the mixing behavior of the gas-liquid phase in three loop bioreactors was investigated. a gas-induced external airlift loop bioreactor (ealb), a forced-liquid vertical tubular loop bioreactor (vtlb) and a forced-liquid horizontal tubular loop bioreactor (htlb) were used for mixing studies as well as biomass production from natural gas. the effect of design parameters, riser to downcomer cross s...

local site conditions have a strong effect on ground response during earthquakes. two important soil parameters that control the amplification effects of seismic motions by a soil column are the soil hysteretic damping ratio and shear wave velocity. this paper presents the results of in situ damping ratio measurements performed using continuous surface wave attenuation data at a site in semnan ...

In this paper, a new guidance law is designed to improve the performance of a homing missiles guidance system in terminal phase. For this purpose first of all, the two dimensions equations of motion are formulated, then the approximation dynamic of missile control loop is added to these equations which are nonlinear whit unmatched uncertainty. Then, a new adaptive back-stepping method is develo...

In this paper a new method is introduced and investigated for removing the destabilizing effects of time-delay parameter in control loops. The concept of the method is taken from the knowledge concerning the dynamic behaviour of irrational transfer functions (Ir-TF), which is discussed and investigated elswhere in frequency response domain and is explained briefly here. Ir-TFs, which are we...

After extraction, space closure is an essential part of orthodontic treatment which needs thorough understanding of biomechanics used for space closure. Orthodont ic appl iances are being ref ined wi th passage of t ime . This re f inement has reduced the physical e f fort pu t for th in treatment , but does not el imina te the need for an orthodont ist to think, unders tand and apply basic pri...