The secular evolution of comet nucleus rotation states subject to outgassing torques is studied. The dynamical model assumes that the nucleus inertia ellipsoid is axially symmetric. The outgassing torques acting on the surface are modeled using standard cometary activity formulae. The general rotational equations of motion are derived and separately averaged over the fast rotational dynamics te...

Ormia ochracea (Diptera, Tachinidae) are acoustic parasitoids of crickets that have one of the most directionally sensitive auditory systems known. We studied dynamic characteristics of walking phonotaxis in these flies in response to variations in sound source azimuth, and compared phonotaxis of flies in freely walking conditions to tethered flies walking on a treadmill. Motor patterns at the ...

15N NMR relaxation times in perdeuterated HIV-1 protease, complexed with the sub-nanomolar inhibitor DMP323, have been measured at 600 and 360 MHz ~H frequency. The relative magnitudes of the principal components of the inertia tensor, calculated from the X-ray coordinates of the protein drug complex, are 1.0:0.85:0.44. The relation between the TI/T2 ratios observed for the individual backbone ...

The Yarkovsky--O'Keefe--Radzievskii--Paddack (YORP) effect governs the spin evolution of small asteroids. axial component YORP, which alters rotation rate asteroid, is mostly independent its thermal inertia, while obliquity very sensitive to model asteroid. Here we develop a semi-analytic theory for YORP. We integrate an approximate over surface and find analytic expression in terms two YORP co...

The subject of the study is underground pipeline vibration in a vertical plane, considering inertia rotation and transverse shear. A system differential equations motion an with natural boundary initial conditions under spatial seismic loading derived article. From formulas obtained, it necessary to determine internal forces sections structure. Research methods are based on variational equation...

Theropod dinosaurs attained the largest body sizes among terrestrial predators, and were also unique in being exclusively bipedal. With only two limbs for propulsion and balance, theropods would have been greatly constrained in their locomotor performance at large body size. Using three-dimensional restorations of the axial bodies and limbs of 12 theropod dinosaurs, and determining their rotati...

The use of high penetration converter-interfaced renewable energy (RE) based microgrids (MGs), due to the absence rotational masses from conventional synchronous generators (SGs), may lead a lack inertia, which steeper frequency and voltage fluctuations that in turn cause instability issues challenges normal operation sensitive loads. To suppress these enhance MGs stability, novel model predict...