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The model widely used in the fatigue crack growth study in materials science and fracture mechanics is the Paris-Erdogan, which relates the stress intensity factor with the subcritical crack growth, under a fatigue regime. In this work, a seven degree polynomial is used as an alternative to model the crack propagation behavior and to be able to analyze the three regions charts of the cycles by load, in contrast to the common model that it performs at a slight approximation of the propagation phase of the trinca (region II). Finally, a comparison has been made between the proposed model and the secant method by the ASTM 647,2000 standard that adjusts the points obtained experimentally. This proposed equation is new as another alternative analytical model for which the adjustment parameter “R” are compared in relation to the classical approach in a aeronautical ABNT 4130 steel.

Brazilian and foreign companies operating in Brazil in the last 30 years have been using automated productive resources, especially robots. These 3 decades doesn´t seem to have been enough to develop in the actors involved with robots an adequate professional awareness. If we consider the predictive security and ergonomic aspects involved, we notice that there are critical failures on handling these situations. So in this study we tried to observe the presence of the human being in some workstations that operate with robots in the Brazilian Southeastern region.

This study considered whether chronic schizophrenics with positive and negative syndromes represent distinct subtypes. From a survey of 47 schizophrenic inpatients, 18 showed preponderance of productive or deficit features, and four were mixed. The discrete groups were compared on clinical symptoms, cognitive tests, demographic and historical data, and drug side effects. They were significantly distinguished on most criterion symptoms and affect scales but, otherwise, essentially comparable in psychopathology and extrapyramidal symptoms. The tests revealed similar levels of intellectual impairment and visual-motor deficit, yet the negative patients displayed more primitive cognitive mode and greater psychomotor retardation. They also proved older, less educated, more often born in wintertime, hospitalized later in life, and less heavily medicated. The results supported the validity of the positive-negative dimension for identifying schizophrenic subtypes and suggested etiological implications regarding developmental deficiency.