Effects of synthesis parameters on the properties and photocatalytic activity of the magnetic catalyst TiO2/CoFe2O4 applied to selenium photoreduction

intake to human health. Heterogeneous photocatalysis can be successfully applied to remove selenium ions from water, but the photocatalyst recovery in the end of the process still needs improvement. The application of a magnetic photocatalyst (TiO2/CoFe2O4) in the Se(IV) photoreduction was investigated, with emphasis in the catalyst magnetic separation. The photocatalyst was synthetized via a simple sol-gel method and a central composite design was considered to evaluate the effects of titanium isopropoxide mass ratio used in the synthesis, calcination temperature and pH on Se(IV) reduction. Calcination temperature showed a strong influence in the photocatalytic activity, and the catalyst calcined at 381 ◦C presented the best performance. In the bests test, at pH 2.61, it was possible to remove >99% selenium after 2 min of exposure to radiation. Photocatalysts containing great amounts of rutile phase produced the lowest removal results. The TiO2/CoFe2O4 photocatalyst was magnetically separable, however its saturation magnetization (2.7 emu g 1) was considerably smaller than pure CoFe2O4 (84.6 emu g 1) and the photocatalyst magnetic separation from the aqueous medium was about 11 times slower in comparison to pure cobalt ferrite. The synthetized photocatalyst was able to satisfactorily photoreduce Se(IV) (96.5%) even after five cycles of photocatalysis

On positioning and vibration control application to robotic manipulators with a nonideal load carrying

In recent years, the evolution of artificial intelligence techniques has widely grown such that it gives new ways to improve human life, not only at work but also living. Nowadays, to the human being, physical human-robot interactions (PHRIs) have been presented very important and present itself as a major challenge for the current engineering. Therefore, this work designs and analyses a two-degree-of-freedom robotic arm with flexible joints driven by a DC motor. Due to the interaction between the robot links and flexible joints, the arm may present overshoots when it is moved such that it becomes difficult to manipulate the arm. Therefore, Magnetorheological dampers (MR damper or MR brake) are attached to the links of the arm in order to control such overshoot and provide a way to adjust the mechanical limitations of the arm. The dynamics of the system will be investigated, showing the appearance of chaotic behavior due to the coupling of the manipulator to the motors. After that, the feedback control is obtained through the state-dependent Riccati equation (SDRE) aiming the control of the positioning of the manipulator and the torque applied on the MR damper. Numerical results showed that the proposed control using hybrid actuators, DC motor, and MR brake was effective to control the position and behavior of the flexible joints of the manipulators

Women's refolution at work

The renowned Age of Revolution encompasses the period between the American Revolution (1776) and the so-called Spring of Nations in 1848, this being the height of the revolutionary movements in Europe in the 19th century, though it may be considered just the tip of the iceberg as far as civil rights movements for people from all walks of life are concerned. The changes that occurred throughout this timespan intended to move from feudal and absolutist systems, considered old-fashioned and ill-suited, to constitutionalist states and republics that would be able to heed the new values, e.g. liberalism, nationalism and socialism, as well as the demands of the working classes, enduring the harmful effects of industrialisation. Working people had been flowing into large industrial cities for over a century since the onset of the Industrial Revolution, leaving behind their home places and settling in overcrowded, rundown dwellings in appalling living conditions. The shift from working at home to working in factories brought along a number of issues that would be the motivation for setting up trade unions, namely the long working hours (between 12 and 14 hours per day), the low wages, the cruel discipline and the fierce system of fines that was applied, and the numerous accidents and health issues that ensued. Despite the overall negative conditions, women and children were among those who suffered the most, especially because the former’s wages were regarded as secondary earnings and thus less important than men’s. Consequently, from 1850s onwards, trade unions began to fight for better paid workers and women were initially excluded from these structures be it as members or leaders, being supported by social reformers instead. As a case in point, it is worth mentioning Clementina Black who, in 1888, set forth a demand for equal pay between men and women in the UK and the Bryant and May match factory strike which was held in the same year. Bearing in mind this social and historical context, our aim with this paper is two-fold: not only do we seek to focus on unionist movements in the last half of the 19th century in the European context as a means to fight against conservative and slavery-like practices in the workplace but we also wish to emphasise the place and importance of working-class women in this general workers’ assertion, particularly in their attempt to gain equal pay, a true refolution that would be the motivational beacon for 20th century movements, such as that of the suffragettes.info:eu-repo/semantics/publishedVersio

Individual Rights, Economic Transactions, and Recognition: A Legal Approach to Social Economics

Modernity brought the idea of individual property rights as a com- plex phenomenon. However, economics adopted a simplistic view of property as a fundamental institution, understating the complex interaction of different rights and obligations that frame the legal environment of economic processes with an insufficiently elaborated tool. Here, a more elaborate view of legal elements will be propose

