The problem of professional development of teachers of additional education

В статье рассмотрена проблема профессионального развития педагогов дополнительного образования в условиях высоких требований к качеству работы педагогов, выявлены профессионально-личностные трудности и предложена программа устранения профессиональных затруднений педагогов дополнительного образования.The article considers the problem of professional development of teachers of additional education in the conditions of high requirements to the quality of teachers’ work; it reveals professional and personal difficulties and offers the program of elimination of professional difficulties which teachers of additional education can face

Otimização do processo de moldação para obtenção de peças microestruturadas

Doutoramento em Engenharia MecâncicaAo longo das últimas décadas, a micromoldação (u-moldação) por injeção de termoplásticos ganhou um lugar de destaque no mercado de equipamentos eletrónicos e de uma ampla gama de componentes mecânicos. No entanto, quando o tamanho do componente diminui, os pressupostos geralmente aceites na moldação por injeção convencional deixam de ser válidos para descrever o comportamento reológico e termomecânico do polímero na microimpressão. Por isso, a compreensão do comportamento dinâmico do polímero à escala micro bem como da sua caraterização, análise e previsão das propriedades mecânicas exige uma investigação mais alargada. O objetivo principal deste programa doutoral passa por uma melhor compreensão do fenómeno físico intrínseco ao processo da μ-moldação por injeção. Para cumprir com o objetivo estabelecido, foi efetuado um estudo paramétrico do processo de μ-moldação por injeção, cujos resultados foram comparados com os resultados obtidos por simulação numérica. A caracterização dinâmica mecânica das μ-peças foi efetuada com o objetivo de recolher os dados necessários para a previsão do desempenho mecânico das mesmas, a longo prazo. Finalmente, depois da calibração do modelo matemático do polímero, foram realizadas análises estruturais com o intuito de prever o desempenho mecânico das μ-peças no longo prazo. Verificou-se que o desempenho mecânico das μ-peças pode ser significativamente afetado pelas tensões residuais de origem mecânica e térmica. Estas últimas, resultantes do processo de fabrico e das condições de processamento, por isso, devem ser consideradas na previsão do desempenho mecânico e do tempo de serviço das u-moldações.Over the last decades, microinjection moulding (uIM) of thermoplastics has gained a pertinent place on the market of electronic equipment and a broad range of the mechanical aids. However, when size of components drop to the micro level, the assumptions of the conventional injection moulding cease to describe the complex rheological and thermo-mechanical behavior of the polymer in the microimpression. Therefore, understanding of the polymer flow dynamics at the micro scale as well as characterization, assessment and prediction of the final mechanical properties require a great deal of additional research. The prime objective of this doctoral thesis is to get an insight into the physical phenomena inherent to μIM process. In order to comply with the established objective, a number of parametrical studies of the μIM process were carried on an instrumented micromould and then their results were compared with the obtained numerical simulation results gathered from process modeling phenomena. Dynamical mechanical characterization of μ-moulded parts was performed in order to collect the data required for prediction of their long-term mechanical performance. Finally, after calibration of polymer material model, a long-term transient structural analysis was carried out. It was found out that the structural performance of microparts was significantly affected by the thermo-mechanical (residual) stresses. The latter is an inherent feature of the injection moulding processing, and therefore has to be accounted for the prediction of the u-moulded parts’ service life

