An overview on a nonideal system with three and a half degrees of freedom

The present paper studies a system comprised of two blocks connected by springs and dampers, and a DC motor with limited power supply fixed on a block, characterizing a non-ideal problem. This DC motor exciting the system causes interactions between the motor and the structure supporting it. Because of that, the non-ideal mathematical formulation of the problem has one and a half extra degree of freedom than the ideal one. A suitable choice of physical parameters leads to internal resonance conditions, that is, its natural frequencies are multiple of each other, by a known integer quantity. The purpose here is to study the dynamic behavior of the system using an analytical method based on perturbation techniques. The literature shows that the averaging method is the more flexible method concerning non-ideal problems. Summarizing, an steady state solution in amplitude and phase coordinates was obtained with averaging method showing the dependence of the structure amplitudes with the rotation frequency of the motor. Moreover, this solution shows that on of the amplitude coordinates has influence in the determination of the stationary rotation frequency. The analytical solution obtained shows the presence of the rotation frequency in expressions representing the oscillations of the structure, and the presence of amplitude coordinates in expressions describing the dynamic motion of the DC motor. These characteristics show the influence not only of the motor on structure but also of the response of the structure on dynamical behavior of the motor. Copyright © 2005 by ASME.

No more!: the right of women to live a life free of violence in Latin America and the Caribbean

Includes bibliography

Embryos refrozen-thawed by vitrification lead to live births: Case report

Objective: To describe two successful cases of utilizing refrozen blastocysts by vitrification derived from supernumerary embryos. Design: Case report. Setting: Private fertility clinic. Subjects: Two infertility couple. Interventions: Refrozen blastocysts by vitrification derived from supernumerary embryos. Main outcome measures: Obstetric and pediatric results. Results: Two pregnancies obtained from refrozen-warmed blastocysts led to two healthy babies being born without clinical or genetic problems. Conclusion: These case reports support the notion of safely repeating cryopreservation. However, despite these favorable results, there is still a need for prospective controlled studies on the obstetric and neonatal repercussions of refreezing and of vitrification in particular. © 2010 Middle East Fertility Society.

Composição mineral da carcaça e dos cortes da carcaça de ovinos jovens e adultos

Aiming to evaluate the mineral composition (iron, calcium and sodium) of the carcass and carcass cuts of meat from different ovine categories, 18 1/2 Ile de France 1/2 Polwarth sheeps (6 uncastrated lambs, 6 discarded ewes and 6 discarded wethers) were used. Animals were in grazing system based on Tifton - 85 pastures and were supplemented with concentrate. Lambs were slaughtered at 32 kg of live weight, at around 5 months of age. Ewes and wethers were slaughtered with 55 kg and 60 months of age. The iron values were differents between categories for those valued cuts muscles, with higher average to legs muscles from adults ovine of 3.86 mg/100g with regard to lambs of 1.91 mg/100g, respectively. The iron values of the muscles from half carcass didn't differ for that animal category, with 3.38 mg/100g average. The calcium values in muscles from half carcass and leg cut were higher to wethers (9.84 e 7.35 mg/100g), intermediaries to ewes (6.28 e 6.54 mg/100g) and smallers values to lambs (5.30 e 4.22 mg/100g). There wasn't differences for sodium values to valued categories and muscles, with values around 56.75 mg/100g. In conclusion, the sodium values are similar between animals categories and from differents carcass muscles and that the iron and calcium values present differences.

El comercio exterior latinoamericano en el primer semestre de 1958 = Latin American foreign trade in the first half of 1958

Incluye Bibliografía

Youth expectations and rural development

Includes bibliography

The United Nations and ECLAC at the half-century mark of the Organization

Includes bibliography

Capital formation in Latin America: one and a half century of macroeconomic dynamics

Includes bibliography

From doubly labelled water to half-life; validating radio-isotopic rubidium turnover to measure metabolism in small vertebrates

The doubly labelled water method (DLW) is widely used to measure field metabolic rate (FMR), but it has some limitations. Here, we validate an innovative technique for measuring FMR by comparing the turnover of isotopic rubidium (86Rb kb) with DLW depletion and the rate of CO2 production (V·co2) measured by flow-through respirometry (FTR) for two dunnart species (Marsupialia: Dasyuridae), Sminthopsis macroura (17 g) and Sminthopsis ooldea (10 g). The rate of metabolism as assessed by V·co2 (FTR) and 86Rb kb was significantly correlated for both species (S. macroura, r2 = 0·81, P = 1·19 × 10-5; S. ooldea, r2 = 0·63, P = 3·84 × 10-4), as was V·co2 from FTR and DLW for S. macroura (r2 = 0·43, P = 0·039), but not for S. ooldea (r2 = 0·29, P = 0·168). There was no relationship between V·co2 from DLW and 86Rb kb for either species (S. macroura r2 = 0·22, P = 0·169; S. ooldea r2 = 0·21, P = 0·253). We conclude that 86Rb kb provided useful estimates of metabolic rate for dunnarts. Meta-analysis provided different linear relationships between V·co2 and 86Rb kb for endotherms and ectotherms, suggesting different proportionalities between metabolic rate and 86Rb kb for different taxa. Understanding the mechanistic basis for this correlation might provide useful insights into the cause of these taxonomic differences in the proportionality. At present, it is essential that the relationship between metabolic rate and 86Rb kb be validated for each taxon of interest. The advantages of the 86Rb technique over DLW include lower equipment requirements and technical expertise, and the longer time span over which measurements can be made. The 86Rb method might be particularly useful for estimating FMR of groups for which the assumptions of the DLW technique are compromised (e.g. amphibians, diving species and fossorial species), and groups that are practically challenging for DLW studies (e.g. insects). © 2013 British Ecological Society.

ILPES: su función en la segunda mitad de los 80. Líneas de trabajo para 1987 y 1988-1990 = ILPES: its role in the second half of the 1980s. Guidelines for activities in 1987 and 1988-1990

Presenta una breve reflexión sobre nuevos aspectos de la planificación y de la coordinación de políticas públicas, pensadas ambas desde la perspectiva de América Latina y el Caribe. Contiene la propuesta de programa de trabajo para 1987: asesoría, capacitación, coordinación técnica, proyectos específicos, de las unidades descentralizadas (Caribe e Istmo Centroamericano), y lineamientos para 1988-1990.

Síntesis: planificación y políticas públicas en 1982-1984 y perspectivas para la segunda mitad de la década = Summary: public planning and policies in 1982-1984 and prospects for the second half of the decade

Incluye Bibliografía

Vivências de adolescentes anoréxicas

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

Produção e caracterização do complexo xilanolítico de Penicillium janczewskii

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Técnica dos isótopos estáveis para determinar o turnover de carbono nas fezes, no sangue e plasma de bovinos jovens confinados

Pós-graduação em Zootecnia - FMVZ