34,474 research outputs found
Towards Long-endurance Flight: Design and Implementation of a Variable-pitch Gasoline-engine Quadrotor
Majority of today's fixed-pitch, electric-power quadrotors have short flight
endurance ( 1 hour) which greatly limits their applications. This paper
presents a design methodology for the construction of a long-endurance
quadrotor using variable-pitch rotors and a gasoline-engine. The methodology
consists of three aspects. Firstly, the rotor blades and gasoline engine are
selected as a pair, so that sufficient lift can be comfortably provided by the
engine. Secondly, drivetrain and airframe are designed. Major challenges
include airframe vibration minimization and power transmission from one engine
to four rotors while keeping alternate rotors contra-rotating. Lastly, a PD
controller is tuned to facilitate preliminary flight tests. The methodology has
been verified by the construction and successful flight of our gasoline
quadrotor prototype, which is designed to have a flight time of 2 to 3 hours
and a maximum take-off weight of 10 kg.Comment: 6 page
Active role of elongation factor G in maintaining the mRNA reading frame during translation.
During translation, the ribosome moves along the mRNA one codon at a time with the help of elongation factor G (EF-G). Spontaneous changes in the translational reading frame are extremely rare, yet how the precise triplet-wise step is maintained is not clear. Here, we show that the ribosome is prone to spontaneous frameshifting on mRNA slippery sequences, whereas EF-G restricts frameshifting. EF-G helps to maintain the mRNA reading frame by guiding the A-site transfer RNA during translocation due to specific interactions with the tip of EF-G domain 4. Furthermore, EF-G accelerates ribosome rearrangements that restore the ribosome's control over the codon-anticodon interaction at the end of the movement. Our data explain how the mRNA reading frame is maintained during translation
Nucleon Mass Splitting at Finite Isospin Chemical Potential
We investigate nucleon mass splitting at finite isospin chemical potential in
the frame of two flavor Nambu--Jona-Lasinio model. It is analytically proved
that, in the phase with explicit isospin symmetry breaking the proton mass
decreases and the neutron mass increases linearly in the isospin chemical
potential.Comment: 3 pages and no figure
Pupillometry, a bioengineering overview
The pupillary control system is examined using a microprocessor based integrative pupillometer. The real time software functions of the microprocessor include: data collection, stimulus generation and area to diameter conversion. Results of an analysis of linear and nonlinear phenomena are presented
Unlocking the Doors to Patient Satisfaction in Pediatric Orthopaedics
Background Many hospitals continue to struggle to improve patient satisfaction as the identification of tangible quality improvement areas remains difficult Medicare hospital payments are linked to patient satisfaction and hospitals\u27 HCAHPS scores, which has contributed to the growing influence of patient satisfaction measures Investigation into the major drivers of patient satisfaction in the pediatric clinical arena has not been thoroughly pursued To determine the main drivers of patient experience in pediatric orthopaedics, we performed an analysis of patient satisfaction surveys collected from outpatient pediatric orthopaedic practices at 5 locations in 3 states Hypothesis: the patient-physician relationship is the most important factor in patients\u27 assessment of their experiences These results may have significance in aiding pediatric orthopaedic clinics in their Quality Assurance/Quality Improvement plans of enhancing the patient experiencehttps://jdc.jefferson.edu/pedsposters/1000/thumbnail.jp
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