Analysis and design of constant-frequency peak-current-controlled high-power-factor boost rectifier with slope compensation

This paper presents the analysis and the design of a peak-current-controlled high-power-factor boost rectifier, with slope compensation, operating at constant frequency. The input current shaping is achieved, with continuous inductor current mode, with no multiplier to generate a current reference. The resulting overall circuitry is very simple, in comparison with the average-current-controlled boost rectifier. Experimental results are presented, taken from a laboratory prototype rated at 370 W and operating at 67 kHz. The measured power factor was 0.99, with a input current THD equal to 5.6%, for an input voltage THD equal to 2.26%.

Computer tools to aid the learning and design steps for photovoltaic systems

This paper presents novel simulation tools to assist the lecturers about learning processes on renewable energy sources, considering photovoltaic (PV) systems. The PV behavior, functionality and its interaction with power electronic converters are investigated in the simulation tools. The main PV output characteristics, I (current) versus V (voltage) and P (power) versus V (voltage), were implemented in the tools, in order to aid the users for the design steps. In order to verify the effectiveness of the developed tools the simulation results were compared with Matlab. Finally, a prototype was implemented with the purpose to compare the experimental results with the results from the proposed tools, validating its operational feasibility. © 2011 IEEE.

Finite element analysis of the influence of geometry and design of zirconia crowns on stress distribution

Purpose: To evaluate the influence of the geometry and design of prosthetic crown preparations on stress distribution in compression tests, using finite element analysis (FEA). Materials and Methods: Six combinations of 3D drawings of all-ceramic crowns (yttria-stabilized zirconia framework and porcelain veneer) were evaluated: F, flat preparation and simplified crown; FC, flat preparation and crown with contact point; FCM, flat preparation and modified crown; A, anatomical preparation and simplified anatomical crown framework; AC, anatomical preparation and crown with contact point; and ACM, anatomical preparation and modified crown. Bonded contact types at all interfaces with the mesh were assigned, and the material properties used were according to the literature. A 200 N vertical load was applied at the center of each model. The maximum principal stresses were quantitatively and qualitatively analyzed. Results: The highest values of tensile stress were observed at the interface between the ceramics in the region under the load application for the simplified models (F and A). Reductions in stress values were observed for the model with the anatomical preparation and modified infrastructure (ACM). The stress distribution in the flat models was similar to that of their respective anatomical models. Conclusions: The modified design of the zirconia coping reduces the stress concentration at the interface with the veneer ceramic, and the simplified preparation can exert a stress distribution similar to that of the anatomical preparation at and near the load point, when load is applied to the center of the crown.

Design and management optimization of trickle irrigation systems using non-linear programming

A non-linear model is presented which optimizes the lay-out, as well as the design and management of trickle irrigation systems, to achieve maximum net benefit. The model consists of an objective function that maximizes profit at the farm level, subject to appropriate geometric and hydraulic constraints. It can be applied to rectangular shaped fields, with uniform or zero slope. The software used is the Gams-Minos package. The basic inputs are the crop-water-production function, the cost function and cost of system components, and design variables. The main outputs are the annual net benefit and pipe diameters and lengths. To illustrate the capability of the model, a sensitivity analysis of the annual net benefit for a citrus field is evaluated with respect to irrigated area, ground slope, micro-sprinkler discharge and shape of the field. The sensitivity analysis suggests that the greatest benefit is obtained with the smallest microsprinkler discharge, the greatest area, a square field and zero ground slope. The costs of the investment and energy are the components of the objective function that had the greatest effect in the 120 situations evaluated. (C) 1996 Academic Press Limited

Improving a process in a brazilian automotive plant applying process mapping, Design of Experiments and Discrete Events Simulation

The objective of this article is to apply the Design of Experiments technique along with the Discrete Events Simulation technique in an automotive process. The benefits of the design of experiments in simulation include the possibility to improve the performance in the simulation process, avoiding trial and error to seek solutions. The methodology of the conjoint use of Design of Experiments and Computer Simulation is presented to assess the effects of the variables and its interactions involved in the process. In this paper, the efficacy of the use of process mapping and design of experiments on the phases of conception and analysis are confirmed.

