Complex modal analysis of a slender vertical rotor by finite elements method

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.

A indução da potencialização pós-ativação através dos saltos: pliométrico e vertical

The Post-Activation Potentiation (PAP) offers a proposal to optimize the production of strength and muscular power when performing exercises near maximum to actions previously assessed . The present study aims to show the activation process of postactivation potentiation (PAP) through vertical and plyometric jumps, and explain the user function of these movements. The ratio of post-activation potentiation resulting from plyometric and vertical jumps and explosive strength in the lower limbs aims to improve the potency and maximal strength, proven through studies and protocols detailed here. The results of this research come can be applied both for athletes and for individuals with experience in strength training and jumps (sports like volleyball, basketball and handball). The study was conducted through a literature review, conducted in scientific journals indexed in major databases (PubMed, ISI-Web of Science, SCIELO), books and academic papers (theses and dissertations)

Análise cinemática e cinética do salto vertical de crianças com transtorno do desenvolvimento da coordenação (TDC)

Due to motor difficulties, children with developmental coordination disorder (DCD) doesn't feel motivated to do physical activities, sometimes resulting in a decline of their physical fitness, but it isn't really known for sure the reasons that induct children with DCD to low performances in physical fitness tests, because a lot of tasks that are part of the battery of tests of physical performance are complex in the coordination and/or motor control point of view, like the vertical jump for example. Therefore, the objective of this study was to investigate the factors that induct children with DCD to low performances in physical fitness tests, especially in the vertical jump task. For that, cinematic (duration of the eccentrical phase, duration of the concentrical phase, shift of the mass center and velocity of the mass center), kinetic (potency peak and force peak) and vertical jump performance analysis in two conditions (with the use of arms and without it) were realized in a force platform. The results indicated that children with DCD show a lower performance compared to their peers with typical development (TD), due to a lower potency production

Vila Vertical: moradia estudantil

Este trabalho visa explorar o tema da sustentabilidade, procurando levantar os conceitos e ideais implicítos neste termo, que muitas vezes é disseminado de modo vago e impreciso, o que leva, consequentemente, à banalização do termo, e a perda do sentido real da palavra. É feita a análise e crítica daquilo que é rotulado, ou se auto intitula como sustentável, levando em consideração os padrões estabelecidos por órgãos regulamentadores responsáveis por conceder certificações de caráter sustentável (como por exemplo o Green Building Council e a Fundação Vanzolini) e os conceitos estabelecidos por autores que também exploram o tema. Com base nisso é feita a leitura de alguns projetos que atuam em diversas vertentes, mas que porém, têm como base o mesmo objetido. Assim são analisadas as soluções apresentadas, e os aspectos que fazem daqueles projetos relevantes para a busca da sustentabilidade. Através da junção e da reflexão de todas as informações coletadas, foi gerado o conceito e as diretrizes que servirão de base para o desenvolvimento do projeto, desde a escolha da área a ser trabalhada, ao programa de necessidades e à volumetria das edificações

As possíveis relações entre desenvolvimento moral e uso de crack por adolescentes

The dependency of psychoactive substances whether licit or illicit, among adolescents is a topic that has aroused much discussion today. One of the psychoactive substance that has caught the attention of authorities and experts, its potential dependence, increasing the number of addicts and speed with which triggers the human degeneration is the crack (a derivative of cocaine - Erythroxylon coca), used via the smoked administration. Understanding the phenomenon of increasing their use requires an analysis of the concepts of addiction throughout history, current research encompassing scientific findings in epidemiology and statistics involving several types of pharmacological substances, and especially the analysis of data related specifically to crack the focus of our theme. In order to contribute to ongoing discussions and offer possible alternatives for effective intervention, especially in schools, we conducted a survey that sought to find evidence of a possible relationship between crack use and moral reasoning. Since our work specifically theoretical nature, we use to reach our goals, assumptions, two researchers in the concept of human morality: Jean Piaget (1994) and Lawrence Kohlberg (1992) both traveling within the proposed cognitive-evolutionary human development. For an understanding of the proposals of these two researchers, we use research to (Lepre, 2005), as guiding thesis of this work. The results presented indicate that adolescents who use crack are very close to a level of moral reasoning pre-conventional and conventional, although it is important to state that more accurate results require further research on the subject, including those involving field research. Yet we can conclude that prevention must go through a dialogue that privileges the moral education as possible means of effective intervention against the use of crack, allowing the construction of autonomy... (Complete abstract click electronic access below)

