In this study the interaction between self-excited and paramet rically excited oscillations in two-degree-of-freedom systems with quadratic nonlinearities is investigated. The fundamental parametric resonance of the first mode and 3:1 internal resonance is considered, followed by 1:2 internal and parametric resonances of the second mode. The method of multiple time scales is applied to derive f...

-The steady-state creep deformation behavior of a cast two phase gamma TiA1 alloy having the composition Ti-48AI 1Nb (a t . ° ) has been studied. Tension creep tests using the stress increment technique (a~ < cr 2 < or3) were conducted over the temperature range of 704-850°C at constant initial applied stress level of 103.4-241.3 MPa. The activation energy for creep over the temperature and str...

the understanding of the dynamic behavior of distillation columns has received considerable attention because distillation is one of the most widely used unit operations in chemical process industries. this paper reports a dynamic simulation study of the possible distillation columns sequences of dew pointing unit in the second phase of south pars gas refinery. in this unit, three columns are u...

The relaxation by creep recovery of plasticized poly lvinyl chloride) (PVC) was tested in relation to applied stresses and working temperatures. The relaxation time increased with stress but decreased with temperature. From the temperature dependence of relaxation times, an energy of 0.21 eV was found to activate the creep recovery process. It is thought that creep recovery is effected by the c...

The potential for nanofuels as one of the clean sources of energy on account of its enhanced combustion performance coupled with low emissions has been established. Considering the importance of the fuel evaporation phase in the entire combustion process, this work presents an attempt at applying the steady state analysis equations to nanofuel experimental data obtained from the li...

This paper deals with a lumped-parameter dynamic simulation of a single-effect LiBr-H2O absorption chiller. In many studies the thermodynamic properties of LiBr-H2O solution were taken from some approximate relations causing the results to be somewhat inaccurate. These relations were used to solve simultaneous differential equations involving the continuity of species constituting the LiBr-H2O ...

Operability analysis as one of the most important bridges between process design and process control helps the process designer to investigate the control issues quite early in the design stage. Recently, Vinson and Georgakis suggested a steady state geometrical operability index as a quantitative measure for assessment of process operability. In...

Abstract The rheology of the upper mantle impacts a variety geodynamic processes, including postseismic deformation following great earthquakes and post-glacial rebound. rocks is controlled by olivine, most abundant mineral. mechanical properties olivine at steady state are well constrained. However, physical mechanism underlying transient creep, an evolutionary, hardening phase converging to a...

This investigation deals with multi server queue with balking. The customers arrive in poisson fashion and independent of time, under the assumption that system is initially empty. The number of customers in the system is stochastically increasing and distributed in steady state (stationary state) as required. The expressions for the measure of the speed of convergence from transient state to s...