and comparisons are exposed.Fundação para a Ciência e Tecnologiapublishe

New sampling theorem and multiplicative filtering in the FRFT domain

Having in consideration a fractional convolution associated with the fractional Fourier transform (FRFT), we propose a novel reconstruction formula for bandlimited signals in the FRFT domain without using the classical Shannon theorem. This may be considered the main contribution of this work, and numerical experiments are implemented to demonstrate the effectiveness of the proposed sampling theorem. As a second goal, we also look for the designing of multiplicative filters. Indeed, we also convert the multiplicative filtering in FRFT domain to the time domain, which can be realized by Fast Fourier transform. Two concrete examples are included where the use of the present results is illustrated.publishe

Disseminated Well-Differentiated Gastro-Entero-Pancreatic Tumors Are Associated with Metabolic Syndrome

The association of well-differentiated gastro-entero-pancreatic neuroendocrine tumors (WD GEP-NETs) with metabolic syndrome (MetS), abdominal obesity, and fasting glucose abnormalities was recently described. The aim of this study was to evaluate whether the presence of MetS or any MetS individual component was also influenced by GEP-NET characteristics at diagnosis. A cohort of patients with WD GEP-NETs (n = 134), classified according to primary tumor location (gastrointestinal or pancreatic), pathological grading (G1 (Ki67 ≤ 2%) and G2 (>3 ≤ 20%) (WHO 2010), disease extension (localized, loco-regional, and metastatic), and presence of hormonal secretion syndrome (functioning/non-functioning), was evaluated for the presence of MetS criteria. After adjustment for age and gender, the odds of having MetS was significantly higher for patients with WD GEP-NET grade G1 (OR 4.35 95%CI 1.30-14.53) and disseminated disease (OR 4.52 95%CI 1.44-14.15). GEP-NET primary tumor location or secretory syndrome did not influence the risk for MetS. None of the tumor characteristics evaluated were associated with body mass index, fasting plasma glucose category, or any of the individual MetS components. Patients with GEP-NET and MetS depicted a higher risk of presenting a lower tumor grade and disseminated disease. The positive association between MetS and GEP-NET characteristics further highlights the potential link between the two conditions.info:eu-repo/semantics/publishedVersio

Pre-heating boiler feedwater for expanded cork agglomerate production using a parabolic trough system

ABSTRACT: The production of expanded cork agglomerate involves significant heat demand, requiring superheated steam at temperatures ranging from 300°C to 370°C. The energy required to this process can be suitably provided by concentrating solar thermal collectors. This work considers the thermal energy needs of a real plant, presenting the technical and economical analysis performed for a solar heat for industrial process system using parabolic trough collectors to preheat the feedwater used by the boiler providing steam to the expanded cork agglomerate production process.info:eu-repo/semantics/publishedVersio

Development and assessment to environmentally friendly natural fiber composites

Two different types of natural fibers (jute and sisal) were studied and characterized, using optical microscopy, pycnometry density, single filament and linear density tests. Jute fibers were processed into composite parts from woven fabrics raw-material and sisal fibers were also processed into final composite componentes but in the form of chopped mat. Those fibers were used to reinforce polyester and epoxy matrices and therefore produce composite plates by resin infusion molding. Finally, the final obtained composite plates were submitted to mechanical testing, in order to assess their relevant mechanical properties.Fundação para a Ciência e a Tecnologia (FCT

Development and assessment of an over-expanded engine to be used as an efficiency-oriented range extender for electric vehicles

A range extender (RE) is a device used in electric vehicles (EVs) to generate electricity on-board, enabling them to significantly reduce the number of required batteries and/or extend the vehicle driving range to allow occasional long trips. In the present work, an efficiency-oriented RE based on a small motorcycle engine modified to the efficient over-expanded cycle, was analyzed, tested and simulated in a driving cycle. The RE was developed to have two points of operation, ECO: 3000 rpm, very high efficiency with only 15 kW; and BOOST: 7000 rpm with 35 kW. While the ECO strategy was a straightforward development for the over-expansion concept (less trapped air and a much higher compression ratio) the BOOST strategy was more complicated to implement and involved the need for throttle operation. Initially the concepts were evaluated in an in-house model and AVL Boost® (AVL List Gmbh, Graz, Austria), and proved feasible. Then, a BMW K75 engine was altered and tested on a brake dynamometer. The running engine proved the initial concept, by improving the efficiency for the ECO condition in almost 40% in relation to the stock engine and getting well over the required BOOST power, getting to 35 kW, while keeping an efficiency similar to the stock engine at the wide open throttle (WOT). In order to protect the engine during BOOST, the mixture was enriched, while at ECO the mixture was leaned to further improve efficiency. The fixed operation configuration allows the reduction, not only of complexity and cost of the RE, but also the set point optimization for the engine and generator. When integrated as a RE into a typical European light duty vehicle, it provided a breakthrough consumption reduction relatively to existing plug-in hybrid electric vehicles (PHEVs) in the market in the charge sustaining mode. The very high efficiency of the power generation seems to compensate for the loss of efficiency due to the excess electricity production, which must be stored in the battery. The results indicate that indeed it is possible to have an efficient solution, in-line with the electric mobility sustainability paradigm, which can solve most of the shortcomings of current EVs, notably those associated with batteries (range, cost and charging time) in a sustainable way.This Research was funded by MIT-Portugal EDAM, FCT, ERDF through Programa Operacional Fatores de Competitividade-COMPETE and National funds through PIDDAC, Project references MIT-Pt/EDAM-SMS/0030/2008 (MOBI-MPP-Assessment and Development of Integrated Systems for Electric Vehicles of the), UID/EMS/04077/2019 (MEtRICs -Mechanical Engineering and Resource Sustainability Centre Strategig Project) and grant numbers SFRH/BPD/89553/2012 (F.P. Brito) and SFRH/BSAB/142994/2018 (J Martins). AVL LIST GmbH provided free of charge an AVL Boost license through the University Partnership Program

