The paper shows how the diffusive movement of ions through a channel protein can be described as a chemical reaction over an arbitrary shaped potential barrier. The result is simple and intuitive but without approximation beyond the electrodiffusion description of ion movement.

We introduce a model detector which registers the passage of a particle through the detector location, without substantially perturbing the particle wave function. (The exact time of passage is not determined in such measurements.) We then show that our detector can operate in a classically forbidden region and register particles passing through a certain point under a potential barrier. We sho...

This paper presents a multi-link magnetic wheeled pipeline robot (PR-I), which is flexible and modular robotic mechanism. It designed for inspection, cleaning or disinfection of central air conditioning ventilation duct. PR-I can adapt to complex terrain, move in the ducts freely. A novel wheel proposed wall climbing, circumferentially embedded with rectangular permanent magnets. Firstly, climb...

background : the application of ventilation systems in industries and workplaces is with the aim of improving environmental conditions for employees. the lack of appropriate ventilation system components design and control methods result in the production of sound and vibration in most components. the purpose of this study was to determine the role of the pad isolator in controlling vibration a...

aim : to assess the complications of bile duct injury in laparoscopic cholecystectomy in loghman medical center, tehran. background : the incidence of complications of laparoscopic cholecystectomy has increased dramatically since the introduction and widespread use of laparoscopic cholecystectomy.  patients and methods : from january 1998 to january 2002, a total of 155 laparoscopic cholecystec...

A jet of fluid discharging into a cross stream, also known as Jet In Crossflow (JICF), has received many experimental and numerical investigations. In addition to the fundamental understanding of threedimensional mixing and shear flow characteristics, the fluid dynamics research community often regarded it as a benchmark test case for validating turbulence models. Although many authors consider...