41 resultados para Trabalhos em madeira - Ferramentas

em Universidade Federal do Rio Grande do Norte(UFRN)


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This thesis aims to describe and demonstrate the developed concept to facilitate the use of thermal simulation tools during the building design process. Despite the impact of architectural elements on the performance of buildings, some influential decisions are frequently based solely on qualitative information. Even though such design support is adequate for most decisions, the designer will eventually have doubts concerning the performance of some design decisions. These situations will require some kind of additional knowledge to be properly approached. The concept of designerly ways of simulating focuses on the formulation and solution of design dilemmas, which are doubts about the design that cannot be fully understood nor solved without using quantitative information. The concept intends to combine the power of analysis from computer simulation tools with the capacity of synthesis from architects. Three types of simulation tools are considered: solar analysis, thermal/energy simulation and CFD. Design dilemmas are formulated and framed according to the architect s reflection process about performance aspects. Throughout the thesis, the problem is investigated in three fields: professional, technical and theoretical fields. This approach on distinct parts of the problem aimed to i) characterize different professional categories with regards to their design practice and use of tools, ii) investigate preceding researchers on the use of simulation tools and iii) draw analogies between the proposed concept, and some concepts developed or described in previous works about design theory. The proposed concept was tested in eight design dilemmas extracted from three case studies in the Netherlands. The three investigated processes are houses designed by Dutch architectural firms. Relevant information and criteria from each case study were obtained through interviews and conversations with the involved architects. The practical application, despite its success in the research context, allowed the identification of some applicability limitations of the concept, concerning the architects need to have technical knowledge and the actual evolution stage of simulation tools

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This work presents the results, analyses and conclusions about a study carried out with objective of minimizing the thermal cracks formation on cemented carbide inserts during face milling. The main focus of investigation was based on the observation that milling process is an interrupted machining process, which imposes cyclic thermal loads to the cutting tool, causing frequent stresses changes in its superficial and sub-superficial layers. These characteristics cause the formation of perpendicular cracks from cutting edge which aid the cutting tool wear, reducing its life. Several works on this subject emphasizing the thermal cyclic behavior imposed by the milling process as the main responsible for thermal cracks formation have been published. In these cases, the phenomenon appears as a consequence of the difference in temperature experienced by the cutting tool with each rotation of the cutter, usually defined as the difference between the temperatures in the cutting tool wedge at the end of the cutting and idle periods (T factor). Thus, a technique to minimize this cyclic behavior with objective of transforming the milling in an almost-continuous process in terms of temperature was proposed. In this case, a hot air stream was applied into the idle period, during the machining process. This procedure aimed to minimize the T factor. This technique was applied using three values of temperature from the hot air stream (100, 350 e 580 oC) with no cutting fluid (dry condition) and with cutting fluid mist (wet condition) using the hot air stream at 580oC. Besides, trials at room temperature were carried out. Afterwards the inserts were analyzed using a scanning electron microscope, where the quantity of thermal cracks generated in each condition, the wear and others damages was analyzed. In a general way, it was found that the heating of the idle period was positive for reducing the number of thermal cracks during face milling with cemented carbide inserts. Further, the cutting fluid mist application was effective in reducing the wear of the cutting tools.

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This thesis aims to describe and demonstrate the developed concept to facilitate the use of thermal simulation tools during the building design process. Despite the impact of architectural elements on the performance of buildings, some influential decisions are frequently based solely on qualitative information. Even though such design support is adequate for most decisions, the designer will eventually have doubts concerning the performance of some design decisions. These situations will require some kind of additional knowledge to be properly approached. The concept of designerly ways of simulating focuses on the formulation and solution of design dilemmas, which are doubts about the design that cannot be fully understood nor solved without using quantitative information. The concept intends to combine the power of analysis from computer simulation tools with the capacity of synthesis from architects. Three types of simulation tools are considered: solar analysis, thermal/energy simulation and CFD. Design dilemmas are formulated and framed according to the architect s reflection process about performance aspects. Throughout the thesis, the problem is investigated in three fields: professional, technical and theoretical fields. This approach on distinct parts of the problem aimed to i) characterize different professional categories with regards to their design practice and use of tools, ii) investigate preceding researchers on the use of simulation tools and iii) draw analogies between the proposed concept, and some concepts developed or described in previous works about design theory. The proposed concept was tested in eight design dilemmas extracted from three case studies in the Netherlands. The three investigated processes are houses designed by Dutch architectural firms. Relevant information and criteria from each case study were obtained through interviews and conversations with the involved architects. The practical application, despite its success in the research context, allowed the identification of some applicability limitations of the concept, concerning the architects need to have technical knowledge and the actual evolution stage of simulation tools