Design/empresa/sociedade

O presente trabalho se propôs a estudar, através de um levantamento sobre o estado da arte do ensino do design no Brasil, da sua prática pelos designers e da visibilidade das condições daí resultantes, discutir eventuais estratégias que tornem tanto o ensino como os seus produtos condizentes com a realidade nacional sem perda da universalidade. Os resultados estão fortemente subsidiados pelo estágio de pós-doutorado cumprido na Universidade de Arte e Design de Helsinque entre agosto de 2006 e maio de 2007

Artemídia escrevente: a caligrafia entre a arte e o design

The term “writing media art” expresses an artisticscientific process performed in the Art-Science Communication interface presented as Final Paper in Visual Arts baccalaureate modality. The first part gathers, in artistic-scientific research, a historical overview of the relation between image and writing, which its main focus is calligraphy and its different expressions in art and design, including their interrelations. The identification is made from bibliographical and iconographical survey, both printed and virtual materials. This approach involves the selection of authors’ statements and comments in order to offer a deeper historical basis, since it comes to facts and events. The second part relates to the set of works produced during the four-year period of the Visual Arts course, including a reflection about the creation process and all that surrounds it – influences, memories, visions etc. – to finally establish a connection between all these elements in order to make clear this incredible web of creation. This work is inserted in the line of research “Artistic Processes and Procedures” of the Department of Fine Arts of the Art Institute of UNESP and describes: creative process, production and influences. The methodology used was Freinetiana Educational Cybernetics, developed in the research group “Art media and Videoclip”, whose leading advisor is the one from this Final Paper. The result and discussion of the artistic-scientific research were reported in monography in the following versions: PDF File repository for dissemination in the virtual library of the Institute of Arts; hardcover version for physical collection in the Library of the Institute of Arts; paper version for the committee; template version appropriate for submission to International Scientific Congress in the area of Arts

The symbology of the sea in Lygia Bojunga Nunes's work: a reflection on utopian and dystopian framing

The ambivalent image of the sea is recurrent in Bojunga Nunes’s work. It receives a lot of symbolic meanings in her production, being sometimes a positive and sometimes a negative element. Thus, the sea is used in a utopic way, as a place for pleasure and leisure, and in a dystopic way, as scenery of a rite of passage, which includes the pain and suffering, part of the rite of passage that characterizes the bildungsromans. So, if in some texts the sea assumes a utopic character, being a place of snuggle, security, the ideal to reach, in others it is represented as dystopic, a place of distress, asphyxia and death. In this text we will study the hypothesis that, even in its dark symbolic meaning, in the author’s work the sea is an element of reflection and revelation. Thereby, it assumes metaphorically a sense of magnification of the reader’s expectative, being an element of emancipation. The objective of this text is to present a reflection on the sea’s symbolism on the mentioned texts and its importance for the reader’s formation.

A ornamentação contemporânea em arte e design: função estética, anagógica, terapêutica

Taking as a starting point the reflection on the ornament, is delineated an interpretative analysis of delimitation between art and design in the extent of the aesthetics. Presupposing the ornament as an elementary and universal form of the all aesthetics’ manifestations, trying to work, through recent contributions and in an unified way, concepts regarding the aesthetics in parallel with the phenomenon of the perception. The ornament as element previously “ordered” front to the organization need that the interpretation demands, it constitutes fertile philosophical instrument, for all the art forms and of design, which seeks to provide an aesthetic sensation. Returned to the thoughtful function, the ornament has as essential purpose to stimulate the aesthetic experimentation, capable to induce the perception to subtler states of conscience similar of to the ecstasy, where the spirit from whom contemplates, can live experiences of extreme freedom and intense pleasure. . Establishing semiotics foundations capable of evidencing a function anagogic-therapeutics in the action of conceiving and to meditating, alternately, an object with function strictly ornamental (aesthetics), also intending the reflection of moral stamp on the ornamental concept of the decency as conciliatory solution in the intersection between art and design, concerning the creativity of the formative process.

Dos readymade ao design contemporâneo

From Marcel Duchamp’s readymade, tried to establish a historical overview with emphasis on the possible affinities between art and design from modernity, seeking to end weave such a reflection on the contemporary condition.