منابع مشابه
Re-centering variable friction device for seismic control of structures
This paper investigates the seismic response control of a nonlinear benchmark building with a new re-centering variable friction device (RVFD). The RVFD consists of three parts: (i) a friction generation unit, (ii) a piezoelectric actuator, and (iii) shape memory alloy wires. The friction unit and piezoelectric actuator compose the first subcomponent of the hybrid device that is a variable fric...
متن کاملResearch on Three-point Centering Device of Cylindrical Drill Pipe
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...
متن کاملScience with a punch
There are changes afoot in the way that US granting agencies, most notably the NIH, evaluate proposals. Change can be a good thing, and it is probably high time that the NIH reassessed how grants are evaluated. Frankly, I was becoming blasé about the entire granting process. It seemed that once I became inured to the low probability of funding, competition from the mega-labs, and the shift towa...
متن کاملExperimental atrial septal defect closure with a new, transcatheter, self-centering device.
BACKGROUND Despite two decades of research, a transcatheter atrial septal defect closure device is not available for clinical use. We have designed a new superelastic Nitinol-Dacron, double-disk, self-centering, atrial septal defect closure device and studied its efficacy in a canine model of atrial septal defects. METHODS AND RESULTS Atrial septal defects were created surgically in 20 adult ...
متن کاملA punch drunk jockey?
The case is reported of a retired professional jockey with progressive memory loss. The concern is that he may be suffering from chronic traumatic encephalopathy or the "punch drunk syndrome".
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
ژورنال
عنوان ژورنال: Scientific American
سال: 1902
ISSN: 0036-8733
DOI: 10.1038/scientificamerican11151902-324