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This work regards to the structural conception as a formal element of design in wood architecture. On this approach, the group of projects studied is formed by some realized works of two important Brazilian architects: Severiano Porto and Marcos Acayaba. The time interval comprises the period from 1971 to 1997, which correspond respectively to the years of the creation of first and the last of the analyzed constructions. The research perspective concerns to the relationship between the parts, the whole and the building techniques adopted in each project. Moreover, the analysis focuses on the structure as the link among the different projectual ideas. Thus, the research method firstly includes a survey of specific bibliographies and documents which refer to the structural conception in wood architecture. Secondly,the buildings are analyzed according to the methods of architectural composition discussed through this work.

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This research continues the current debate about the role of the images and the words in the architectural design persuasion, where we emphasize the increasing valuation of written documents (FORTY, 2004; MARKUS; CAMERON, 2002), the seduction for the graphical representation (DURAND, 2003) and the rhetorical effects of the graphical and textual resources (TOSTRUP, 1999). Based on these quarrels, we look for verify in the graduate final projects the relation between the design texts and images. From the PROJEDATA, database of the PROJETAR research group (UFRN), we selected the final projects of two brazilians universities, UFRN and USP, that in a first analysis, they had shown as ideal types of two distinct design presentation models, respectively: texts and drawings in separated documents, or combined in an only support. Based on Markus explanation about the function and the content of the texts, on the Durand perspective with regard to graphical representation uses and on Tostrup point of view concerning the rhetorical potential of texts and drawings, we analyze, in a set of 25 projects, how the students relate the textual and imagetical speeches. For this, we related the focus of each speech, in order to verify the possible coherence between both. We conclude that in the model of USP final project the coherence between the texts and the drawings is clearer than in the model adopted in UFRN

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The building envelope is the principal mean of interaction between indoors and environment, with direct influence on thermal and energy performance of the building. By intervening in the envelope, with the proposal of specific architectural elements, it is possible to promote the use of passive strategies of conditioning, such as natural ventilation. The cross ventilation is recommended by the NBR 15220-3 as the bioclimatic main strategy for the hot and humid climate of Natal/RN, offering among other benefits, the thermal comfort of occupants. The analysis tools of natural ventilation, on the other hand, cover a variety of techniques, from the simplified calculation methods to computer fluid dynamics, whose limitations are discussed in several papers, but without detailing the problems encountered. In this sense, the present study aims to evaluate the potential of wind catchers, envelope elements used to increase natural ventilation in the building, through CFD simplified simulation. Moreover, it seeks to quantify the limitations encountered during the analysis. For this, the procedure adopted to evaluate the elements implementation and efficiency was the CFD simulation, abbreviation for Computer Fluid Dynamics, with the software DesignBuilder CFD. It was defined a base case, where wind catchers were added with various settings, to compare them with each other and appreciate the differences in flows and air speeds encountered. Initially there has been done sensitivity tests for familiarization with the software and observe simulation patterns, mapping the settings used and simulation time for each case simulated. The results show the limitations encountered during the simulation process, as well as an overview of the efficiency and potential of wind catchers, with the increase of ventilation with the use of catchers, differences in air flow patterns and significant increase in air speeds indoors, besides changes found due to different element geometries. It is considered that the software used can help designers during preliminary analysis in the early stages of design

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This research is about the use of the coconut´s endocarp (nucifera linn) and the waste of derivatives of wood and furniture as raw material to technological use. In that sense, the lignocellulosic waste is used for manufacture of homogeneous wood sheet agglomerate (LHWS) and lignocellulosic load which take part of a polymeric composite with fiber glass E (GFRP-WC). In the manufacturing of the homogeneous wood sheet agglomerate (LHWS), it was used mamona´s resin as waste s agglutinating element. The plates were taken up in a hydraulic press engine, heated, with temperature control, where they were manufactured for different percentage of waste wood and coconuts nucífera linn. Physical tests were conducted to determine the absorption of water, density, damp grade (in two hours and twenty-four hours), swelling thickness (in two hours and twenty-four hours), and mechanical tests to evaluate the parallel tensile strength (internal stick) and bending and the static (steady) flexural. The physical test´s results indicate that the LHWS can be classified as bonded wood plate of high-density and with highly water resistant. In the mechanical tests it was possible to establish that LHWS presents different characteristics when submitted to uniaxial tensile and to the static (steady) flexural, since brittle and elasticity module had a variation according to the amount of dry endocarp used to manufacture each trace of LHWS. The GFRP-WC was industrially manufactured by a hand-lay-up process where the fiber glass E was used as reinforcement the lignocellulósic´s waste as load. The matrix was made with ortofitalic unsaturated polyester resin. Physical and mechanical tests were performed in presence of saturated humidity and dry. The results indicated good performance of the GFRP-WC, as traction as in flexion in three points. The presence of water influenced the modules obtained in the flexural and tensile but there were no significant alteration in the properties analyzed. As for the fracture, the analysis showed that the effects are more harmful in the presence of damp, under the action of loading tested, but despite this, the fracture was well defined starting in the external parts and spreading to the internal regions when one when it reaches the hybrid load

