Large area image sensing structures based on a-SiC : H: a dynamic characterization

In recent works large area hydrogenated amorphous silicon p-i-n structures with low conductivity doped layers were proposed as single element image sensors. The working principle of this type of sensor is based on the modulation, by the local illumination conditions, of the photocurrent generated by a light beam scanning the active area of the device. In order to evaluate the sensor capabilities is necessary to perform a response time characterization. This work focuses on the transient response of such sensor and on the influence of the carbon contents of the doped layers. In order to evaluate the response time a set of devices with different percentage of carbon incorporation in the doped layers is analyzed by measuring the scanner-induced photocurrent under different bias conditions

First and second fundamental solutions of the time-fractional telegraph equation of order 2α

In this work we obtain the first and second fundamental solutions of the multidimensional time-fractional equation of order $2\alpha$, $\alpha \in ]0,1]$, where the two time-fractional derivatives are in the Caputo sense. We obtain representations of the fundamental solutions in terms of Hankel transform, double Mellin-Barnes integral, and H-functions of two variables. As an application, the fundamental solutions are used to solve a Cauchy problem, and to study telegraph process with Brownian time.publishe

Optical confinement and colour separation in a double colour laser scanned photodiode (D/CLSP)

Large area n-i-p-n-i-p a-SiC:H heterostructures are used as sensing element in a double colour laser scanned photodiode image sensor (D/CLSP). This work aims to clarify possible improvements, physical limits and performance of CLSP image sensor when used as non-pixel image reader. Here, the image capture device and the scanning reader are optimized and the effects of the sensor structure on the output characteristics discussed. The role of the design of the sensing element, the doped layer composition and thickness, the read-out parameters (applied voltage and scanner frequency) on the image acquisition and the colour detection process are analysed. A physical model is presented and supported by a numerical simulation of the output characteristics of the sensor

Some properties of the fractional circle Zernike polynomials

In this paper, we present a fractional extension of the classical circle Zernike polynomials defined via g-Jacobi functions. Some properties of this new class of functions are studied, such as recurrence relations for consecutive and distant neighborhoods, and differential relations. A graphic representation for the proposed fractional circle Zernike polynomials will be presented in the final section of the paper

Contextualizar o saber para a melhoria dos resultados dos alunos

Esta comunicação apresenta um projeto de investigação em curso no Centro de Investigação e Intervenção Educativas da Faculdade de Psicologia e de Ciências da Educação da Universidade do Porto, aprovado pela FCT, e em que colaboram professores das Universidades do Minho, Lisboa e Aveiro. Assente na ideia de que a contextualização curricular é uma condição essencial para a melhoria das aprendizagens dos alunos, estuda-se a presença deste conceito em discursos político-legais, académicos e em práticas curriculares. Para uma compreensão da problemática, apresenta-se uma caracterização do projeto e seus objetivos, os procedimentos metodológicos seguidos e os resultados até agora obtidos

Push-pull heterocyclic dyes based on pyrrole and thiophene: synthesis and evaluation of their optical, redox and photovoltaic properties

