Avaliação da fissuração por fadiga em tubos durante transporte marítimo

Tubos de aço são transportados diariamente em todo o mundo, por caminhão, trem ou navio. Conseqüentemente, danos de transporte, podem ocorrer com freqüência e regularidade. O tipo de dano particular selecionado para este estudo foi o de trinca por fadiga, o qual é considerado como um dos mais críticos. Neste trabalho foram estudados tubos de aço fabricados de acordo com os requisitos da norma API 5L [1]. Foram efetuadas caracterizações químicas, mecânicas e metalográficas de um tubo com diâmetro 609,6 mm e espessura 15,87 mm grau X-65. A simulação do transporte por navio de tubos de aço foi feita submetendo-se seções de tubo com comprimento igual a 0,1 metro, a ciclos de fadiga por meio de máquina servo-hidráulica. Foi possível concluir que em tubos soldados, a região adjacente ao cordão de solda é a mais crítica, e que quando o posicionamento do tubo na carga é efetuado de maneira que a solda fique apoiada sobre alguma superfície rígida, a ocorrência de trinca por fadiga torna-se possível principalmente se os procedimentos de manuseio, carregamento e transporte não forem executados da maneira como recomendada pelos fabricantes de tubos e pela norma API [2].

Evaluation of fatigue behavior on repaired carbon fiber/epoxy composites

The continuous use of structural polymer composites in aeronautical industry has required the development of repairing techniques of damages found in different types of laminates. The most usually adopted procedure to investigate the repair of composite laminates has been by repairing damages simulated in laminated composite specimens. This work shows the influence of structural repair technique on mechanical properties of a typical carbon fiber/epoxy laminate used in aerospace industry. When analyzed by tensile test, the laminates with and without repair present tensile strength values of 670 and 892 MPa, respectively, and tensile modulus of 53.0 and 67.2 GPa, respectively. By this result, it is possible to observe a decrease of the measured mechanical properties of the repaired composites. When submitted to fatigue test, it is observed that in loads higher than 250 MPa, this laminate presents a low life cycle (lower than 400,000 cycles). The fatigue performance of both laminates is comparable, but the non-repaired laminate presented higher tensile and fatigue resistance when compared with the repaired laminate.

The surface treatment influence on the fatigue crack propagation of Al 7050-T7451 alloy

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

Assessment of cumulative damage by using ultrasonic C-scan on carbon fiber/epoxy composites under thermal cycling

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

Investigação do funcionamento cognitivo de pacientes pediátricos diagnosticados com leucemia linfóide aguda - LLA

The present work investigated the cognitive operation of children diagnosed with acute lymphoblastic leukaemia (ALL), accompanied at pediatric oncologic institutions at the city of Natal/RN. Had participated in this study twenty children, of both sexes, between six and twelve years old, with the ALL diagnostic, who were in treatment (n=10) and out of treatment for at least one year (n=10) and were submitted exclusively to chemotherapy as CNS prophylaxis. The utilized protocol of neuropsychological evaluation covered the following cognitive abilities: intellective capability, attentional and memory systems, and executive functions. Data was analyzed through descriptive and inferential measures, with the support of the Mann-Whitney U Test and T-test, considering the influence of the variables sex, age at diagnostic and the past time since the beginning of the treatment over children s performance. The intellective capability evaluation showed low score to the out-of-treatment groups, female and children under five years old to the diagnostic. In concern of attentional systems, groups showed the expected performance. In a relevant way, in the evaluation of executive functions, were found reduced scores within all groups, especially inside the in-treatment group. Memory evaluation pointed to reduced performance in items concerning to learning evolution and spontaneous evocation after interference to the several groups. It can be concluded, reffer to the occurrence of transitory and permanent impact associated to the intrusion of chemotherapic components during the maturational course of the CNS. It s expected that the present investigation and the development of similar studies enable major comprehension about the mode, extension and repercussion of these damages subsidizing the development of strategies which may minimize them and provide better xxiii life quality to this clinical subgroup

Optimal Frequency Range Selection for PZT Transducers in Impedance-Based SHM Systems

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Non-destructive evaluation tool for monitoring and detection of structural damage by using neural network.

This work studies the capability of generalization of Neural Network using vibration based measurement data aiming at operating condition and health monitoring of mechanical systems. The procedure uses the backpropagation algorithm to classify the input patters of a system with different stiffness ratios. It has been investigated a large set of input data, containing various stiffness ratios as well as a reduced set containing only the extreme ones in order to study generalizing capability of the network. This allows to definition of Neural Networks capable to use a reduced set of data during the training phase. Once it is successfully trained, it could identify intermediate failure condition. Several conditions and intensities of damages have been studied by using numerical data. The Neural Network demonstrated a good capacity of generalization for all case. Finally, the proposal was tested with experimental data.

