RELATIVISTIC CALCULATION OF WAVELENGTHS AND E1 OSCILLATOR STRENGTHS IN Li-LIKE MULTICHARGED IONS AND GAUGE INVARIANCE PRINCIPLE

The spectral wavelengths and oscillator strengths for 1s22s (2S1/2) → 1s23p (2P1/2) transitions in the Li-like multicharged ions with the nuclear charge Z=28,30 are calculated on the basis of the combined relativistic energy approach and relativistic many-body perturbation theory with the zeroth order optimized Dirac-Kohn-Sham one-particle approximation and gauge invariance principle performance. The comparison of the obtained results with available theoretical and experimental (compilated) data is performed. The important point is linked with an accurate accounting for the complex exchange-correlation (polarization) effect contributions and using the optimized one-quasiparticle representation in the relativistic many-body perturbation theory zeroth order that significantly provides a physically reasonable agreement between theory and precise experiment.

Comparative Fluid-Structure Interaction Analysis on Influence of Banding Conditions to Ascending Aorta Aneurysm Formation in Rat

Background: Ascending aortic aneurysm in an important cause of mortality in cardiovascular diseases. Stenosis of aortic is considered to be a risk factor as the ascending aortic aneurysm grows. Animal models have been demonstrated that ascending aortic aneurysm could be induced by supra valvular banding of the ascending aortic. Our objective is to compare different banding conditions on the formation of aneurysms for more precise experiment and improving the preclinical value. Therefore, three comparison banding groups of banding altitude, banding severity and banding angle are established based on rat. Then flow pattern, wall shear stress (WSS) and vessel deformation of each model are calculated and discussed using transient two-way fluid-structure interaction (FSI) analysis in order to explore the influence of different banding methods on the generation of ascending aorta aneurysm.Results: Banding methods lead to different shapes or amplitudes of flow beam, WSS and vessel dilation. Eccentric flow beam, local high WSS accompany with vessel dilation are formed above the banding ring in all banding models because of the banding operation compared with normal model. More concentrated flow beam with bigger velocity, higher local WSS and more obvious expansion deformation above the banding ring are prone to happen in the middle segment banding with 60% banding severity and banding angle of 30 degree.Conclusion: According to the results, a higher position, relatively severe banding, and an acute banding angle are more favor to promote the generation of ascending aortic aneurysm.

Improved pivot–slide model of the motion of a curling rock

The pivot–slide model (Shegelski and Lozowski) successfully predicts the slide and curl distances of a curling rock. However, in this model, there is no dependence of the curl distance on the initial velocity, because the ratio between the pivot to sliding times is constant. A refined model is presented, in which the ratio of the pivot to sliding times depends on the stone velocity via two parameters. Confidence limits for these parameters are deduced from experimental data, which show that the pivot–slide ratio depends on the stone velocity. However, precise values of these parameters could not be obtained with this study, as more precise experiment data are needed. The refined model allows one to qualitatively explain two characteristics of the stone trajectory observed in a curling game, namely the bigger final curl with lower initial velocity and the lower curl with the effect of sweeping the ice.

Topology-induced effect in biomimetic propulsive wakes

It is known that the wake pattern observed in a cross-section behind swimming or flying animals is typically characterized by the presence of periodical vortex shedding. However, depending on species, propulsive wakes can differ according to the spatial ordering of the main vortex structures. We conducted a very precise experiment to analyse the role of the topology of the wake in the generation of propulsion by comparing two prototypical cases in a quasi-two-dimensional view. One configuration is jellyfish-like, with symmetric shedding of vortex pairs, and the other is fish-like, with alternating shedding of counter-rotating vortices. Self-propulsion is achieved by the flapping motion of two identical pitching rigid foils, separated by a distance $d$. By keeping the momentum input unchanged, we compared both symmetric and asymmetric flapping modes. For the entire explored range of parameters, the symmetric jellyfish-like mode has shown to produce more thrust than the fish-like asymmetrical one. We show here that this difference is due to a pressure effect related to the ability of each wake to produce or not, strong fluctuations of transversal velocities in the near-wake region.

Simulation model for shapiro time delay and light deflection experiments

The time delay experiment proposed by I.I. Shapiro in 1964 and conducted in the seventies was the most precise experiment of general relativity until that time. Further experimentation has improved the accuracy level of both the time delay and the light deflection experiments. A simulation model is proposed that involves only a simple mass and time transformation factor involving velocity of light. The light deflection and the time delay experiments are numerically simulated using this model that does not use the general relativistic equations. The computed values presented in this paper compare well with recent levels of accuracy of their respective experimental results.

An Account of a Glanders-like Disease occurring in Rangoon

The opportunities of a pathologist at a large Eastern Hospital are many; but his time for research work is short, and his conveniences are few. I, therefore, feel that we, at the Laboratory of the Rangoon General Hospital, are more than usually fortunate to be able to give, within the first two years of the official existence of the Laboratory, an account of a strange disease. Doubtless it is to chance that we owe the first discrimination of the disease; but I hope that it has been by accurate observation and precise experiment that we have sought to fulfil our knowledge. The guidance and application of our observations have been my care, and upon me rests the responsibility for the accuracy of our work; but the work itself has been carried out entirely by my assistants, and to them belongs the credit for the zeal and patient perseverance with which the task has been performed.