Three heterocyclic dyes were synthesized having in mind the changes in the photovoltaic, optical and redox properties by functionalization of 5-aryl-thieno[3,2-b]thiophene, 5-arylthiophene and bis-methylpyrrolylthiophene π-bridges with different donor, acceptor/anchoring groups. Knoevenagel condensation of the aldehyde precursors with 2-cyanoacetic acid was used to prepare the donor-acceptor functionalized heterocyclic molecules. These organic metal-free dyes are constituted by thieno[3,2-b]thiophene, arylthiophene, bis-methylpyrrolylthiophene, spacers and one or two cyanoacetic acid acceptor groups and different electron donor groups (alkoxyl, and pyrrole electron-rich heterocycle). The evaluation of the redox, optical and photovoltaic properties of these compounds indicate that 5-aryl-thieno[3,2-b]thiophene-based dye functionalized with an ethoxyl electron donor and a cyanoacetic acid electron acceptor group/anchoring moiety displays as sensitizer for DSSCs the best conversion efficiency (2.21%). It is mainly assigned to the higher molar extinction coefficient, long π-conjugation of the heterocyclic system, higher oxidation potential and strong electron donating capacity of the ethoxyl group compared to the pirrolyl moiety.Thanks are due to the Fundacao para a Ciencia e Tecnologia (FCT) for a PhD grant to S.S.M. Fernandes (SFRH/BD/87786/2012) and to FEDER-COMPETE for financial support at the research center CQUM (UID/QUI/0686/2016) and (UID/QUI/0686/2020). The NMR spectrometers are part of the National NMR Network (PTNMR) and are partially supported by Infrastructure Project No. 022161 (co-financed by FEDER through COMPETE 2020, POCI and PORL and FCT through PIDDAC). The group in Porto would like to acknowledge the European Commission through the Seventh Framework Programme, the Specific Programme "Ideas" of the European Research Council for research and technological development as part of an Advanced Grant under Grant No. 321315, which also partially funded this work. Some of this work was also performed under the project "SunStorage-Harvesting and storage of solar energy", with reference POCI-01-0145-FEDER-016387, funded by the European Regional Development Fund (ERDF), through COMPETE 2020-Operational Programme for Competitiveness and Internationalization (OPCI), and by national funds, through FCT. The group in Porto is also thankful to POCI-01-0145-FEDER-006939 (Laboratory for Process Engineering, Environment, Biotechnology and Energy-UID/EQU/00511/2013) funded by the European Regional Development Fund (ERDF), through COMPETE2020-Programa Operacional Competitividade e Internacionalizacao (POCI) and by national funds, LEPABE-2-ECO-INNOVATION, supported by the North Portugal Regional Operational Programme (NORTE 2020), under the Portugal 2020 Partnership Agreement, through the European Regional Development Fund (ERD). Institutional Review Board Statement: Not applicable

Synthesis and characterization of novel thieno[3,2-b]thiophene based metal-free organic dyes with different heteroaromatic donor moieties as sensitizers for dye-sensitized solar cells

Four novel heterocycle dyes 3a-d were synthesized in order to study the variations produced in the optical, electronic and photovoltaic properties by substitution of different electron-rich heterocyclic groups to the thieno[3,2-b]thiophene system. The final push-pull conjugated dyes 3a-d were synthesized by Suzuki-Miyaura coupling reaction followed by Knoevenagel condensation of the corresponding aldehyde precursors with cyanoacrylic acid 2a-d. These new push-pull systems are based on a thieno[3,2-b]thiophene spacer, a cyanoacetic acid anchoring group and several electron-rich heterocycles (thiophene, pyrrole and furan) as donor groups. The multidisciplinary study concerning the optical, redox and photovoltaic characterization of the dyes reveals that compound 3b bearing a hexyl-bithiophene donor group/heterocyclic spacer exhibits the best overall conversion efficiency (2.49%) as sensitizer in nanocrystalline TiO2 dye sensitized solar cells. Co-adsorption studies between N719 and 3b revealed that upon addition of N719 co-adsorbent, the optimized cell efficiencies were improved by 16–77%. The best efficiency was 4.40%, corresponding to 54% of the photovoltaic performance of the N719-based DSSC fabricated and measured under similar conditions.FCTFEDERQRENEuropean Research Council (Contract no: 321315

Fundamental solution of the multi-dimensional time fractional telegraph equation

In this paper we study the fundamental solution (FS) of the multidimensional time-fractional telegraph equation with time-fractional derivatives of orders $\alpha \in ]0,1]$ and $\beta \in ]1,2]$ in the Caputo sense. Using the Fourier transform we obtain an integral representation of the FS expressed in terms of a multivariate Mittag-Leffler function in the Fourier domain. The Fourier inversion leads to a double Mellin-Barnes type integral representation and consequently to a H-function of two variables. An explicit series representation of the FS, depending on the parity of the dimension, is also obtained. As an application, we study a telegraph process with Brownian time. Finally, we present some moments of integer order of the FS, and some plots of the FS for some particular values of the dimension $n$ and of the fractional parameters $\alpha$ and $\beta$

