Some results of seismic travel-time reflection tomography study

Velocity model is essential for seismic data processing as it plays an important role in migration processes as well as time depth conversion. There are several techniques to reach that goal, among which tomographic inversion is an efficient one. As an upgrade version of handpicked velocity analysis, the tomography technique is based on the reflection ray tracing and conjugate gradient method to estimate an optimum velocity model and can create an initial high quality model for other intensive imaging and modelling module such as reverse-time migration (RTM) and full-waveform inversion (FWI). For the mentioned benefit, we develop a seismic travel-time reflection tomography (SeisT) module to study the accuracy of the approach along with building the technical capability in seismic processing. The accuracy of the module has been tested by both synthetic and real seismic field data; the efficiency and the accuracy of the model have been proven in terms of development method as well as field data application.

Experimental and Computational Investigation of Integrated Internal and Film Cooling Designs Incorporating a Thermal Barrier Coating

Few studies in the open literature have studied the effect of thermal barrier coatings when used in combination with shaped hole film cooling and enhanced internal cooling techniques. The current study presents RANS conjugate heat transfer simulations that identify trends in cooling design performance as well as experimental measurements of overall effectiveness using a flat-plate matched-Biot number model with a simulated TBC layer of 0.42D thickness, where D is the film cooling hole diameter. Coolant is fed to the film cooling holes in a co-flow configuration, and the results of both smooth and rib-turbulated channels are compared. At a constant coolant flow rate, enhanced internal cooling was found to provide a 44% increase in spatially-averaged overall effectiveness, ϕ ̿ , without a TBC. The results show that the addition of a TBC can raise ϕ ̿ on a film-cooled component surface by 47%. The optimum velocity ratio was found to decrease with the addition of enhanced cooling techniques and a TBC as the film provided minimal benefit at the expense of reduced internal cooling. While the computational results closely identified trends in overall system performance without a TBC, the model over-predicted effectiveness on the metal-TBC interface. The results of this study will inform turbine component design as material science advances increase the reliability of TBC.

Online optimum velocity calculation under V2X for smart new energy vehicles

In this paper, a vector data net solver is proposed, which can reduce bivariate discrete-time dynamic programming (DP) computation time by 98.0% without losing accuracy. Therefore, for the first time, bivariate discrete-time DP can operate under model predictive control rolling optimization to calculate future optimum vehicle velocity in real time considering future road altitude and instant traffic information. Simulation results indicate that with the solution presented in this paper, front vehicles and the proper windows to pass through front intersections can be constantly considered. Meanwhile, the calculated optimum vehicle velocity almost remains the same as the global optimum solutions. Simulation results are validated by real-car tests, and the test new energy vehicle (NEV) electricity consumption is reduced by up to 48.6%. A comparison experiment is performed between the solution presented in this paper and commonly used adaptive dynamic programming (ADP), and the results indicate that the former has better performance and stability. This paper describes a novel solution for online optimum velocity calculation under vehicle to everything (V2X) environment and can be used by all smart NEVs with autonomous driving or active cruise control functions for lower electricity consumption and better riding comfort.

Novel helical or coiled flocculator for turbidity reduction in drinking water treatment: a performance study

The study was divided into two steps: Jar test to determine the optimum dose of coagulant and flocculation experiments to evaluate the helical flocculator efficiency. Efficiencies were in the range of medium to high. On flowrate 13 ml/second was obtained good results for two pipe sizes but different in helical diameters. In 0.5 inch pipe with 0.8 m helical diameter the turbidity reduction efficiencies were 72.4% and 73.9% and sediment volume were 18.3 ml and 20.0 ml. In 0.625 inch pipe with 0.4 m helical diameter the turbidity reduction efficiencies were 76.7% and 78.5% and sediment volume were 14.3 ml and 19.7 ml. The optimum velocity gradient about 64.9–69.6 persecond and detention time about 438–649 seconds. The results showed that helical flocculator was effective for floc formation. Flowrate, pipe diameter, helical diameter were three key parameters to perform helical flocculator.

Optimization of Plunger Injection Input for Die Casting Process

Die casting is adequate for mass production and has the advantage of being able to yield a complicated shape accurately. However, casting defects caused by plunger movement remain a problem. Velocity control of the plunger is very effective to avoid casting defects. Velocity control input is manually conducted by skilled workers because the analysis of molten metal is very difficult, and injection molding is performed at places in the mold where it is invisible. In this paper, Quid behavior and the amount of air entrainment caused by the movement of the die casting plunger are analyzed using computational Quid dynamics (CFD). The optimum velocity control input of the die casting plunger was calculated in order to reduce air entrainment and molten metal forerunning to prevent the occurrence of defects in the die casting product. Optimization was performed by a Genetic algorithm incorporating CFD simulator.

Sprint acceleration mechanical profiling of international cricketers

Sprinting and speed is a fundamental skill and physical attribute crucial in seam bowlers and batters within cricket. The aim of this study was to assess differences in mechanical properties during sprinting between youth and senior international cricketers and between seam bowlers and batters. Retrospective 40 m sprint times and anthropometric measures of 56 international cricketers (19 senior seam bowlers, 7 under-19 seam bowlers, 16 senior batters, 14 under-19 batters) were used to calculate the theoretical maximal force (F0), theoretical maximal velocity (V(0)), theoretical maximal power (Pmax), slope of the force-velocity relationship (F-V slope), maximal ratio of horizontal-to-resultant force (RFmax), decrease in the ratio of horizontal-to-resultant force (DRF) and optimum velocity (Vopt). There were no significant (P > 0.05) differences in sprint times nor sprint mechanical profile variables between position or age. However, there was a moderately greater F0 (N/Kg) (ES = 0.78; 90% CI 0.19–1.34) and RFmax (ES = 0.75; 90% CI 0.11–1.35) in senior seam bowlers when compared to batters. Furthermore, FV Slope (ES = 0.79; 90% CI 0.15–1.40) and DRF (ES = 0.75; 90% CI 0.11–1.35) were moderately greater in senior compared to under-19 batters. When expressed relative to body mass, it appears that senior international seam bowlers show trends towards a more force biased profile during sprinting when compared to batters. These findings will help coaches to optimise physical preparation strategies in youth and senior international cricketers.