Adaptive filter feature identification for structural health monitoring in an aeronautical panel

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Structural Health Monitoring in Smart Structures Through Time Series Analysis

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

Estabilidade de agregados de um latossolo vermelho degradado em recuperação com adubos verdes, calcário e gesso

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

Atividade biológica de células-tronco da polpa de dentes decíduos humanos submetidas à criopreservação

Dental pulp stem cells have been widely investigated because of their ability to differentiate into both dental and non-dental cells, with potential use in therapies involving tissue engineering. The technique of cell cryopreservation represents a viable alternative for the conservation of these cells, since it stops reversibly, in a controlled manner, all of cell biological functions in an ultra low temperature. The present study aimed to evaluate, using in vitro experiments, the influence of a cryopreservation protocol on the biologic acti vity of stem cells from human exfoliated deciduous teeth (SHED). Cells obtained from the pulp of three deciduous teeth on end-stage exfoliation or with indicated extraction were expanded in α-MEM culture medium supplemented with antibiotics and 15% fetal bovine serum. At second subculture (P2), a group of cells were submitted to cryopreservation for 30 days in 10% DMSO diluted in fetal bovine serum, at -80º C, while the remind cells continued under normal conditions of cell culture. Cell proliferation was evaluated in both groups (not cryopreserved or cryopreserved) by Trypan blue stain essay at intervals of 24, 48 and 72h after plating. Cell cycle analysis of SHEDs submitted or not to the cryopreservation protocol was performed in the same intervals. Events related to cell death were studied by Annexyn V and PI expression under flow cytometry at the intervals of 24 and 72h. The presence of nuclear morphological changes was evaluated by DAPI staining at 72h interval. It was observed that both groups exhibited an upward cell proliferation curve, without considerable changes in cell viability throughout the experiment. The distribution of cell in the cell cycle phasis was consistent with cell proliferation in both groups. There were no nuclear morphological damages in the end range of the experiment. therefore, it is concluded that the proposed cryopreservation protocol is efficient for storing the studied cell type, allowing its use in future experimental studies

Preferência de oviposição de Grapholita molesta (busck) (lepidoptera: tortricidae) em cultivares de pessegueiro

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

Saúde do trabalhador: entre os dispositivos legais e as práticas efetivas

The health worker is seized in this research beyond the mere applicability of legal devices concerning the legislation of Labor, in order to be established correlations with activities alluding to the public power in the ambit of State of Rio Grande do Norte (RN). This dissertation is an cutting of analysis circumscribed in the research, "Accidents at work: law, citizenship and justice," of the Grupo de Estudos Seguridade Social e Trabalho (GESTO) of Universidade Federal do Rio Grande do Norte (UFRN). The overall goal turned to apprehend and relate contradictory elements inherent compliance of Occupational Health and Safety (OHS) in the supermarket which showed the highest occurrence of legal violations recognized by the Labor Justice of RN in the period between 2006 and 2008 . The specific objectives turned to identify, from the condemnatory sentences, violations inherent in the protective direction of the OH & S legislation; analyze the relationship of health damages to workers at the supposed recognition of rights claimed in condemnatory sentences and correlate violations inherent in the legislation OSH impacts on the health of workers, from data contained in expert reports. The justification for perform the research backed up, among other factors, in the fact that class of activity has been presented as the most recurrent in condemnatory sentences, since it chose to focus the analysis on documentary evidence from the supermarket which showed greater expression in relation to violations of the OSH legislation. From a qualitative perspective, the methodological approach was based on content analysis of thirteen condemnatory sentences, handed down by the potiguar labor justice, and three expert reports from a large supermarket in the city of Natal/RN. Aftermaths are evidenced relating to the cyclical processes of reorganization of capital, demanding requirements for labor organizations whose strategies for survival include identifying mechanisms to extract as much of the work force. Structural determination and ideological context that puts into question the historical achievements of workers, for example the legal devices aimed at preventing workplace accidents, expressed in this research as relativized, showing limitations of reach, as was inferred the indemnities, by material and moral damages, arising from Work-Related Musculoskeletal Diseases (MSDs'S), recognized by the laborite judiciary

(In)visibilidade da violência doméstica no atendimento do Sistema Público de Saúde: nos bairros das Quintas e de Felipe Camarão

It analyses the approach given by health professionals (social workers, nurses and doctors) against woman violence at the Medical Unities of Felipe Camarão and Quintas of the City of Natal and searches to identify if the domestic violence is (in)visible at the Public Health Assistance System attendance. and It refers to the grandiosity of this violence and its consequences to the women health, recognizing it as a public health problem. To the comprehension of the relationship between violent acts against women and their health serious damages, exposes the battle history of the feminist movements and the brazilian women, demonstrating the visibility acquired by theses conquests of the questions related to the women and how the gender study becomes the central category to (re) think the social relations involving women and men, specially, the violent relationships between them. It analyses, mainly, those practiced by the husbands, partners, boyfriends or lovers. It refers, at the end, about the public politics of violence combat adopted at police stations at health centers, showing the difficulties to establish the legislation that exists to combat the violence suffered by the women that look for assistance at the health unities. It intends, with this way, to give more visibility to the domestic questions at the marital relations and ask attention from the public power and health professionals between them, the social worker to the (in) visibility of this problems at the attendances practiced

Estudo de alterações na cavidade oral em pacientes com doença do refluxo gastroesofágico

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)