Manutenção da umidade do substrato durante o teste de germinação de Brachiaria brizantha

Para avaliar procedimentos para a manutenção da umidade do substrato durante o teste de germinação de Brachiaria brizantha. Estudou-se o efeito da posição das caixas plásticas na câmara de germinação sobre a perda de água semanal, testando-se nove posições verticais (bandejas) e três posições horizontais (porta, meio e fundo do germinador). Foi também avaliado o efeito de procedimentos para manter a umidade do substrato, sobre a germinação, a perda de água semanal e o tempo despendido para a instalação do teste. Os procedimentos testados foram: (a) vedação da caixa plástica com vaselina, (b) vedação com saco plástico dobrado em quatro e colocado entre a tampa e a caixa, (c) colocação da caixa tampada dentro de saco plástico, (d) espuma sob o papel de germinação e (e) testemunha, caixa apenas tampada. Concluiu-se que a câmara de germinação promove a desidratação desigual do substrato conforme a posição das caixas; aquelas localizadas na primeira bandeja superior são as mais prejudicadas. Entre os procedimentos, a vedação com vaselina, a colocação da caixa dentro de saco plástico e a vedação com saco plástico dobrado em quatro entre a tampa e a caixa são eficientes na manutenção da umidade do substrato em taxas que não alteram os resultados do teste de germinação de B. brizantha; os dois últimos procedimentos são os mais rápidos e práticos, adaptando-se à rotina de um laboratório de análise de sementes.

Reflexões sobre a formação clínica fenomenológico-existencial na era da técnica

Phenomenology is the focus of this study for its critique of the limits of positivist science, which guides most of the fields of study including Psychology. The clinical formation process in Psychology courses is especially difficult for students-interns who adopt phenomenology as their clinical framework. Such difficulty is due to the incompatibility between theory provided in Psychology courses a science traditionally based on paradigms of scientism , and the theoretical-methodological proposal adopted by the aforementioned approach. As a backdrop for our study, we carefully examined the thought of philosopher Martin Heidegger, especially the Era of Technique. This contemporary technicism society was studied so that we could understand the socio-cultural status where this formation lies. Thus, we questioned if this panorama upon which Clinical Psychology rests favors the development of a phenomenological attitude and a special look at the meanings of existence, as defined in phenomenological clinical practice. Knowing such limits, our research aimed at understanding the experience of formation of clinical psychologists who take part in internships in the field of phenomenology-existentialism. Such study was, then, a phenomenological-hermeneutic research based on Heideggerian ontology and used a semi-structured interview as access tool. Six students of the UFRN higher-degree Psychology course who were doing their supervised internship in clinical psychology and the referred approach took part in this research. The research revealed that the phenomenological-existential formation phase opens a door to discoveries on the part of the intern that transcend the dimension of the other, for they show a self disclosure while a person in the word. Despite the initial discomforts caused by the course curriculum itself and by the freedom for clinical practice, so characteristic of phenomenology, the narratives demonstrate that such difficulties may start a process of search for new meanings, which show a search for sharpening their practices and for a path in balance with the existence of the other

Participação de moradores no programa de coleta seletiva em três bairros de Natal/RN: explorando determinantes psico-socio-ambientais