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The flowering is a physiological process that it is vital for plants. This physiological process has been well studied in the plant model Arabidopsis, but in sugarcane this process is not well known. The transition of the shoot apical meristem from vegetative to flowering is a critical factor for plant development. At Brazil northeastern region, the transition to flowering in sugarcane has an important effect as it may reduce up to 60% its production. This is a consequence of the sugar translocation from stalks to the shoot apical meristem which is necessary during the flowering process. Therefore, the aim of this work was to explore and analyze cDNAs previously identified using subtractive cDNA libraries. The results showed that these cDNAs showed differential expression profile in varieties of sugarcane (early x late flowering). The in silico analysis suggested that these cDNAs had homology to calmodulin, NAC transcription factor and phosphatidylinositol, a SEC14, which were described in the literature as having a role in the process of floral development. To better understand the role of the cDNA homologous to calmodulin, tobacco plants were transformed with overexpression cassettes in sense and antissense orientation. Plants overexpressing the cassette in sense orientation did not flowered, while plants overexpressing the cassette in the antissense orientation produced flowers. The data obtained in this study suggested the possible role from CAM sequence, SEC14 and NAC in the induction/floral development pathway in sugarcane, this is the first study in order to analyze these genes in the sugarcane flowering process.

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This work demonstrates the importance of using tools used in geographic information systems (GIS) and spatial data analysis (SDA) for the study of infectious diseases. Analysis methods were used to describe more fully the spatial distribution of a particular disease by incorporating the geographical element in the analysis. In Chapter 1, we report the historical evolution of these techniques in the field of human health and use Hansen s disease (leprosy) in Rio Grande do Norte as an example. In Chapter 2, we introduced a few basic theoretical concepts on the methodology and classified the types of spatial data commonly treated. Chapters 3 and 4 defined and demonstrated the use of the two most important techniques for analysis of health data, which are data point processes and data area. We modelled the case distribution of Hansen s disease in the city of Mossoró - RN. In the analysis, we used R scripts and made available routines and analitical procedures developed by the author. This approach can be easily used by researchers in several areas. As practical results, major risk areas in Mossoró leprosy were detected, and its association with the socioeconomic profile of the population at risk was found. Moreover, it is clearly shown that his approach could be of great help to be used continuously in data analysis and processing, allowing the development of new strategies to work might increase the use of such techniques in data analysis in health care

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The lipid profile is a group of lab tests that include triglycerides, total cholesterol (TC), high-density lipoprotein cholesterol (HDL-C) and low-density lipoprotein cholesterol (LDL-C). However, serum non-HDL-C, Apo A-I and Apo B levels, as well as the lipids ratios (TC/HDL-C, LDL-C/HDL-C and Apo B/Apo A-I), have been described as better predictors of cardiovascular diseases. Reference intervals are tools often used to help the evaluation of the people s health state. These days, Brazilian studies still use the reference intervals of lipids and lipoproteins from other countries, ignoring differences between the populations. Therefore, this study aimed to establish reference intervals for lipids, lipoproteins and apolipoproteins in adults of Rio Grande do Norte/Brazil. Healthy individuals (96 men and 283 women) between 18 and 59years old formed the reference sample group. The samples were collected after fasting 12 to 14 hours. Information on lifestyle and dietary habits of the participants were obtained through questionnaire. The serum glucose level and renal and liver activity were evaluated by laboratory testing. The results of lipid profile were analyzed according to sex, age and mesoregion of Rio Grande do Norte, with significance level of 5% (p < 0,05). The lower and upper reference limits were identified by the 2.5 percentile and 97.5 percentile, respectively, and assurance intervals of 90% was calculated for each of these limits. Among the determinants of lipid profile analyzed, only a few significant differences were observed according to sex, but in terms of age, the groups of smaller and older ages were most likely different. When evaluated by region, the means of West region shown the most significant variations. Not many studies were useful to compare the reference intervals determined in this study. Thus, it becomes necessary to carry out similar studies in other regions of Brazil and of the world given the clinical importance of reference intervals

