Stick-slip friction was observed in articular cartilage under certain loading and sliding conditions and systematically studied. Using the Surface Forces Apparatus, we show that stick-slip friction can induce permanent morphological changes (a change in the roughness indicative of wear/damage) in cartilage surfaces, even under mild loading and sliding conditions. The different load and speed re...

BACKGROUND Accidental needle-stick injuries (NSIs) are a hazard for health-care workers and general public health. Nursing workers are at high risk for occupational exposure to blood-borne pathogens (such as HBV, HCV and HIV) via sharp injuries of needle stick. METHODS This descriptive analytical cross-sectional study was done on 158 nursing workers of Khanevadeh Hospital in Tehran to assess ...

background: deodorant products prevent the growth and activity of the degrading apocrine gland bacteria living in the armpit. common antibacterial agents in the market like triclosan and aluminum salts, in spite of their suitable antibacterial eff ects, increase the risk of alzheimer’s disease, breast and prostate cancers or induce contact dermatitis. th erefore, plant extracts possessing ant...

background: needlestick injuries (nsis) are among the most important occupational injuries for health care workers (hcws). in iran, the problem of exposure to contaminated blood among nursing personnels has not well documented. the aim of this study was to determine the incidence of needlestick injuries in population of nurses in shahroud imam hossein hospital, northern iran. methods: a self-ad...

A puzzling phenomenon of ice-stream flow is the stick–slip motion displayed by Whillans Ice Stream (WIS), West Antarctica. In this study we test the hypothesis that the WIS stick–slip motion has features similar to those of other known stick–slip systems, and thus might be of the same origin. To do so, we adapt a simple mechanical model widely used in seismology to study classic stick–slip beha...

The aim of this study is to establish the effects of stick use on rhythmic bimanual coordination in drummers. Eighteen drummers performed a rapid antiphase coordination task using their fingers and handheld drumsticks. We found no significant differences in the speed of tapping between finger and stick-use tapping, while stick-use tapping had a larger peak force and smaller variability in coord...

Recent modeling studies have explored whether earthquakes begin with a large aseismic nucleation process or initiate dynamically from the rapid growth of a smaller instability in a “cascade-up” process. To explore such a case in the laboratory, we study the initiation of dynamic rupture (stick slip) of a smooth saw-cut fault in a 76mm diameter cylindrical granite laboratory sample at 40–120MPa ...

This thesis investigates the moment, when the drumstick hits the membrane of a drum. Experiments were conducted to obtain information about the interaction of drummer, drumstick and membrane during a single stroke. Using a modified drumstick, the force on the drumstick, the acceleration of the stick’s tip, the duration of the contact between stick and membrane and the sound of the drum were rec...

16 We investigated the acquisition of skill in balancing a stick (52 cm, 34 g) on the fingertip in 17 nine participants using three-dimensional motion analysis. After 3.5 hours practice over 6 18 weeks, the participants could more consistently balance the stick for longer durations with 19 greatly reduced magnitude and speed of stick and finger movements. Irrespective of level of 20 skill, the ...