The general purpose of the study was the analysis of residents' participation in the program of door-by-door collection of recyclable residuals in Natal, Rio Grande do Norte. Even though the conception of such program by municipal managers was basically aimed at providing job opportunities and income for the collectors, the main objective of the investigation was to verify whether residents' participation could be attributed to their environmental commitment. Data collection involved three municipal districts and was performed in three stages, with complementary methodological strategies (observation, questionnaire, and interview), and characterized by selfevaluation, by residents, and hetero-evaluation, by collectors. Social, demographic, situational/contextual, and dispositional data were identified to help in the analysis of residents' adherence to the program. Separating and delivering recyclable residuals was the most frequent type of residents' participation, which demonstrates their low level of appropriation of decisions related to the program, taking part on it as passive agents. Two forms of motivation towards participating in the program were found: environmental and social. Despite the first being more frequent, it was associated to lack of environmental awareness related to the process, which may very well imply a mere reproduction of pro-environmental discourse. Motivation towards social issues was strongly connected to philanthropic forms of help. Knowledge was revealed as na important predictor for participation, as well as social networks, formed by neighbors, relatives and friends. Despite the social emphasis in the design of the program, it is possible to conclude that some residents also perceive its environmental benefits, possibly as consequence of a knowledge originated outside the program. Initiatives of environmental education should be promoted in order to minimize the allegation of lack of knowledge as justification for non-participation. Similarly, actions to put together municipal management and population would be welcome, to promote joint decisions towards sustainable styles of life

Topological signatures in CMB temperature anisotropy maps

We propose an alternative formalism to simulate cosmic microwave background (CMB) temperature maps in Lambda CDM universes with nontrivial spatial topologies. This formalism avoids the need to explicitly compute the eigenmodes of the Laplacian operator in the spatial sections. Instead, the covariance matrix of the coefficients of the spherical harmonic decomposition of the temperature anisotropies is expressed in terms of the elements of the covering group of the space. We obtain a decomposition of the correlation matrix that isolates the topological contribution to the CMB temperature anisotropies out of the simply connected contribution. A further decomposition of the topological signature of the correlation matrix for an arbitrary topology allows us to compute it in terms of correlation matrices corresponding to simpler topologies, for which closed quadrature formulas might be derived. We also use this decomposition to show that CMB temperature maps of (not too large) multiply connected universes must show patterns of alignment, and propose a method to look for these patterns, thus opening the door to the development of new methods for detecting the topology of our Universe even when the injectivity radius of space is slightly larger than the radius of the last scattering surface. We illustrate all these features with the simplest examples, those of flat homogeneous manifolds, i.e., tori, with special attention given to the cylinder, i.e., T-1 topology.

Tin(II)-EDTA complex: kinetic of thermal decomposition by non-isothermal procedures

Tin on the oxide form, alone or doped with others metals, has been extensively used as gas sensor, thus, this work reports on the preparation and kinetic parameters regarding the thermal decomposition of Sn(II)-ethylenediaminetetraacetate as precursor to SnO2. Thus, the acquaintance with the kinetic model regarding the thermal decomposition of the tin complex may leave the door open to foresee, whether it is possible to get thin film of SnO2 using Sn(II)-EDTA as precursor besides the influence of dopants added.The Sn(II)-EDTA soluble complex was prepared in aqueous medium by adding of tin(II) chloride acid solution to equimolar amount of ammonium salt from EDTA under N-2 atmosphere and temperature of 50degreesC arising the pH similar to 4. The compound was crystallized in ethanol at low-temperature and filtered to eliminate the chloride ions, obtaining the heptacoordinated chelate with the composition H2SnH2O(CH2N(CH2COO)(2))(2).0.5H(2)O.Results from TG, DTG and DSC curves under inert and oxidizing atmospheres indicate the presence of water coordinated to the metal and that the ethylenediamine fraction is thermally more stable than carboxylate groups. The final residue from thermal decomposition was the SnO2 characterized by X-ray as a tetragonal rutile phase.Applying the isoconversional Wall-Flynn-Ozawa method on the DSC curves, average activation energy: E-a = 183.7 +/- 12.7 and 218.9 +/- 2.1 kJ mol(-1), and pre-exponential factor: log A = 18.85 +/- 0.27 and 19.10 +/- 0.27 min(-1), at 95% confidence level, could be obtained, regarding the loss of coordinated water and thermal decomposition of the carboxylate groups, respectively. The E-a and logA also could be obtained applying isoconventional Wall-Flynn method on the TG curves.From E-a and log A values, Dollimore and Malek procedures could be applied suggesting R3 (contracting volume) and SB (two-parameter model) as the kinetic model to the loss of coordinated water (177-244degreesC) and thermal decomposition of the carboxylate groups (283-315degreesC), respectively. Simulated and experimental normalized DTG and DSC curves besides analysis of residuals check these kinetic models. (C) 2003 Elsevier B.V. All rights reserved.

