In this paper, vibrations and bifurcation of a damped system consists of a mass grounded by linear and nonlinear springs and a nonlinear damper is studied. Nonlinear equation of motion is derived using Newton’s equations. Approximate analytical solutions are obtained using multiple time scales (MTS) method. For free vibration, the approximate analytical results are compared with the numerical i...

nowadays, planning is no longer considered merely a scientific and technical career nor agovernment responsibity. it rather functions as a bridge connecting the planners to institutional changes. in otherwords, the planning theory does not develop in a social, economic and political vacuum, but is formulated byindividuals in social situations with the aim of clarifying the enviroment recommendi...

the main rock mass classification systems make use of similar rock mass parameters. due to lack of comprehensive estimation systems, determining the real specifications of jointed rocks faces some difficulties. a vast number of parameters with various degrees of impact are involved in such definitions. combination impact of all the effective parameters is to be figured out in order to come up w...

This paper discusses grounding practices used on electric distribution systems above 600 Volts. In particular, the paper concentrates on the three-phase fourwire, multi-grounded neutral system that is extensively used in North America. The paper addresses the benefits of the multi-grounded power system and makes comparisons with other grounding system designs including ungrounded; three-wire si...

occupational health and safety systems have a unique role in sustainable development of hazardous industries. the aim of this research is investigating and assessing of h3se performance excellence systems. to achieve mentioned goal by qualitative approach and multi grounded theory tools h3se excellence model was described. mentioned tools contain two qualitative research methods (meta synthesis...

Older Colombians face significant adversities: poverty, violence and displacement. However, there is evidence that Latinos are often resilient. We examine resilience in older Colombians living in poverty using an ecological framework that identifies three levels: individual; community; and societal. In this paper we examine data from 16 semi-structured interviews with older Colombians that expl...