A new AFM (atomic force microscopy) nanotribology method using a T-shape cantilever with an offaxis tip (Nat Nanotechnol 2:507–514, 2007) has been developed for measuring friction coefficient at nanometer scale. In this method, signals due to both bending and twisting of the T-shape AFM cantilever are detected simultaneously. For a T-shape AFM cantilever, the bending is caused by the normal loa...

A new dynamic model is presented for piezoelectric tube actuators commonly used in high-precision instruments. The model captures coupling between motions in all three axes such as bending motion due to a supposedly pure extension of the actuator. Both hysteresis and creep phenomena are included in the overall actuator model permitting modeling nonlinear sensitivity in the voltage to displaceme...

Rotating shafts are important and responsible components of many machines, such as power generation plants, aircraft engines, machine tool spindles, etc. A transverse shaft crack can occur due to cyclic loading, creep, stress corrosion, and other mechanisms to which rotating machines are subjected. If not detected early, the developing shaft crack can lead to a serious machine damage resulting ...

If exposed to bulk water flow, fish lateral line afferents respond only to flow fluctuations (AC) and not to the steady (DC) component of the flow. Consequently, a single lateral line afferent can encode neither bulk flow direction nor velocity. It is possible, however, for a fish to obtain bulk flow information using multiple afferents that respond only to flow fluctuations. We show by means o...

Removal of large segments of the apical part of the stipe of Coprinus cinereus (extending to about half its length) affected neither the ability of the stipe to show gravitropic bending nor its ability to compensate the curvature so induced and adjust to the vertical. However, gravitropic reaction time was directly proportional to the amount of stipe removed. Application of lateral loads of up ...

Rehabilitation is one of important treatments for postural deformities in patients with Parkinson’s disease. Various possible mechanisms have been suggested. Among these, soft tissue changes such as reduced flexibility and muscle weakness and proprioceptive disintegration that likely induce impaired vertical perception seem to be partially improved by rehabilitation. For soft tissue changes, st...

Design of shear walls is a complex procedure, especially if the cross section of the shear wall is not regular in shape. Shear walls are usually treated like cantilevers fixed at the foundation level. Normally, lift wells are designed as shear walls. The design of shear walls takes horizontal forces into account by shear and bending. Design for shear in the walls can be managed by computing the...

Bi₂Se₃ initially emerged as a particularly promising host of topological physics. However, in actual materials, several issues have been uncovered including strong surface band bending and potential fluctuations. To investigate these concerns, we study nominally stoichiometric Bi₂Se₃ using scanning tunnelling microscopy. Here we identify two distinct distributions of BiSe antisites that act as ...

A new criterion for the optimum design of curved dielectric waveguides is proposed. The bends designed according to this model are named matched bends. In the matched bend, the suitable choice of both bending radius and bending angle reduces the total losses of the bend and avoids the leaky-mode excitation at the end of the bend. For a given angle, a discrete number of bending radii that satisf...