Decisões de financiamento das micro empresas nacionais

Este trabalho tem como objectivo analisar as fontes de financiamento e a estrutura de capital de uma amostra de 131 micro empresas de Portugal, para o período de 2005-2009. Verificamos que o crescimento de m/l-prazo, das empresas é financiado por intermédio de origens de fundos com a mesma maturidade, concluindo se que as empresas seguem a teoria do equilíbrio financeiro mínimo. A relação negativa, entre as origens de médio longo prazo e a rendibilidade dos capitais próprios, leva-nos a concluir que as empresas seguem a teoria pecking order. As empresas mais velhas tendem a apresentar uma maior prevalência de capitais permanentes

Financing decisions of portuguese micro-enterprises

This paper seeks to analyze the sources of finance and capital structure of a sample of 131 small firms in Portugal, in the districts of Vila Real, Bragança, Guarda and Castelo Branco, for the period 2005 to 2009. The firms were randomly selected, and the data were collected from the accounting documents prepared for fiscal purpose. Due to the firms’ different capital structures, we divided the research sample in three sub-samples as a function of negative, near zero and positive working capital. The importance of funding sources was measured by the dependent variable of medium-long term sources, while capital structure was assessed through the dependent variables of permanent capital/total assets, non-current liabilities/total assets. The independent variables considered were firm growth, non-current asset ageing and return on equity. For data processing, we used a multi-variate linear regression, taking the mean values of each variable in the period 2005 to 2009. We found that the medium-long term growth of the firms is financed by sources of finance with the same maturity, concluding that firms follow the principle of minimum financial balance. The negative relationship between medium-long term sources and return on equity, allows us to conclude that firms follow the Pecking Order Theory. Non-current asset ageing has a positive relationship with the ratio of capital structure, meaning that older firms tend to have a higher level of permanent capital. Additionally, these results allow us to conclude that, although developed primarily for large enterprises, capital structure theories are also applicable to the micro firms analyzed

Making sense of light: the use of optical spectroscopy techniques in plant sciences and agriculture

As a result of the development of non-invasive optical spectroscopy, the number of prospective technologies of plant monitoring is growing. Being implemented in devices with different functions and hardware, these technologies are increasingly using the most advanced data processing algorithms, including machine learning and more available computing power each time. Optical spectroscopy is widely used to evaluate plant tissues, diagnose crops, and study the response of plants to biotic and abiotic stress. Spectral methods can also assist in remote and non-invasive assessment of the physiology of photosynthetic biofilms and the impact of plant species on biodiversity and ecosystem stability. The emergence of high-throughput technologies for plant phenotyping and the accompanying need for methods for rapid and non-contact assessment of plant productivity has generated renewed interest in the application of optical spectroscopy in fundamental plant sciences and agriculture. In this perspective paper, starting with a brief overview of the scientific and technological backgrounds of optical spectroscopy and current mainstream techniques and applications, we foresee the future development of this family of optical spectroscopic methodologies.info:eu-repo/semantics/publishedVersio

SLaMA-URM method for the seismic vulnerability assessment of UnReinforced Masonry structures: Formulation and validation for a substructure

An analytical procedure based on the SLaMA (Simplified Lateral Mechanism Analysis) method is proposed for the seismic vulnerability assessment of UnReinforced Masonry (URM) structures. The procedure considers an equivalent frame discretization for the structure (pier, spandrel, and joint elements) and includes: (i) the evaluation of moment‒rotation capacity curves at each pier-spandrel subassembly; (ii) the assessment of the hierarchy of strength in each subassembly; and (iii) the calculation of the structure capacity curve according to the expected failure mechanism. Validation of the proposed SLaMA-URM procedure is achieved in a one-story URM substructure tested under lateral cyclic loading. The analytical predictions are compared with numerical ones from a 2D continuous finite element (FE) model based on a macro-modelling strategy. The flexural capacity of the components is estimated using a monolithic beam analogy, and the results compared with those from traditional sectional analysis. The influence of the substructure geometry on the hierarchy of strength at the subassembly and global levels is investigated. An analytical formulation of the pier-spandrel joint strength is also proposed to be considered in the assessment of the hierarchy of strength. The method is validated for a one-story substructure subjected to lateral in-plane loading. Results, in terms of crack patterns and capacity curves, are in relatively good agreement with the experimental and FE results, even when a bilinear curve approximation is used. The potential of the SLaMA-URM method for the seismic assessment of URM buildings is demonstrated, whose application to a larger URM structure is planned as a subsequent study