Sludge volume index and suspended solids estimation of mature aerobic granular sludge by quantitative image analysis and chemometric tools

Aerobic granular sludge (AGS) is considered a promising technology for wastewater treatment. Furthermore, it is recognized that the stability of the process is related to the balanced growth of the suspended (floccular) and granular fractions. Therefore, the development of adequate techniques to monitor this balance is of interest. In this work the sludge volume index (SVI), volatile suspended solids (VSS) and total suspended solids (TSS) of mature AGS were successfully predicted with multilinear regression (MLR) models using data obtained from quantitative image analysis (QIA) of both fractions (suspended and granular). Relevant predictions were obtained for the SVI (R2 of 0.975), granules TSS (R2 of 0.985), flocs TSS (R2 of 0.971), granules VSS (R2 of 0.984) and flocs VSS (R2 of 0.986). The estimation of the granular fraction ratio from the predicted TSS and VSS was also successful (R2 of 0.985). The predictions help to avoid instability episodes of the AGS system, such as changes in biomass morphology, structure and settling properties.The authors thank the Portuguese Foundation for Science and Technology (FCT) under the scope of the strategic funding of UID/BIO/04469 unit, BioTecNorte operation (NORTE-01-0145-FEDER-000004) funded by the European Regional Development Fund under the scope of Norte2020 – Programa Operacional Regional do Norte and the project AGeNT – PTDC/BTA-BTA/31264/2017 (POCI-01-0145-FEDER031264). We would also like to thank the scientific collaboration under the FCT project UID/Multi/50016/2019. Cristiano Leal is recipient of a fellowship supported by a doctoral advanced training (call NORTE-692015-15) funded by the European Social Fund under the scope of Norte2020 – Programa Operacional Regional do Norte. A. Val del Rio is supported by Xunta de Galicia (ED418B 2017/075) and program Iacobus (2017/2018).info:eu-repo/semantics/publishedVersio

Teste de nomeação de categorias específicas: Estudo de adaptação portuguesa

O presente estudo visa o desenvolvimento de uma versão adaptada para a população portuguesa do Teste de Nomes de Categorias Específicas (McKenna, 1997). Trata-se de um instrumento de rastreio e avaliação neuropsicológica que permite identificar um défice caracterizado por uma dificuldade em nomear objectos das quatro categorias semânticas seguintes: Animais, Frutos e Legumes, Objectos Práxicos e Objectos Não práxicos. O original inglês apresenta-se sob duas formas:uma produtiva – a nomeação de imagens, e outra receptiva – o reconhecimento de imagens, podendo este ser feito a partir da palavra falada ou da palavra escrita.Foi desenvolvida em português a versão de nomeação, que foi aplicada a 56 indivíduos saudáveis do ponto de vista neurológico (grupo de controlo total) e a um grupo de 24 pacientes neurológicos comlesão cerebral unilateral (grupo clínico). O grupo clínico foi emparelhado com um subgrupo de controlo constituído por indivíduos com características semelhante sem termos de idade, escolaridade e sexo. Os resultados obtidos no grupo de controlo total mostram um interacção entre categoria e sexo, e um efeito principal de categoria. Verificou-se também que o grupo clínico obteve, em todas as categorias, resultados significativamente mais baixos do que o subgrupo de controlo emparelhado, o que neste estudo exploratório indicia a validade do instrumento

Novel and revisited approaches in nanoparticle systems for buccal drug delivery

The buccal route is considered patient friendly due to its non-invasive nature and ease of administration. Such delivery route has been used as an alternative for the delivery of drugs that undergo first-pass metabolism or are susceptible to pH and enzymatic degradation, such as occurs in the gastrointestinal tract. However, the drug concentration absorbed in the buccal mucosa is often low to obtain an acceptable therapeutic effect, mainly due to the saliva turnover, tongue and masticatory movements, phonation, enzymatic degradation and lack of epithelium permeation. Therefore, the encapsulation of drugs into nanoparticles is an important strategy to avoid such problems and improve their buccal delivery. Different materials from lipids to natural or synthetic polymers and others have been used to protect and deliver drugs in a sustained, controlled or targeted manner, and enhance their uptake through the buccal mucosa improving their bioavailability and therapeutic outcome. Overall, the main aim of this review is to perform an overview about the nanotechnological approaches developed so far to improve the buccal delivery of drugs. Herein, several types of nanoparticles and delivery strategies are addressed, and a special focus on pipeline products is also given.info:eu-repo/semantics/acceptedVersio