Reestruturação recente da indústria petroquímica: análise Brasil-Mundo do processo de integração vertical

Este estudo analisa o desenvolvimento do processo de integração vertical na indústria petroquímica brasileira a partir da década de 90, focando nos determinantes para este movimento e confrontando com o mesmo processo adotado em grandes empresas mundiais da indústria

Fatores prognósticos para o abandono precoce do tratamento da dependência do álcool, crack e outras drogas em uma comunidade terapêutica

Pós-graduação em Saúde Coletiva - FMB

Caracterização do fator de intensidade de tensão em corpos trincados através do método dos elementos finitos

The industry generally has sought materials with high mechanical resistance, low density, thermal stability and corrosion resistance. In the aerospace industry, for example, the use of aluminum alloys, such as Al 2024-T351 and Al 7075-T7351, have become essential. However, the use of these materials often do not resulted in a satisfactory performance of the component, since the presence of cracks can cause total rupture of the component, even with a tension below the yield stress of the material, unexpectedly. In this work, these aluminum alloys were analyzed and samples were modeled by the finite element method. Moreover, in the models were applied two different types of cracks, central and edge crack, a vertical force was applied to result in a tension 70% of the yield stress of the material analyzed. Through stress asymptotic distribution in the region near the crack tip were calculated the values of the stress intensity factors for each crack length, after the stress intensity factors characterized were compared graphically with the values of fracture toughness found in the available literature

Incomplete vertical root fracture associated with lateral compaction technique: a microscopic analysis

Objective: This study evaluated the effects of root canal obturation employing lateral compaction technique and spreader load of 1.5 kg on the incidence of complete (CVRF) or incomplete vertical root fractures (IVRF). Material and Methods: Twenty-seven distal roots of extracted human mandibular molars were used. All root canals were prepared by biomechanical step-back technique and obturated by lateral compaction technique. The prepared roots were distributed into two groups: G1- experimental (n = 17) and G2- control (n = 10). During obturation, load of 1.5 kg was applied to a size # 30 finger spreader. Pre- and post-obturation images of the coronal portion of the roots were captured by inverted digital microscopy and analyzed by one trained examiner. Data were evaluated by Fisher’s test (p < 0.05) using GrapH Pad Prism 5.0. Results: No roots exhibited CVRF. All fractures observed before and after obturation were IVRF or “other defects”. In G2 (control group), there was no increase of IVRF number. Interestingly, G1 presented an increase in the IVRF number to 70.59% in the 12 teeth out of 17 teeth studied. The statistical analysis showed that the mean of IVRF increased significantly in G1 when compared to G2 (p < 0.05). Conclusion: The application of a 1.5 kg spreader load during lateral compaction technique does not produce complete vertical root fractures, but may produce incomplete fractures or “other defects”.

Estimação de parâmetros de linhas de transmissão utilizando técnicas de decomposição modal: Aplicação em linhas com plano de simetria vertical

Pós-graduação em Engenharia Elétrica - FEIS

Dinâmica não linear e projeto de controle em sistemas de transporte vertical: comportamentos periódicos e caóticos

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Filling of simulated lateral canals with gutta-percha or thermoplastic polymer by warm vertical compaction

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

Vertical variation in autumn leaf phenology of Fagus sylvatica L. in southern Germany

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Regeneração óssea vertical usando barreira não-porosa de politetrafluoretileno em implantes osteointegrados inseridos parcialmente na tíbia de coelhos

The purpose of this study was to evaluate the possibility to obtaining guided bone regeneration utilizing a nonporous PTFE barrier in the osseointegrated implants, protruding from the bone level of the rabbit tíbia. The histologic characteristics of the interface between titanium implants, one group titanium-plasma coated, another group with acid-treated surfaces and the regenerated bone were also studied Twenty Screw-Vent implants were placed in tibias of five rabbits, two at the right side and two at the left side, protruding 3 mm from the bone level, to create a horizontal bone defect. ln the experimental side, the implants and adjacent bone were protected with a nonporous PTFE barrier. Histologic analysis after three months showed that all implants were in direct contact with the bane. Histologic measurements showed an average gain in bone height of the 2.15 and 2.42 mm for the barrier group and 1.95 and 0.43 mm for the control defects, in the titanium plasma-spray and acid-treated implant surfaces, respectively. The results suggest that the placement of implants protruding 3 mm from crestal bone defects may result in vertical bone augmentation and the regenerated bone is able to osseointegrate implants. lt seems to be critical the use of the PTFE barrier when acid-treated surface implants are inserted