A time of flight method to measure the speed of sound using a stereo sound card

We present an inexpensive apparatus for measuring the speed of sound, with a time of flight method, using a computer with a stereo sound board. Students measure the speed of sound by timing the delay between the arrivals of a pulse to two microphones placed at different distances from the source. It can serve as a very effective demonstration, providing a quick measurement of the speed of sound in air; we have used it with great success in Open Days in our Department. It can also be used for a full fledged laboratory determination of the speed of sound in air.Comment: Accepted for publication in The Physics Teache

The applications of cold atmospheric plasma in dentistry

ACKNOWLEDGMENTSNeusa Silva sincerely acknowledges Fundação para aCiência e a Tecnologia (FCT) for the PhD Scholarship—Cold Atmospheric Plasma for periodontal and peri‐implant disease treatment: antibacterial effects andcellular response, 2022. 13655. BD. The authors alsothank the research center Grants N°. UIDP/FIS/04559/2020 (LIBPhys), from FCT, Portugal.Cold atmospheric plasma (CAP), as a noninvasive technology, has shown promise in dentistry as it might successfully treat various oral conditions. The antimicrobial capacity of CAP has been proven and it is effective in reducing the main microorganisms responsible for oral infections. Furthermore, CAP has also been explored in the field of tissue regeneration with a great response from both soft and hard tissue. The surface modification ability of CAP is another area of interest, revealing a potential improvement in the osseointegration of dental implants. Additionally, there are other areas within dentistry that have studied the use of CAP, such as surface disinfection, bleaching, and cavity preparation.info:eu-repo/semantics/publishedVersio

Polymer optical fiber specklegram strain sensor with extended dynamic range

FAPESP - FUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULOCNPQ - CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICOCAPES - COORDENAÇÃO DE APERFEIÇOAMENTO DE PESSOAL E NÍVEL SUPERIORA polymer optical fiber strain sensor with extended dynamic range is reported. The proposed algorithm resets the reference fiber status depending on the magnitude of the specklegram deviation so the correlation coefficient never saturates, yielding a continuous response over the full range for both positive and negative strains. The technique was evaluated on the measurement of axial strains using a ZEONEX core, poly(methyl methacrylate) cladding multimode fiber, presenting reproducible results with 3 x 10(-3) mu epsilon(-1) sensitivity (similar to 15 mu epsilon resolution) within a 22,600 mu epsilon interval. In contrast to the available approaches, the presented method can retrieve the strain direction and does not require intensive image processing, thus providing a simple and reliable technique for mechanical measurements using multimode optical fibers. (C) 2018 Society of Photo-Optical Instrumentation Engineers (SPIE)571119FAPESP - FUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULOCNPQ - CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICOCAPES - COORDENAÇÃO DE APERFEIÇOAMENTO DE PESSOAL E NÍVEL SUPERIORFAPESP - FUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULOCNPQ - CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICOCAPES - COORDENAÇÃO DE APERFEIÇOAMENTO DE PESSOAL E NÍVEL SUPERIOR2014/50632-62017/25666-2sem informaçãosem informaçã

Machine learning recognition of light orbital-angular-momentum superpositions

We developed a method to characterize arbitrary superpositions of light orbital angular momentum (OAM) with high fidelity by using astigmatic tomography and machine learning processing. In order to define each superposition unequivocally, we combine two intensity measurements. The first one is the direct image of the input beam, which cannot distinguish between opposite OAM components. This ambiguity is removed by a second image obtained after astigmatic transformation of the input beam. Samples of these image pairs are used to train a convolution neural network and achieve high fidelity recognition of arbitrary OAM superpositions with dimension up to five