475 research outputs found
Uso da linguagem RS em robótica
Este artigo destina-se a apresentar a linguagem Reativa Síncrona
RS como ferramenta para o desenvolvimento de software para robótica, tanto
industrial como móvel, criando um mais alto nível de abstração no desenvolvimento
de programas. A linguagem RS tem características que facilitam bastante o
desenvolvimento e manutenção de programas deste tipo, visto que é uma linguagem
reactiva, simples, paralela e distribuída, e de tempo real, características estas que
são importantes para o desenvolvimento deste tipo de programas
Low-Cost Potentiometric Sensor for Chloride Measurement in Continuous Industrial Process Control
Recently, the new updates in legislation about drinking water control and human health have increased the demand for novel electrochemical low-cost sensors, such as potentiometric ones. Nowadays, the determination of chloride ion in aqueous solutions has attracted great attention in several fields, from industrial processes to drinking water control. Indeed, chloride plays a crucial role in corrosion, also influencing the final taste of beverages, especially coffee. The main goal is to obtain devices suitable for continuous and real-time analysis. For these reasons, we investigated the possibility to develop an easy, low-cost potentiometric chloride sensor, able to perform analysis in aqueous mediums for long immersion time and reducing the need of periodic calibration. We realized a chloride ion selective electrode made of Ag/AgCl sintered pellet and we tested its response in model solutions compatible with drinking water. The sensor was able to produce a stable, reproducible, and accurate quantification of chloride in 900 s, without the need for a preliminary calibration test. This opens the route to potential applications of this sensor in continuous, in situ, and real time measurement of chloride ions in industrial processes, with a reduced need for periodic maintenance
Measuring the accuracy of a point system to diagnose tuberculosis in children with a negative smear or with no smear or culture.
In Brazil, a scoring system was adopted to diagnose tuberculosis in childhood. This study determined the accuracy in diagnosing tuberculosis in children with either a negative smear or with no smear or culture conducted in a reference center in João Pessoa Paraíba - Brazil. It is a phase III validation study, using a cross-section design. The study population consisted of 167 patients attending the outpatient clinics suspected of having tuberculosis. The reference standard for the diagnosis of tuberculosis was a blind and independent review of the medical records, radiology and tuberculin test by two experts. Of the 167 patients, 60 were considered to have tuberculosis (by the reference standard diagnostics). The results for the scoring system with the cut-off of 30 points were: sensitivity 78.57% (95%-CI: 65.56-88.41%), specificity 69.16% (95%-CI: 59.50-77.73%), positive predictive value (PPV): 57.14% (95%-CI: 45.35-68.37%), negative predictive value (NPV): 86.05% (95%-CI: 76.89-92.58%), likelihood ratio (+): 2,55, pre-test probability: 34.36%, and post-test probability (+): 57.14%. This supports the current recommendation for the use of this scoring system in Brazil and similar sites with the cut-off of 30 points. However, as the discriminatory power of the point scoring system may vary across settings, it would be advisable to replicate this phase III study in different settings
Analisa Pengaruh Leader-member Exchange Terhadap Kepuasan Kerja Karyawan Melalui Perceived Organizational Support Sebagai Variabel Mediasi Di Restoran De Boliva Surabaya
Penelitian ini ditunjukan untuk menguji Analisa Pengaruh Leader-member Exchange (LMX) Terhadap Kepuasan Kerja Karyawan melalui Perceived Organizational Support (POS) Sebagai Variabel Mediasi di Restoran De Boliva Surabaya. Pengambilan data dilakukan dengan penyebaran kuesioner kepada seluruh responden. Metode Partial Least Square (PLS) digunakan dalam penelitian ini. Hasil penelitian menunjukkan LMX berpengaruh secara positif namun tidak signifikan terhadap Kepuasan Kerja Karyawan, LMX berpengaruh positif dan signifikan terhadap POS, dan POS berpengaruh secara positif dan signifikan terhadap Kepuasan Kerja Karyawan
Interface growth in the channel geometry and tripolar Loewner evolutions
A class of Laplacian growth models in the channel geometry is studied using
the formalism of tripolar Loewner evolutions, in which three points, namely,
the channel corners and infinity, are kept fixed. Initially, the problem of
fingered growth, where growth takes place only at the tips of slit-like