Mg2+-doped poly(ε-caprolactone)/siloxane biohybrids

Electrolytes based on a poly(ε-caprolactone) (PCL)/siloxane organic/inorganic host framework doped with magnesium triflate (Mg(CF3SO3)2) were synthesized by the sol-gel process. In the biohybrid matrix short PCL chains are covalently bonded via urethane linkages to the siliceous network. In this study the salt content of samples was identified using the conventional n notation, where n indicates the number of (C(=O)(CH2)5O) PCL repeat units per Mg2+ ion. Materials with compositions ranging from n=∞ to 2 were prepared. The only composition prepared that is not entirely amorphous is that with n = 1. Xerogels with n ≥ 7 are thermally stable up to up to at least 200 ºC. The most conducting ormolyte of the series is that with n = 26 (5.9x10-9 and 9.8x10-7 Scm-1 at 24 and 104 ºC, respectively).Fundação para a Ciência e Tecnologi

Independência funcional e o estado confusional de pessoas sujeitas a programa de reabilitação

Objetivo: conhecer a influência do estado confusional na recuperação da independência funcional do paciente sujeito a reabilitação. Método: estudo descritivo-correlacional, quantitativo e longitudinal, com amostragem não probabilística, de tipologia acidental. Critérios de inclusão: medida de independência funcional ≤90 e pacientes sujeitos a imobilidade. Critérios de exclusão: pacientes portadores de doenças neoplásicas e com uma escala de coma de Glasgow <11. Para a coleta de dados, utilizou-se um questionário sociodemográfico e as escalas NEECHAM e MIF. Resultados: os dados da amostra (n=40), revelam idade de 76,48 anos, em sua maioria mulheres, casadas, com o primeiro ciclo e em média estiveram sujeitos a 49,60 dias de imobilidade. O estado confusional teve uma melhoria significativa da 1ª avaliação na admissão, na qual 52,2% dos indivíduos apresentavam-se com confusão moderada a severa, para a 2ª avaliação na alta, em que 85% apresentavam-se não confusos. A independência funcional registou uma melhoria de 38,03%. Conclusão: a confusão é um problema neuropsiquiátrico que interfere na atenção e a cognição, nomeadamente na capacidade de percepção. No entanto, mesmo os participantes confusos, quando submetidos a um programa de enfermagem de reabilitação tendem a recuperar a independência funcional.Objective: to know the influence of the confusional state in the recovery of the functional independence of the patient undergoing rehabilitation. Method: descriptivecorrelational, quantitative and cross-sectional study, with non-probabilistic sampling, of accidental typology. Inclusion criteria: measure of functional independence ≤90 and patients subject to immobility. Exclusion criteria: patients with neoplastic diseases and with a Glasgow coma scale <11. For data collection, a sociodemographic questionnaire and the NEECHAM and MIF scales were used. Results: the sample data (n = 40), reveal an age of 76.48 years, mostly women, married, with the elementary school and on average were subject to 49.60 days of immobility. The confusional state had a significant improvement from the 1st assessment on admission, in which 52.2% of the individuals presented with moderate to severe confusion, for the 2nd assessment at discharge, in which 85% were not confused. Functional independence improved by 38.03%. Conclusion: confusion is a neuropsychiatric problem that interferes with attention and cognition, namely the capacity for perception. However, even confused participants, when submitted to a rehabilitation nursing program, tend to regain functional independence.Objetivo: conocer la influencia del estado de confusión en la recuperación de la independencia funcional del paciente sometido a rehabilitación. Método: estudio descriptivo-correlacional, cuantitativo y transversal, con muestreo no probabilístico, de tipología accidental. Criterios de inclusión: medida de independencia funcional ≤90 y pacientes sujetos a inmovilidad. Criterios de exclusión: pacientes con enfermedades neoplásicas y con una escala de coma de Glasgow <11. Para la recolección de datos, se utilizó un cuestionario sociodemográfico y las escalas NEECHAM y MIF. Resultados: los datos de la muestra (n = 40) revelan una edad de 76,48 años, en su mayoría mujeres, casadas, con el primer ciclo y en promedio estuvieron sujetas a 49,60 días de inmovilidad. El estado de confusión tuvo una mejoría significativa desde la primera evaluación (52.5%) al ingreso, donde los individuos presentaron confusión de moderada a severa, para la segunda evaluación, día de alta, en la que el 85% no estaba confundido. La independencia funcional mejoró en 38.03%. Conclusión: La confusión es un problema neuropsiquiátrico que interfiere con la atención y la cognición, es decir, la capacidad de percepción. Sin embargo, incluso los participantes confundidos, cuando se someten a un programa de rehabilitación de enfermería, tienden a recuperar la independencia funcional.info:eu-repo/semantics/publishedVersio