CHANGES OF THE OPTICAL PROPERTIES OF TOP-GRADE FLOUR (SEMOLINA) FROM DURUM WHEAT DURING ITS RIPENING

Using the rapid method of digital image analysis by the developed scanning flour analyzer the optical properties of flour (semolina) obtained in laboratory and production conditions from durum wheat of three years of harvest (2017–2019), namely the «yellowness» indicator and the color characteristic in the blue part of the spectrum, were determined. The semolina color was also evaluated by the Konica Minolta CR-410 colorimeter. It is established that the «yellowness» indicator and the color characteristic in the blue part of the spectrum did not change within the first 5 to 6 days after grinding. The change of these indicators for all the samples is observed in the period from 6 to 20 days after grinding, there with the «yellowness» indicator decreased by 25 to 40 relative units, the color characteristic in the blue part of the spectrum increased on average by 133,75 relative units. Over the next three months, there was no change of color (by both indicators). In the course of experimental work the optical properties change depending upon carotenoids content of flour (semolina) during its ripening was shown. The correlation dependence between the «yellowness» indicator of flour (semolina) and its carotenoids content is characterized by a high approximation coefficient. The dependence of the color characteristic of flour in the blue part of the spectrum on the content of carotenoids is characterized by an approximation coefficient equal to 0.9358, and is described as a polynomial equation. It shows, that with a low carotenoid content, the considered indicator is higher by an average of 1100 relative units compared to the color of samples with a carotenoid content from 0.70 to 1.21 mcg/g. At that during storage the optical properties of flour variety with the lowest carotenoids content remained practically the same. During 78 days of storage, there was no significant change of color characteristics of the industrial flour samples, studied from the eleventh day after grinding — 5–8 times higher than the average repeatability of the measurement results.Using the rapid method of digital image analysis by the developed scanning flour analyzer the optical properties of flour (semolina) obtained in laboratory and production conditions from durum wheat of three years of harvest (2017–2019), namely the «yellowness» indicator and the color characteristic in the blue part of the spectrum, were determined. The semolina color was also evaluated by the Konica Minolta CR-410 colorimeter. It is established that the «yellowness» indicator and the color characteristic in the blue part of the spectrum did not change within the first 5 to 6 days after grinding. The change of these indicators for all the samples is observed in the period from 6 to 20 days after grinding, there with the «yellowness» indicator decreased by 25 to 40 relative units, the color characteristic in the blue part of the spectrum increased on average by 133,75 relative units. Over the next three months, there was no change of color (by both indicators). In the course of experimental work the optical properties change depending upon carotenoids content of flour (semolina) during its ripening was shown. The correlation dependence between the «yellowness» indicator of flour (semolina) and its carotenoids content is characterized by a high approximation coefficient. The dependence of the color characteristic of flour in the blue part of the spectrum on the content of carotenoids is characterized by an approximation coefficient equal to 0.9358, and is described as a polynomial equation. It shows, that with a low carotenoid content, the considered indicator is higher by an average of 1100 relative units compared to the color of samples with a carotenoid content from 0.70 to 1.21 mcg/g. At that during storage the optical properties of flour variety with the lowest carotenoids content remained practically the same. During 78 days of storage, there was no significant change of color characteristics of the industrial flour samples, studied from the eleventh day after grinding — 5–8 times higher than the average repeatability of the measurement results

In search of cultural intelligence

In this paper, the main problems of personality formation in modern society are considered. Particular attention is paid to the philosophy of E. Fromm. The modern scientific and technological revolution has led to a radical transformation of all the ideas of mankind about nature, its own role in the world and its capabilities. The lifestyle and needs of people have also changed very much. Technical innovations not only make life easier for people, but also often create a variety of problems. In these conditions, moral and ethical issues come first. These are, mainly, questions that relate to how a modern scientist should behave. And this concerns not only an understanding of the possible consequences of his research, but also positions regarding the existing ideology, political, scientific and religious preferences.В данной работе рассматриваются основные проблемы формирования личности в современном обществе. Особое внимание уделено философии Э. Фромма. Современная научно-техническая революция привела к коренному преобразованию всех представлений человечества о природе, собственной роли в мире и своих возможностях. Образ жизни и потребности людей также очень сильно изменились. Технические инновации не только облегчают жизнь людей, но и часто создают разнообразные проблемы. В этих условиях на первое место выходят вопросы морального и этического характера. Это, главным образом, вопросы, которые касаются того, как должен вести себя современный ученый. Причем это касается не только понимания возможных последствий его исследований, но и позиций относительно существующей идеологии, политических, научных и религиозных предпочтений