Modeling regional macroeconomic interactions: situation and perspectives for macroeconomic coordination in Latin America. Background paper prepared for the REDIMA workshop on Modeling Macroeconomic Coordination in the Andean Community, (Santiago, Chile 22 October 2003)""

Includes bibliography

Investigação tecnológica de arenitos silicificados da Formação Botucatu (ne do Paraná) para uso como rocha de revestimento

For many years the silicified sandstone associated of the Botucatu Formation has been the target of interest to researchers and miners, either for understanding the genesis of silicification or for your use as dimension stone and covering on the building industry. If in the first there are several articles available in the geological literature the second there are only technical data marketing available. In the northeast portion of the Paraná State and southwest of the São Paulo State these rocks are mined and traded as covering stones. Not much is known about their intrinsic characteristics and technological properties. To improve the knowledge of the technological behavior of these materials, samples from a quarry from Ribeirao Claro region were petrographically and physically characterized according to the standards established by the Brazilian Association of Technical Standards to dimension stones. Therefore, two bulk samples of silicified sandstone of the Ribeirão Claro/PR region were studied and characterized following the norms established by Brazilian Association of Technical Standards for dimension stones. The results obtained in the petrographical and technological studies are presented and indicated that, in general, the technological performance presented by sandstone studied induces limitations of use as covering materials, mainly horizontally as pavements, door stone and step ladder.

The influence of subpixel measurement on digital camera calibration

The aim of this work is to evaluate the influence of point measurements in images, with subpixel accuracy, and its contribution in the calibration of digital cameras. Also, the effect of subpixel measurements in 3D coordinates of check points in the object space will be evaluated. With this purpose, an algorithm that allows subpixel accuracy was implemented for semi-automatic determination of points of interest, based on Fõrstner operator. Experiments were accomplished with a block of images acquired with the multispectral camera DuncanTech MS3100-CIR. The influence of subpixel measurements in the adjustment by Least Square Method (LSM) was evaluated by the comparison of estimated standard deviation of parameters in both situations, with manual measurement (pixel accuracy) and with subpixel estimation. Additionally, the influence of subpixel measurements in the 3D reconstruction was also analyzed. Based on the obtained results, i.e., on the quantification of the standard deviation reduction in the Inner Orientation Parameters (IOP) and also in the relative error of the 3D reconstruction, it was shown that measurements with subpixel accuracy are relevant for some tasks in Photogrammetry, mainly for those in which the metric quality is of great relevance, as Camera Calibration.

Fuzzy control embedded in microcontroller and applied to an experimental apparatus using magnetorheological fluid damper

This work focuses on applying fuzzy control embedded in microcontrollers in an experimental apparatus using magnetorheological fluid damper. The non-linear behavior of the magnetorheological dampers associated with the parametric variations on vehicle suspension models corroborate the use of the fuzzy controllers. The fundamental formulation of this controller is discussed and its performance is shown through numeric simulations. An experimental apparatus representing a two degree of freedom system containing a magnetorheological damper is used to identify the main parameters and to evaluate the performance of the closed-loop system with the embedded low-cost microcontroller-based fuzzy controller. © 2013 Brazilian Society for Automatics - SBA.

Stability of nonlinear system using takagi-sugeno fuzzy models and hyper-rectangle of LMIs

This paper presents a theorem based on the hyper-rectangle defined by the closed set of the time derivatives of the membership functions of Takagi-Sugeno fuzzy systems. This result is also based on Linear Matrix Inequalities and allows the reduction of the conservatism of the stability analysis in the sense of Lyapunov. The theorem generalizes previous results available in the literature. © 2013 Brazilian Society for Automatics - SBA.

