in this paper, the flow of couple stress fluid is investigated in a helical screw rheometer (hsr). by unwrapping the channel, lands, and the outside rotating barrel, the geometry of hsr is approximated as a shallow infinite channel. both one- and two-dimensional analysis of the problem is presented using rectangular coordinates. in either case an exact solution of the flow problem is presented ...

Nanopumps conducting fluids through nanochannels have attracted considerable interest for their potential applications in nanofiltration, water desalination and drug delivery. Here, we demonstrate by molecular dynamics (MD) simulations that a nano screw pump is designed with helical nanowires embedded in a nanochannel, which can be used to drive unidirectional water flow. Such helical nanowires...

The development of sensor pins which can be easily integrated into ball screw drives for preload measurement is described in this paper. The sensor’s base body consists out of a steel pin with a special shaped load region. This complex surface is coated and structured with a sensory thin film system based on a hydrogenated carbon layer. The layer shows an excellent tribological stability combin...

We read with great interest the recently published paper by Rezq et al. (1), which described the experience of the authors with cardiac tamponade complicating transcatheter aortic valve replacement (TAVR). The authors should be congratulated on sharing their experience and techniques to avoid this complication, which is associated with poor outcome. The authors identified that 52.9% of the card...

This article is devoted to the problem of linear positioning output link a mechatronic module (MM), made on basis ball screw (ball screw). The analysis typical schemes for constructing an MM controller using signals from radial position sensors rotor and discrete indicator in working stroke section with possibility implementing emergency (emergency) power off entire system event extending beyon...

Purpose: To investigate whether helical blade implant systems have advantages in terms of tip apex distance (TAD) and cut-out rate in comparison to conventional lag screws for intertrochanteric fractures in a geriatric population. Methods: Relevant articles were sourced from the MEDLINE, Embase, Ovid and Cochrane Library databases from inception through March 2015. All randomized controlled tri...

Hard whirling is a highly efficient and green process for precision ball screw machining. Due to the intermittent cutting characteristics helical motion of tool, forces are periodic time-varying, making it extremely challenging establish an accurate force model. This paper proposes modelling method based on transient geometric uncut chips, subject essential link between chips forces. The time-v...