There is an increasing number of space missions in which it is proposed to use high accuracy membrane structures and it is envisaged that some of these membranes will remain partially wrinkled in their operational configuration. Previous studies have focussed only on the stress distribution in wrinkled membranes, but for high accuracy applications the amplitude and wavelength of the wrinkles be...

Recombinant sucrose-6-phosphate synthase (SpsA) was synthesized in Escherichia coli BL21DE3 by using the spsA gene of the cyanobacterium Synechocystis sp. strain PCC 6803. Transformants exhibited a 10,000-fold increase in survival compared to wild-type cells following either freeze-drying, air drying, or desiccation over phosphorus pentoxide. The phase transition temperatures and vibration freq...

A planar lipid bilayer (BLM) workstation, used to record currents through actively gating, ion conducting single channels, is a complex apparatus requiring several components working in concert. These components include a means to support the lipid membrane, high gain amplification, shielding of electromagnetic interference and mechanical vibration, mechanisms for stirring and changing solution...

The Koch snowflake is a well known self-similar set whose boundary is a fractal curve. Suppose a vibrating membrane with fixed boundary, i.e. a drum, is shaped like a Koch snowflake. The fundamental modes of vibration of this drum can be modelled by the eigenfunctions of the Laplacian on the snowflake. These, in turn, can be approximated by a discrete problem leading to a matrix eigenvalue prob...

362 NATURE | VOL 399 | 27 MAY 1999 | www.nature.com lateral interactions may allow basilar membrane motion to be selectively enhanced at a particular location where passive vibration is maximal. In nonlinear systems, 10% feedback can have enormous consequences. The likely increase in OHC coupling with increasing frequency, supported by morphological evidence, may explain the finding that tuning...

the purpose of this study was to assess exposure to hand-arm vibration in tiller users, forty users of tiller in northeastern provinces of iran were examined to measure hand-arm vibration parameters such as root mean square acceleration (rms), total equivalent acceleration, vibration dose value (vdv) and crest factor in three directions (x, y, and z) and various operating modes for comparing th...

The two limits for modeling vibrating thin films, viz as a plate or as a membrane, are discussed. In terms of these limits the sources of experimental uncertanties are identified and the advantages of using films which can be modeled as membranes are explained. The mathematical formalism for treating films as vibrating membranes is developed and relations for self-consistency checks are present...

Simplified models have been used to simulate and study the flow-induced vibrations of the human vocal folds. While it is clear that the models' responses are sensitive to geometry, it is not clear how and to what extent specific geometric features influence model motion. In this study geometric features that played significant roles in governing the motion of a two-layer (body-cover), two-dimen...

Cicadas are known to use sound to find a mate. While the mechanism employed by male cicadas to generate loud calling songs has been described in detail, little information exists to explain how their ears work. Using microscanning laser Doppler vibrometry, the tympanal vibrations in the cicada Cicadatra atra are measured in response to acoustic playbacks. The topographically accurate optical me...

String and membrane vibrations cannot be considered as linear above a certain amplitude due to the variation in string or membrane tension. A relevant special case is when the tension is spatially constant and varies in time only in dependence of the overall string length or membrane surface. The most apparent perceptual effect of this tension modulation phenomenon is the exponential decay of p...