structural dynamic parameters: natural period, shape modes and damping ratio of vibration, play a decisive role on the seismic behavior of those structures. there are several methods for determining of the structural dynamic parameters, such as: free vibration, ambient vibration and force vibration tests. in this research the structural response of a three-story building (the natural frequencie...

the present research simulates time-periodic unsteady transonic flow around pitching airfoils via the solution of unsteady euler and navier-stokes equations, using time spectral method (tsm) and compares it with the traditional methods such as bdf and explicit structured adaptive grid method. the tsm uses a fourier representation in time and hence solves for the periodic state directly accordin...

Among fluctuations of instantaneous heart rate (IHR) in newly hatched chicks, heart rate (HR) oscillation with a mean frequency of 0.7 Hz has been designated as Type II HR variability characterized by low frequency (LF) oscillation [Comp. Biochem. Physiol. Part A 124 (1999) 461]. In response to exposure to lowered ambient temperature (Ta), chick hatchlings raised their HR baseline accompanied w...

Oscillatory neural activities have been implicated in various types of information processing in the CNS. The procerebral (PC) lobe of the land mollusk Limax valentianus shows an ongoing oscillatory local field potential (LFP). Olfactory input increases both the frequency and spatial synchrony of the LFP oscillation by a nitric oxide (NO)-mediated mechanism, but how NO modulates the activity in...

The reaction of CH3O2 radicals with acetaldehyde on the solid surface of NH4NO3 has been studied in a flow capillary reactor at low pressure and room temperature. The experiments were performed using EPR spectrometer combined with the kinetic method of radicals freezing. Peroxy radicals revealed an oscillation complex behavior during the process regarding to the phenomenon of radicals multiplic...

The important characteristic of sea waves is their high energy density, which is the highest among renewable energy sources. Having up to 2700 km. of shoreline, Iran has a great potential in construction of offshore wave buoys (hereafter called OWB). In this article a OWB model with the possibility of assembling different buoy configurations is introduced. The system is exposed to regular and i...