566 research outputs found
Testing and validation of a Β; algorithm for cubesat satellites
For most satellite missions, it is essential to decrease the satellite angular velocity. The Β algorithm is a common algorithm to stabilize the spacecraft by using magnetorquers. Controlling the satellite using the magnetorquers is part of the attitude control subsystem
detumbling mode. Due to oscillating disturbances in the space environment, the required initial conditions needs analysis. As a consequence, the satellite stays in Β
detumbling mode for the entire operation. In the detumbling mode, the spacecraft oscillates around its spatial axes. The
purpose of this paper is to extend the Β algorithm with a disturbances compensation module and to achieve reduction of
satellite’s angular velocity. The developed algorithm is found to be able to reduce satellite’s angular velocity up to 10-11 degrees
The survey of the effect of ginger extract on gastric residual volume in mechanically ventilated patients hospitalized in the Intensive Care Units
Background and purpose: Delayed gastric emptying in mechanically ventilated patients is common. According to evidences, Ginger can accelerate gastric emptying. This study aimed to determine the effect of ginger extract on gastric residual volume of patients admitted to the Intensive Care Unit. Materials and Methods: In this double-blind randomized controlled clinical trial with before and after schematization, 24 mechanically ventilated patients hospitalized in ICUs were divided into two groups, intervention group (12 patients) and control group (n = 12) after matching for sex and severity of disease. After 48 hours of feeding with a standard gavage solution, the intervention group received 120mg of ginger extract in 4 days and the control group received 5 ml water as placebo in 4 days. The mean residual volume was recorded in the fifth and the sixth days. Data analysis was done with independent and paired T-tests at a significance level of 0.05. Results: The mean residual volume in the first 48 hours was not significantly different between the groups. But after 48 hours of starting treatment, the average of mean and standard deviation of the residual volume in the fifth and sixth days were (24.58±16.81) in intervention group and (108.33±15.09) in control group that according to the Independent T-test showed a significant difference (P <0.0001). Discussion and Conclusion: The result of this study showed that ginger extract reduces gastric residual volume in mechanically ventilated patients hospitalized in intensive care units compared with placebo. © 2013 AENSI Publisher All rights reserved
Energy states of the Hulthen plus Coulomb-like potential with position-dependent mass function in external magnetic fields
We need to solve a suitable exponential form of the position-dependent mass
(PDM) Schr\"odinger equation with a charged particle placed in the Hulthen plus
Coulomb-like potential field and under the influence of the external magnetic
and Aharonov-Bohm (AB) flux fields. The bound state energies and their
corresponding wave functions are calculated for spatially-dependent mass
distribution function of a physical interest. A few plots of some numerical
results to the energy are shown.Comment: 8 pages, 8 figures, Chinese Physics B (2017
Relativistic Killingbeck Energy States Under an External Magnetic Fields
We address the behavior of the Dirac equation with the Killingbeck radial
potential including the external magnetic and Aharonov-Bohm (AB) flux fields.
The spin and pseudo-spin symmetries are considered. The correct bound state
spectra and their corresponding wave functions are obtained. We seek such a
solution using the biconfluent Heun differential equation method. Further, we
give some of our results at the end of this study. Our final results can be
reduced to their non-relativistic forms by simply using some appropriate
transformations. The spectra, in the spin and pseudo-spin symmetries, are very
similar with a slight difference in energy spacing between different states.Comment: 18 pages, 8 figure
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