Multiobjective short-term planning of electric power distribution systems using NSGA-II

This paper presents a mixed integer nonlinear programming multiobjective model for short-term planning of distribution networks that considers in an integrated manner the following planning activities: allocation of capacitor banks; voltage regulators; the cable replacement of branches and feeders. The objective functions considered in the proposed model are: to minimize operational and investment costs and minimize the voltage deviations in the the network buses, subject to a set of technical and operational constraints. A multiobjective genetic algorithm based on a Non-Dominated Sorting Genetic Algorithm (NSGA-II) is proposed to solve this model. The proposed mathematical model and solution methodology is validated testing a medium voltage distribution system with 135 buses. © 2013 Brazilian Society for Automatics - SBA.

Artificial neural network model of discharge lamps in the power quality context

This paper presents a methodology for modeling high intensity discharge lamps based on artificial neural networks. The methodology provides a model which is able to represent the device operating in the frequency of distribution systems, facing events related to power quality. With the aid of a data acquisition system to monitor the laboratory experiment, and using $$\text{ MATLAB }^{\textregistered }$$ software, data was obtained for the training of two neural networks. These neural networks, working together, were able to represent with high fidelity the behavior of a discharge lamp. The excellent performance obtained by these models allowed the simulation of a group of lamps in a distribution system with shorter simulation time when compared to mathematical models. This fact justified the application of this family of loads in electric power systems. The representation of the device facing power quality disturbances also proved to be a useful tool for more complex studies in distribution systems. © 2013 Brazilian Society for Automatics - SBA.

Sparse arrays and image compounding techniques for non-destructive testing using guided acoustic waves

Piezoelectric array transducers applications are becoming usual in the ultrasonic non-destructive testing area. However, the number of elements can increase the system complexity, due to the necessity of multichannel circuitry and to the large amount of data to be processed. Synthetic aperture techniques, where one or few transmission and reception channels are necessary, and the data are post-processed, can be used to reduce the system complexity. Another possibility is to use sparse arrays instead of a full-populated array. In sparse arrays, there is a smaller number of elements and the interelement spacing is larger than half wavelength. In this work, results of ultrasonic inspection of an aluminum plate with artificial defects using guided acoustic waves and sparse arrays are presented. Synthetic aperture techniques are used to obtain a set of images that are then processed with an image compounding technique, which was previously evaluated only with full-populated arrays, in order to increase the resolution and contrast of the images. The results with sparse arrays are equivalent to the ones obtained with full-populated arrays in terms of resolution. Although there is an 8 dB contrast reduction when using sparse arrays, defect detection is preserved and there is the advantage of a reduction in the number of transducer elements and data volume. © 2013 Brazilian Society for Automatics - SBA.

Nonlinear control system applied to atomic force microscope including parametric errors

The performance of the optimal linear feedback control and of the state-dependent Riccati equation control techniques applied to control and to suppress the chaotic motion in the atomic force microscope are analyzed. In addition, the sensitivity of each control technique regarding to parametric uncertainties are considered. Simulation results show the advantages and disadvantages of each technique. © 2013 Brazilian Society for Automatics - SBA.

Decoupled reference generator for shunt active filters using the conservative power theory

Based on the framework of the Conservative Power Theory (CPT), this paper proposes some compensation strategies for shunt current compensators. CPT current decompositions result in several current-related terms associated with specific load characteristics, such as power consumption, energy storage, unbalances and load nonlinearities. These current components are decoupled (orthogonal) from each other and are used here to define different compensation strategies, which can be selective in minimizing particular effects of disturbing loads. Compensation strategies for single- and three-phase four-wire circuits are also considered. Simulated and experimental results are described to validate the possibilities and performance of the proposed strategies. © 2013 Brazilian Society for Automatics - SBA.