fingers, is revisited and a class of exact exact solutions of the corresponding
Loewner equation is presented for the case of stationary driving functions. A
model for interface growth is then formulated in terms of a generalized
tripolar Loewner equation and several examples are presented, including
interfaces with multiple tips as well as multiple growing interfaces. The model
exhibits interesting dynamical features, such as tip and finger competition.Comment: 9 pages, 11 figure
Turbulence Hierarchy in a Random Fibre Laser
Turbulence is a challenging feature common to a wide range of complex
phenomena. Random fibre lasers are a special class of lasers in which the
feedback arises from multiple scattering in a one-dimensional disordered
cavity-less medium. Here, we report on statistical signatures of turbulence in
the distribution of intensity fluctuations in a continuous-wave-pumped
erbium-based random fibre laser, with random Bragg grating scatterers. The
distribution of intensity fluctuations in an extensive data set exhibits three
qualitatively distinct behaviours: a Gaussian regime below threshold, a mixture
of two distributions with exponentially decaying tails near the threshold, and
a mixture of distributions with stretched-exponential tails above threshold.
All distributions are well described by a hierarchical stochastic model that
incorporates Kolmogorov's theory of turbulence, which includes energy cascade
and the intermittence phenomenon. Our findings have implications for explaining
the remarkably challenging turbulent behaviour in photonics, using a random
fibre laser as the experimental platform.Comment: 9 pages, 5 figure
The management of manufacturing trade-offs
This thesis investigates the nature and management of manufacturing trade-offs. It examines the properties and features of trade-offs in the context of manufacturing systems and the ways that operations management may deal with them.
The need for such an investigation stems from (a) the increasing interest in trade-offs, (b) the implicit use of trade-offs in many recent popular operations literature, (c) the interest in the dynamic competencies literature and (d) the apparent lack of trade-offs methods or an overall framework. This study reflects the need to extend the trade-offs research from its present descriptive focus to an explanatory and hopefully more elucidating focus.
This research is based on a number of case studies of manufacturing companies in Great Britain and Brazil. Data concerning their trade-offs were collected mainly through the examination of documents, observations of shop-floor activities and interviews with the systems' key operations managers. Following analysis identified the major data within and across the cases about the properties, features and management of trade-offs.
This investigation suggests mainly that trade-offs between MSDs do exist; that their structure can be visualised as base, pivot and function; that they are contingent and dynamic; that their performance is different from their importance; that these depend on a range of external and internal factors; that one can improve trade-offs through alternative strategies and that flexibility may have a pivotal role in this process.
The major original contributions of this explanatory, in-depth investigation are (a) the development of a trade-offs model that may be more accurate and useful than previous models in the literature; (b) the distinction between the performance and importance of trade-offs; (c) the taxonomy of trade-offs management strategies and (d) the identification of the role of flexibility in trade-offs management, with emphasis on the distinction between the ideas of flexibility and variety in that context
Cirugía laparoscópica e histeroscópica para embarazo ectópico sobreinfectado en cicatriz de cesárea previa: presentación de un caso
El embarazo ectópico con implantación en la cicatriz de una cesárea previa es un evento muy raro a pesar de la alta tasa de cesárea a nivel mundial, el mecanismo fisiopatológico aún no se establece con claridad. Presentamos un caso de una paciente con diagnóstico de embarazo ectópico sobreinfectado en cicatriz de cesárea previa, tratada con resección quirúrgica de la lesión por histeroscopia y laparoscopia.Ectopic pregnancy implantation in a previous cesarean scar is a very rare condition despite the high caesarean rate worldwide. The pathophysiological mechanism is not yet clearly established. We present a case of a patient with an overinfected ectopic pregnancy, implanted in a previous cesarean scar treated with resection of the lesion by hysteroscopy and laparoscopy
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