Mutational analysis of TAC3 and TACR3 genes in patients with idiopathic central pubertal disorders

OBJETIVO: Investigar a presença de variantes nos genes TAC3 e TACR3, os quais codificam a NKB e seu receptor (NK3R), respectivamente, em uma coorte de pacientes com distúrbios puberais centrais idiopáticos. \ud SUJEITOS E MÉTODOS: Duzentos e trinta e sete pacientes foram estudados: 114 com puberdade precoce central (PPC), 73 com hipogonadismo hipogonadotrófico isolado normósmico (HHI) e 50 com retardo constitucional do crescimento e desenvolvimento (RCCD). O grupo controle consistiu de 150 indivíduos brasileiros que apresentaram desenvolvimento puberal normal. O DNA genômico foi extraído de sangue periférico, e as regiões codificadoras dos genes TAC3 e TACR3 foram amplificadas e sequenciadas automaticamente. \ud RESULTADOS: Uma variante (p.A63P) foi identificada na NKB, e quatro variantes, p.G18D, p.L58L (c.172C>T), p.W275X e p.A449S, foram identificadas no NK3R, as quais foram ausentes no grupo controle. A variante p.A63P foi identificada em uma menina com PPC, e a variante p.A449S, em uma menina com RCCD. As variantes previamente descritas, p.G18D, p.L58L e p.W275X, foram identificadas em três indivíduos com HHI normósmico do sexo masculino não relacionados. \ud CONCLUSÃO: Variantes raras nos genes TAC3 e TACR3 foram identificadas em pacientes com distúrbios puberais centrais idiopáticos. Mutações de perda de função no gene TACR3 foram associadas com o fenótipo de HHI normósmico. Arq Bras Endocrinol Metab. 2012;56(9):646-52Objective: To investigate the presence of variants in the TAC3 and TACR3 genes, which encode NKB and its receptor (NK3R), respectively, in a large cohort of patients with idiopathic central pubertal disorders. Subjects and methods: Two hundred and thirty seven patients were studied: 114 with central precocious puberty (CPP), 73 with normosmic isolated hypogonadotropic hypogonadism (IHH), and 50 with constitutional delay of growth and puberty (CDGP). The control group consisted of 150 Brazilian individuals with normal pubertal development. Genomic DNA was extracted from peripheral blood and the entire coding region of both TAC3 and TACR3 genes were amplified and automatically sequenced. Results: We identified one variant (p.A63P) in NKB and four variants, p.G18D, p.L58L (c.172C > T), p.W275* and p.A449S in NK3R, which were absent in the control group. The p.A63P variant was identified in a girl with CPP, and p.A449S in a girl with CDGP. The known p.G18D, p.L58L, and p.W275* variants were identified in three unrelated males with normosmic IHH. Conclusion: Rare variants in the TAC3 and TACR3 genes were identified in patients with central pubertal disorders. Loss-of-function variants of TACR3 were associated with the normosmic IHH phenotype. Arq Bras Endocrinol Metab. 2012; 56(9):646-52FAPESPFapesp [05/04726]Conselho Nacional de Desenvolvimento Cientifico e Tecnologico (CNPq) [302825/2011-8, 305743/2011-8]Conselho Nacional de Desenvolvimento Cientifico e Tecnologico (CNPq)Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health (NIH)Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health (NIH) [U54 HD28138

Dynamical Analysis and Control of a Chaotic Microelectromechanical Resonator Model

The dynamic analysis and control of a nonlinear MEM resonator system are considered. Phase diagram, bifurcation diagram, and the 0-1 test are applied to the analysis of the influence of the parameters on the dynamics of the system, whose parameters are damping coefficient, polarization of the voltage, and nonlinear stiffness term. The bifurcation diagram is used to demonstrate the existence of the pull-in effect. Numerical results showed that the parameters, which were taken into account, were significant, indicating that the response can be either chaotic or periodic behavior. In order to bring the system from a chaotic state to a periodic orbit, two controls are considered: the time-delayed feedback control and the sliding mode control

On nonlinear dynamic of a non-ideal Duffing system with fractional damping

Fractional damping is appearing in different contexts in any systems with memory and hysteresis. Such damping is defined by a fractional derivative term, in contrary to classical viscous damping which takes into account the first order derivative. In this work, we characterize the nonlinear dynamics of a non-ideal Duffing system, with fractional damping using nonlinear dynamical tools. The non-ideal excitation originates from a DC electric motor with limited power supply driving an unbalanced rotating mass. The response of the system is investigated with the voltage as a control parameter. Numerical simulations show the occurrence of regular and non-regular motions, which are investigated via bifurcation diagramoccurrence diagrams and phase plane portraits