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The following text addresses the magical-religious experience carried on by many individuals when they seek to solve their love, financial and health problems by means of white magic spells done by pais-de-santo e mães-de-santo (saint s father and saint s mother) from umbanda. The rites through which this seek can be detected are free love spells, troublesolving spells, and healing spell. The concept of experience, here understood as the thing which gives sense to the sense, has been the main guiding idea of the reflections here enclosed. People who seek the umbandista spells as a way of solving their daily afflictions have the opportunity of living a rich magical-religious experience in which several dimensions intersect. Among these dimensions I decided to study the performance, the knowhow and the subjetivity. Each one gave rise to the opportunity of studying a range of other themes, such as the corporeity, the gestuality, vocality, the world knowledge, the science, the secret, the emotions and the moral. The ethnographic research was carried on in the yards which are named after Dona Luiza, Pai Gledson, Pai Salviano and Dona Terezinha umbanda, all of them situated in the town of Limoeiro do Norte, Ceará

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This paper presents a research realized with Physics, Chemistry and Biology teachers, and it aimed to evaluate: 1) the development level of those teachers regarding the abilities that make possible to teach high school students about how to measure in practical and experimental work; 2) the formatives necessities regarding those abilities; and 3) the order of priority for teacher´s formation regarding those abilities. The study is based on the activity theory, from A. N. Leontiev (1983), since we considerer the teacher´s formation a kind of activity for which the category necessity is source of motivation and in which is a necessary condition for professionality and for the professional development. A questionnaire with open and closed questions was applied to 116 teachers during three pedagogic workshops realized to dynamize the science laboratory. The instrument allowed us to obtain the personal and professional profile of the participants, as well as their development level, their formative necessities and their order of priority about the teaching of the abilities related to the work of testing measuring hypothesis, regarding: a) to operationalize variables of a hypothesis in experimental work; b) to measure in practical and experimental work; c) to estimate possible measuring mistakes and use proper procedures to minimize them; d) to estimate the validity of a measuring; and e) to estimate the confiability of a measuring. The research results indicated some limitations of the teachers about their development level in all the analyzed abilities. More than 90% of the teachers considered those deficiencies as necessities of the continuing formation. Most of them (about 54%) expressed immediate priority for formation in each one of the abilities. From a correlation, using the statistic chi-square test, between the development level and the formative necessities for the five abilities, the obtained results allow us to assure that, for all those teaching abilities, there is a strong correlation between the development level and the formative necessity. This situation is symptomatic of the importance of approaching more the science teaching and the teacher´s formation on practical and experimental work in high school as key-component of scientific education in basic education. The obtained results can contribute, as subsidy, for continuing formation courses, having as base the necessities that constitute motivation elements of the teachers for professional development

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This research aims to investigate the evolution presented during three decades (1980, 1990 and 2000) of using the tools of Operations Research (OR) as a suport to decision making in Production Operation Management (POM). Hypothesis tests were made to verify the proportional growth of a given area over the decades to the detriment of the areas of facility layout, capacity planning, production scheduling and inventory management. Six journals were selected and from them more than 800 articles were used for classification and analysis in the grounds of review. It also discussed possible ways for future research and comparisons are made with other papers of literature review. As a result, it was found that areas of heuristics and simulation showed a greater quantity of contributions in all POM areas of this study

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The number of applications based on embedded systems grows significantly every year, even with the fact that embedded systems have restrictions, and simple processing units, the performance of these has improved every day. However the complexity of applications also increase, a better performance will always be necessary. So even such advances, there are cases, which an embedded system with a single unit of processing is not sufficient to achieve the information processing in real time. To improve the performance of these systems, an implementation with parallel processing can be used in more complex applications that require high performance. The idea is to move beyond applications that already use embedded systems, exploring the use of a set of units processing working together to implement an intelligent algorithm. The number of existing works in the areas of parallel processing, systems intelligent and embedded systems is wide. However works that link these three areas to solve any problem are reduced. In this context, this work aimed to use tools available for FPGA architectures, to develop a platform with multiple processors to use in pattern classification with artificial neural networks