79 resultados para hollow


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In this paper, natural frequencies were analyzed (axial, torsional and flexural) and frequency response of a vertical rotor with a hard disk at the edge through the classical modal and complex analysis. The equation that rules the movement was obtained through the Lagrangian formulation. The model considered the effects of bending, torsion and axial deformation of the shaft, besides the gravitational and gyroscopic effects. The finite element method was used to discretize the structure into hollow cylindrical elements with 12 degrees of freedom. Mass, stiffness and gyroscopic matrices were explained consistently. The classical modal analysis, usually applied to stationary structures, does not consider an important characteristic of rotating machinery which are the methods of forward and backward whirl. Initially, through the traditional modal analysis, axial and torsional natural frequencies were obtained in a static shaft, since they do not suffer the influence of gyroscopic effects. Later research was performed by complex modal analysis. This type of tool, based on the use of complex coordinates to describe the dynamic behavior of rotating shaft, allows the decomposition of the system in two submodes, backward and forward. Thus, it is possible to clearly visualize that the orbit and direction of the precessional motion around the line of the rotating shaft is not deformed. A finite element program was developed using MATLAB (TM) and numerical simulations were performed to validate this model. Natural frequencies and directional frequency forced response (dFRF) were obtained using the complex modal analysis for a simple vertical rotor and also for a typical drill string used in the construction of oil wells.

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The common vampire bat Desmodus rotundus has as main food source blood of medium and large sizes mammals, but sporadically is observed feeding on birds, causing occasionally excessive bleeding and economic losses. Due to this D. rotundus is one of the most studied species of bats in the Americas. Once known that the lunar clarity might influence the nocturnal activities of the common vampire bats, the present study was carried out to know the behavior and schedules of emergencies and returns of bats to the shelter, its social behavior at the shelter´s entrance, especially of the dominant male, and the size and composition of the colony in different moon phases. The colony was composed by 105 individuals (65 females and 40 males) harboring in a hollow-tree of Farm Edgardia in Botucatu Municipality, State of São Paulo. Through the eight filming sessions, two for each moon phase, it was possible to observe that the distribution of emergences and returns to the shelter thought the night followed a specific pattern for each moon phase. The greatest number of emerging bats occurred in periods in which the moon was not born yet and the largest number of returns just before moon has been reached its maximum level in the sky. Therefore, the time period that bats are staying outside the shelter seems to be directly influenced by lunar light. This factor can influence the social activity of the colony and, in particular, the dominant male, who remains still on tree’s trunk, near the entrance of the shelter with greater frequency during periods of low moon light

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The aim of this work was the development a computer code for simulation and analysis of atomic spectra from databases constructed from the literature. There were created four routines that can be useful for spectroscopic studies in the atomic processes of laser isotope separation. In the first routine, Possible Transitions, the program checks the possible electron transitions from an energy level of the atom present in the database considering the selection rules for an electric dipole transition. The second routine, Locator Transitions, checks the possible electronic transitions within a user-specified spectral region. The routine Spectra Simulator creates simulated spectra using the graphical application gnuplot through lorentzian curve and finally, the routine Electronic Temperature determines the temperature of electronic excitation of the atom, thought the Boltzmann Plot Method. To test the reliability of the program there were obtained experimental emission spectra of a hollow cathode discharge of dysprosium and argon as a buffer gas. The hollow cathode discharge has been subjected to different values of operating currents and pressure of inert gas. The spectra obtained were treated with the assistance of program routines developed (Transition Locator and Spectra Simulator) and temperatures electronic excitation of the atoms of dysprosium in the different discharge conditions were calculated (routine Electronic Temperature). The results showed that the electronic excitation temperature of the neutral dysprosium atoms in the hollow cathode discharge increases with increasing current applied to the cathode and also by increasing the gas pressure buffer. The determination coefficients, R2, obtained by the Electronic Temperature routine using the linear adjust of the Boltzmann Plot Method were greater... (Complete abstract click electronic access below)

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In hospitals, health professionals may face different situations and problems. By following them, it is remarkable that one of the difficulties is related to the support provided by the facilities to carry out their work. This also affects the quality of treatment offered to patients. One of the points of improvement that could be studied is hospital beds. The Fawler's simplest hospital bed type, used in most Brazilian public hospitals, is designed with an ergonomic average height that offers a default position for analysis and treatment of patients. There is no possibility of adjusting the height of those beds, and hence there is a limitation in this regard since that height is fixed, but the physical structures of the workers and patients may vary widely and there may be a conflict when there are people too large or small involved in this process. Beyond that, studies by experts show that beds with height adjustment decreases the muscular effort and improve the movement quality of the spine of nursing staff, reducing the force on certain vertebrae and also the ergonomic risk. Of course, patient comfort is also affected accordingly. As the beds made with height adjustment are very expensive, this study aims to design a device to adapt the not adjustable beds. The project must be viable from an economic and mechanic standpoint, being able to adapt both old and new simplest Fawler hospital bed models, since their dimensions are similar. The final result shows that it is possible to adapt such beds using the designed concept at a viable cost. Furthermore, this concept could be applied in other bed types or objects that have hollow feet

