Motivated by recent event studies and modeling efforts on pulsating aurora, which conclude that the precipitation energy during these events is high enough to cause significant chemical changes in the mesosphere, this study looks for the bulk behavior of auroral pulsations. Based on about 400 pulsating aurora events, we outline the typical duration, geomagnetic conditions, and change in the pea...

introduction: the purpose of this study was to compare the accuracy of the torque wrenches used in different dental implant systems. methods: we evaluated 42 torque wrenches used in different dental clinics in mashhad, iran, using a digital torque meter (mark 10). high (25, 30 and 35 n·cm) and low (15 n·cm) levels of torque were examined. ten tests were performed on each wrench, and the mean va...

The dynamic behavior of freely propagating premixed flames with large Lewis numbers was computationally simulated using a sixth-order central difference scheme and non-reflective boundary conditions. Results in the linear stage of the instability growth show that the growth rate dramatically decreases with increasing Lewis number and that the large activation energy excites the pulsating instab...

introduction: some clinicians use a handheld screw driver instead of a torque wrench to definitively tighten abutment screws. the aim of this study was to compare the removal torque of one-piece and two-piece abutments tightened with a handheld driver and a torque control ratchet. methods: 40 iti implants were placed in acrylic blocks and divided into 4 groups. in groups one and two, 10 iti one...

We present three novel pulsating solutions of the cubic-quintic complex Ginzburg-Landau equation. They describe some complicated pulsating behavior of solitons in dissipative systems. We study their main features and the regions of parameter space where they exist.

Turbocharging is becoming a key technology for both Spark Ignition (SI) and diesel automotive engines. As regards gasoline engines, turbocharging can help to reduce CO2 emissions when used in conjunction with other technologies, such as engine downsizing, direct injection and variable valve actuation, all managed on the basis of appropriate control strategies. However, the successful applicatio...

high variability in delivering the target torque is reported for friction-style mechanical torque limiting devices (f-s mtlds). the effect of aging (number of use) on the accuracy of these devices is not clear. the purpose of this study was to assess the effect of aging on the accuracy (±10% of the target torque) of f-s mtlds.fifteen new f-s mtlds and their appropriate drivers from three differ...