Investigation of Bulk and DTMOS triple-gate devices under 60 MeV proton irradiation

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Electrical conductivity of Ag-Na ion exchanged soda-lime glass

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

On the Performance of a Two-Stage Vibration Isolation System Which has Geometrically Nonlinear Stiffness

Linear single-stage vibration isolation systems have a limitation on their performance, which can be overcome passively by using linear two-stage isolations systems. It has been demonstrated by several researchers that linear single-stage isolation systems can be improved upon by using nonlinear stiffness elements, especially for low-frequency vibrations. In this paper, an investigation is conducted into whether the same improvements can be made to a linear two-stage isolation system using the same methodology for both force and base excitation. The benefits of incorporating geometric stiffness nonlinearity in both upper and lower stages are studied. It is found that there are beneficial effects of using nonlinearity in the stiffness in both stages for both types of excitation. Further, it is found that this nonlinearity causes the transmissibility at the lower resonance frequency to bend to the right, but the transmissibility at the higher resonance frequency is not affected in the same way. Generally, it is found that a nonlinear two-stage system has superior isolation performance compared to that of a linear two-stage isolator.

Increased Expression of Angiotensin II Type 2 Receptors in the Solitary-Vagal Complex Blunts Renovascular Hypertension

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Variação inter-sexual na frequência de cromossomos Bs em Corydoras aeneus (Siluriformes: Callichthyidae)

The genus Corydoras, the highest among the Siluriformes, Callichthyidae is owned by the family, consisting of 177 valid species and widely distributed in cis-Andean portion of South America How striking feature has two longitudinal series of dermal plates covering almost the entire body. Cytogenetic studies in Callichthyidae show many chromosomal rearrangements, including events of polyploidy in their evolutionary history, particularly the genus Corydoras, in which the variation is the diploid number of 2n = 40 to 2n = 134 chromosomes. The absence of information on the frequency of chromosomes in the group Bs motivated this work with the species Corydoras aeneus. A population from the Tietê River basin in Ribeirão Claro (subbasin Corumbataí - Rio Claro, SP) was sampled a total of 20 subjects (10 males and 10 females) and 30 metaphases per individual were analyzed cytogenetically. Were carried out by impregnation techniques silver (Ag-NOR). The observed modal diploid number was 2n = 60 (26m +26 sm +8 st), with the variable occurrence of 1 or 2 Bs chromosomes in males and a B chromosome in females, both acrocentric. Regarding the variation in the frequency of chromosome Bs, the occurrence of two B chromosomes is directly linked to males, because there were no female sampled with the occurrence of two chromosomes Bs The low frequency of Bs in females suggests that this event can be sporadic this sex, different from males in which this appears to be set supernumerary chromosome showing a higher frequency of 2 Bs than the actual modal number of 2n = 60. Further studies will be performed to understand the dynamics of the B chromosome in the population

Análise do comportamento em fadiga de rodas ferroviárias fabricadas pelos processos de forjamento e fundição

Since the beginning of the railway industry until today, rail wheels are important components to the good working of a railway. For being a critical security item, design and maintenance are done with extremely care to avoid failures. Despite de fact of railway components be projected to support a big number of cyclic solicitation during its life, some accidents still occur. These accidents, despite the low frequency, always have great consequences, drawing in great financial, material, and people losses. Nowadays, railway component failure is relatively low, because it’s been projected to work below the materials Fatigue Resistance Limit, however, with the growing demand of faster trains and higher load for each axle, the occurrence probability is even bigger. This work includes a comparative study of two fabrication processes (casting and forging) applied in the production of rail wheels where it was measured the mechanical properties of traction and fatigue. The study also verified through microstructural analysis, hardness, traction and fatigue tests, statistical analysis of fatigue test results and fractographic analysis that forging process lead to better correlations between fatigue life and mechanical properties, providing more security in railroads, less wagon retention caused by corrective maintenance and smaller operational cost with its use

Desenvolvimento de um simulador virtual de vazamento para testar correlacionadores acústicos comerciais

Pós-graduação em Engenharia Mecânica - FEIS

Projeto de controladores para a maximização de sistemas de captação de energia considerando excitação não ideal

Pós-graduação em Engenharia Mecânica - FEIS

Maternal protein restriction increases respiratory and sympathetic activities and sensitizes peripheral chemoreflex in male rat offspring

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Immediate and long-term effects of psychological stress during adolescence in cardiovascular function: comparison of homotypic vs heterotypic stress regimens

Adolescence has been proposed as an ontogenic period of vulnerability to stress. Nevertheless, the impact of stressful events during adolescence in cardiovascular activity is poorly understood. Therefore, the purpose of this study was to investigate the immediate and long-lasting effects of exposure to stressful events during adolescence in cardiovascular function of rats. To this end, we compared the impact of 10-days exposure to two chronic stress protocols: the repeated restraint stress (RRS, homotypic) and chronic variable stress (CVS, heterotypic). Independent groups of animals were tested 24 h (immediate) or three weeks (long-lasting) following completion of stress period. Exposure to CVS, but not RRS, during adolescence increased basal HR values without affecting arterial pressure, which was followed by augmented power of oscillatory component at low frequency (sympathetic-related) of the pulse interval (PI). RRS enhanced variance of the PI with an increase in the power of both low and high (parasympathetic-related) frequency components. RRS also increased the baroreflex gain. Neither RRS nor CVS affected systolic arterial pressure variability. The RRS-evoked changes in PI variability were long-lasting and persisted into adulthood while all alterations evoked by the CVS were reversed in adulthood. These findings indicate a stress type-specific influence in immediate and long-term effects of stress during adolescence in cardiovascular function. While immediate changes in cardiovascular function were mainly observed following CVS, long-lasting autonomic consequences in adulthood were observed only in animals exposed to RRS during adolescence.

Variabilidade da frequência cardíaca, funções cognitivas e nível de atividade física em pacientes com doença de Alzheimer

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Mutações putativo-causais em genes candidatos associadas à fertilidade de bovinos de corte e bubalinos

Pós-graduação em Genética e Melhoramento Animal - FCAV