Compressing Aerodynamic Hazard Data

Data compression of three-dimensional computational fluid dynamics (CFD) simulation data is crucial to allow effective data-streaming for drone navigation and control. This problem is computationally challenging due to the complexity of the geometrical features present in the CFD data, and cannot be tackled by standard compression techniques such as sphere-tree. In this report, we present two different methods based on octree and cuboid primitives to compress velocity isosurfaces and volumetric data in three dimensions. Our volume compression method achieves a 1400 compression rate of raw simulation data and allows parallel computing.

Arc extinction with nitrogen at 1-40 bar in a puffer-like contact configuration

To develop cost-efficient subsea switchgear for large sea depths, the extinction of arcs under high filling pressures must be understood. In this work, arc-extinction experiments have been performed with a puffer-like contact configuration using nitrogen at different filling pressures as the current interruption medium. The main finding is that, for the given contact configuration, the currentinterruption capability was lower at 20 and 40 barabs than at 1 and 10 barabs. While higher pressures result in higher cooling flow rates and longer flow times given the same puffer volume, compression spring and nozzle geometry; it does not necessarily improve the arc-extinction capability. This is probably because higher filling pressures increase the arc voltage and total energy dissipated in the arcing zone. Because the filling pressure greatly influences the flow characteristics, the puffer design should be optimized for each pressure level.

Interparticle Spacing Effect among Quantum Dots with High-Pressure Regulation

In this paper, we explore whether interparticle spacing affects steady-state and transient-state optical properties by comparing close-packed CdSe/ZnS–quantum dots (QDs) and CdSe/ZnS–QDs dispersed in polymethyl methacrylate (PMMA). High–pressure is an effective physical means to adjust the interparticle spacing of QDs, which may artificially expand the application of QDs further. The results under high–pressure indicate that it is the reduced interparticle spacing rather than the enhanced quantum confinement effect with volume compression that has a stronger effect on exciton relaxation of CdSe/ZnS–QDs. This work is hoped to help us further understand the effect of interparticle spacing among QDs in various integrated environments.

Alteration of macrohaemodynamics in different modes of retropneumoperitoneum

Aim of the study. To study alterations in macrohaemodynamics in diff erent modes of retropneumoperitoneum during retroperitoneal surgery. Material and methods. A total of 58 patients aged 40-60, both male and female, with previous surgeries on renal cysts through retroperitoneal approach were studied aft er distribution between 2 groups. In the fi rst group, the pressure did not exceed 12 mm Hg. The RPP in the second group was observed to be 12-16 mm Hg. During the surgical intervention, analysis of the cardiovascular system values was carried out using the method of volume compression oscillometry. Results. Evaluation of macrohaemodynamics revealed significant deviation of the indices in patients with high RPP (group 2). Elevated true systolic pressure was revealed, as well as cardiac output decrease by 20 %, decrease of the cardiac index by 24 % and decrease of the stroke volume by 11 %. Th e patients treated with application of the highest gas pressure in the retroperitoneal space were revealed to have decrease in the linear velocity of blood fl ow by 17 % and elevation of total systemic vascular resistance (TSVR) by 12 %. Conclusion. Th erefore, the RPP value of 12-16 mm Hg exerts significant influence on the patient’s macrohaemodynamic status

The study on the mechanical properties of magnetorheological elastomers under triaxial compression

In order to design magnetorheological elastomers (MREs) based craftsmanship for metal forming, a comprehensive study on the mechanical properties of MREs under triaxial compression is required. An experimental setup integrating free compression and triaxial compression is designed to characterize isotropic MREs specimens under compression mode. The results showed that the MREs specimen in mold had successively experienced free compression stage, transition stage and triaxial compression stage during the experiment. The stress-strain curves of the MREs specimen changed when the concentration of magnetic particles increased from 0 to 44.7%, and the strain required to reach the transition stage was reduced. The effect of magnetic flux density on the stress-strain curves of the MREs specimen depended on the concentration of magnetic particles. The measured data obtained at different strain rates revealed maximum changes of 15.7% and 0.096% in volume compression modulus and Poisson ratio, respectively, which occurred under the magnetic flux density of 200 mT and CIP concentrations of [Formula: see text]. In this study, through a set of experiments, the stress-strain curves of the MREs specimen under different concentrations was elucidated, and their effects on the volume compression modulus and Poisson ratio were discussed.

Creation of a Device for Testing of the Rock Samples for Gap in Volumetric Compression Chamber

A device for the volume compression chamber of the samples is described and some possibilities for testing the samples are presented: compressive strength, angle of internal friction, and adhesion values of coal and host rocks. In addition, descriptions of patents for devices allowing to test rocks for breaking during volume compression are given.

Investigating the anisotropic compression and high-pressure phase symmetry of orthorhombic RFeO3 vs RMnO3

Rare-earth orthoferrites and orthomanganites present strong couplings between their structural distortions and physical properties, namely magnetoelectricity, generating interest in predicting and realizing new phases under external parameters, such as hydrostatic pressure. In this regard, we discuss the differences and the similarities of the high-pressure behaviour of the structural distortions arising from anisotropic volume compression. This allows a better understanding of the role played by the octahedra tilt and Jahn-Teller effect as pressure accommodation mechanisms on the stabilization of different crystallographic phases after the insulator to metal structural transition occurring at the critical pressures (Pc) between 35 and 50 GPa.