In the process of tightening up and screwing off the iron roughneck, it is required that the center of clamping pliers and the center of drill pipe are coincident, so as to avoid the damage of the circular guide in clamping system, and to ensure the iron roughneck work normally. While the traditional method of centering is artificial in iron roughneck, its precision is low, so it is easy to dam...

BACKGROUND Piezosurgery is a relatively new osteotomy technique using microvibrations of scalpels at ultrasonic frequencies to perform safe and effective osteotomies without damage to adjacent soft tissue, which is widely used in spinal, oral, and maxillofacial surgery. We hypothesized that such a device could also be useful in cervical laminoplasty. The purpose of this study was to compare the...

Background: In 2008, the Southern California Earthquake Center in collaboration with the U.S. Geological Survey Earthquake Hazards Program launched the first annual Great ShakeOut, the largest earthquake preparedness drill in the history of the United States. Materials and Methods: We collected online survey data from 2052 campaign registrants to assess how people participated, whether audience...

The San Francisco, California, bay area is subject to continuous seismic risk. One particular response has been the development of community-based training programmes designed to teach residents basic emergency response skills. Citizens are taught emergency medical techniques, search and rescue, fire suppression and other fundamental response skills. Current estimates in the Bay Area place the ...

Due to ultraviolet flux in the surface layers of most solar bodies, future astrobiological research is increasingly seeking to conduct subsurface penetration and drilling to detect chemical signature for extant or extinct life. To address this issue, we present a micro-penetrator concept (mass < 10 kg) that is suited for extraterrestrial planetary deployment and in situ investigation of chemica...

Many vibration-exposed workers have been found to suffer from muscle fatigue and decreased grip strength. Therefore in order to quantify and determine safe levels of human exposure to vibration, measurements and analysis of significance vibration factors are necessary. There are three main objectives in this study. The first one is to investigate the characteristics of vibration factors (vibrat...

external fluted feed rolls are commonly used in grain drills. the fluted feed roll meters a volume of seeds and does not singulate the seeds as do the precision planters; therefore, there will be inherent variation in the number of seeds delivered per unit of time. this research was conducted to investigate the effect of seed meter drive shaft and ground speeds and outlet positions in a grain d...

objective: generated acoustic trauma by suction and drill may cause sensorineural hearing loss after tympanomastoid surgery. this study was carried out to determine the relationship of sensorineural hearing loss and chronic otitis media surgery at ahvaz jundishapur university of medical sciences in iran. material and methods: this prospective study included 386 patients of chronic middle ear di...

We present a drilling method that is based on the phenomenon of local hot spot generation by near-field microwave radiation. The microwave drill is implemented by a coaxial near-field radiator fed by a conventional microwave source. The near-field radiator induces the microwave energy into a small volume in the drilled material under its surface, and a hot spot evolves in a rapid thermal-runawa...