Effect of the micromoulding process conditions on polymer flow behavior within a variable thickness microcavity

Fast time to market along with high level of automation and versatility made microinjection moulding, by far, a favorite technique for the mass production of microplastic components. In the microimpressions, very high shear rates develop, eventually leading to excessive shear heating and consequently to less predictable flow behaviour comparing to conventional injection moulding. In this study, the flow behaviour within a variable thickness microimpression is investigated by monitoring pertinent process parameters such as cavity temperature and pressure. A micromoulding insert with a variable thickness was designed, fabricated and instrumented with pressure and temperature sensors. Full factorial design of experiment (DOE) was carried out to optimize the filling of the microimpression. The study with acrylonitrile butadiene styrene (ABS) suggests that the mould temperature plays an important role in the microimpression filling regardless of its thickness. In addition, the microinjection moulding process was monitored in terms of the cavity pressure and temperature, enabling closer assessment of the polymer flow state in the microimpression.Fundação para a Ciência e Tecnologia, project PTDC/EME/TME/66227/2006 and PhD Individual Grant SFRH/BP/45585/2008

On the suitability of the conventional injection moulding process for micro featured parts replication - a doe approach

Injection moulding has proven to be a technology of utmost importance for micro manufacturing because of its highly process automation and low cost. This study investigates the influence of three processing parameters on the replication quality of micro features with high aspect ratio. The filling performance of pin shaped micro features attached to a thin rectangular plate was studied via design of experiments (DOE) approach, considering as input factors: the barrel temperature, mould temperature and injection speed. The polymer chosen for the experiments was polypropylene (PP) and the mould temperature was kept within the conventional range. Furthermore, the results were analysed and compared with the ones obtained via numerical simulation. The latter were obtained by modelling the experimental conditions and performing a 3D analysis, based on the Navier Stokes flow model. The experimental results reveal that the injection speed was the most significant factor affecting the replication of the micro features. In addition, quantitative information extracted from the numerical simulation results was in agreement with the tendency observed experimentally. However, it was found out that the flow lengths of the micro features were under predicted by the numerical simulation, a fact that has been referred in the literature and that may be related to the lack of rheological data to describe the polymer flow in micro channels

Nitroxide malonate methanofullerene as biomimetic model of interaction of nitroxide species with antioxidants

AbstractBis-nitroxide malonate methanofullerene (NO)2-MF was studied as a biomimetic model of reduction–oxidation activity with natural compounds—cytochrome c (cyt c), dihydroquercetin (DHQ), ascorbic acid (AA) and synthetic drug—1-(β-oxyethyl)-4,6-dimethyl-1,2-dihydro-2-oxopyrimidine (xymedon®).(NO)2-MF may be used as the component of Langmuir monolayers on an aqueous subphase and as the adsorbate on silica gel. The activity of (NO)2-MF in the reaction with cyt c was compared with the effect of nitroxide species such as gaseous nitric oxide, 2,2,6,6-tetramethylpiperidine-1-oxyl radical (TEMPO) by using UV–vis and EPR-spectra. It has been shown, that iron(III) in cyt c3+ under action (NO)2-MF was reduced up to iron(II), similar effect was observed under the influence of gaseous NO in aqueous solution, but reduction of iron(III) in heme cyt c was reversible in the presence of TEMPO. Therefore, the state of Fe-heme in cyt c can be used as the indicator of the interaction of cyt c with nitroxide species in vitro.The interaction of cyt c, DHQ, xymedon® with (NO)2-MF monolayers was confirmed by the increasing of limiting area А0 from 0.88nm2 up to 1.70nm2 of (NO)2-MF on the aqueous subphase, by the paramagnetism and UV–vis spectral data changes. These results can be explained by appearance of oxoammonium ion (NO+)2-MF adlayers and monolayers.The antioxidant and regenerating effects were shown when treating wounds by xymedon® in the presence of additives (0.001%) of (NO)2-MF in the experiments on the rats