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From a diagnostic on the learning of written text, this research aimed to carry out educational activities aimed at textual production, performing operation and activity of reflection on texts written by students in a learning situation of parallel recovery, aiming to improve the standard textuality of his written production. These actions were guided from the conception of language as social practice and discourse and, later, a survey was made in the standard of textuality textual productions resulting from such actions. 5 students participated in the research of a 4th grade of elementary school, a School of Duartina peripheral zone integrating the local school system of that city. The textual productions written by these students were analyzed from three categories: common mistakes in the process of literacy, with subdivisions: phonetic transcription, dialetação, hollow hipossegmentação or vocabulary, or improper separation hiperssegmentação, overcorrection, exchange, omission or addition letters, phonemes homorganic exchange; factors textual and contextual, in which it reviewed the following factors: coherence, cohesion and story elements, clarity, in which category were analyzed: the segmentation of text into paragraphs, grammar errors of different nature, use of direct and indirect speech. The results of the intervention and ongoing analysis of data shows that there has been considered developments in the performance of the written production of the research subjects

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This paper analyzes unconventional segmentation of word found in texts of the sixth grade of Elementary School. Through quantitative and qualitative analysis, we describe the prosodic characteristics that may be motivated the hyper and hippossegmentation of words found in 27,4% of 606 investigated texts. We identified a tendency toward a more text with hippossegmentation than hypersegmentation, characteristic similar to what is reported about children’s text. Taking into account the theoretical framework of Prosodic Phonology, we argue about the relevance of prosodic word and clitic group in the description of the regularities observed in data of unconventional segmentation of word. We note that (i) in cases of hipposegmentation, it predominates the hollow of a clitic followed by a phonological word, (ii) in cases of hypersegmentation, it predominates a segmentation of a prosodic word into a clitic group. We present evidences to be the spelling of clitic elements a challenge to students analyzed. By investigating in the grammatical class that owned the clitics spelled unconventionally, we verified that they are prepositions (“em, de, com”) and pronouns (“me, lhe, lo”), a characteristic that particularize these data in relation to data from students in the early stage of language acquisition.

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Pós-graduação em Engenharia Civil - FEIS

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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

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Pós-graduação em Ciência Animal - FMVA

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Pós-graduação em Ciência dos Materiais - FEIS

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Premise of research.The highly specialized grass inflorescence varies with respect to phyllotaxis, with the reproductive meristem forming primary lateral branches that are either spirally arranged or distichous. The Brazilian bamboo Eremitis is highly unusual in that it has a dimorphic inflorescence, typically composed of an apical gynecandrous whorl of both male and female spikelets and basal whorls of male spikelets. Although not closely related to them, Eremitis shares some structural similarities with some early-divergent grasses.Methodology.We use SEM and LM to describe the development of the reproductive structures of Eremitis to clarify our understanding of the highly specialized grass inflorescence and flower.Pivotal results.Developmental studies show that the inflorescence of Eremitis is actually partially whorled and partially distichous. The apical whorl is abortive. The female spikelet is not terminal on the axis, in contrast with the majority of grasses. All the male spikelets are distichously attached to the inflorescence axis and separated into groups. There is a hollow style with two vascular bundles.Conclusions.The strong morphological similarities between Eremitis and some early-divergent grasses are here supplemented by several anatomical similarities, perhaps due to a shared pollination syndrome.

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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

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The technique proposed aims at reducing the weight of individualized ample ocular prostheses using acrylic resins as well as simplifying laboratory procedure. For that, prefabricated hollow spheres made of plastic material, were inserted in the sclera. The average weights of the solid conventional sclera (5.30g) and those of the respective prefabricated plastic ones (3.91g) were compared. The weight reduction was significative with a confidence interval of 95% by the Student t test. ln addition, for illustration purpose, the technique was applied to patients in the ward of the Maxillofacial Prostheses Dicipline of the Dentistry School in the Campus of São José dos Campos - UNESP, having each patient received a solid prosthesis and a hollow prefabricated one made of plastic material. It has been concluded that the prostheses material spheres were inserted are lighter than the ones which received solid spheres; furthermore, thr technique is viable for ample anophtalmic cavities and requires few sessions