Spatial Analysis of Gravity Data in the Basement of the Yaoundé-Yoko Area from the Global Gravity Model: Implication on the Sanaga Fault (South-Cameroon)

In this work, gravity anomalies from the XGM2016 global gravity model are used to study the basement of the Yaounde, Yoko area. The aim is to locate the characteristic tectonic faults and to characterize the geometry of the basement of these localities in order to improve the knowledge of the structural and tectonic basement of the study area. Numerical filters (vertical gradient, horizontal gradient, upward continuation) and Euler deconvolution were applied to the gravity anomalies respectively for qualitative and quantitative analysis. The results of the qualitative analysis allowed us to establish the lineament map of the study area;ranging from 0 to 35 km depth. For the quantitative analysis, the work is done in two parts: 1) highlighting the distribution of depths of geological structures in the basement of the study area;2) 2D1/2 modeling of geological structures to highlight the geometry of the basement of Yaounde, Yoko area. Thus, from five suitably selected profiles, the established models reveal the presence of eight blocks of geological structures of different densities and analyze their implications on the Sanaga Fault. Moreover, the models show that the positive anomalies characteristics for the Sanaga Fault reflect the anomalous character due to the strong dominance of the shale intrusion in the basement.

Performance evaluation on field synergy and composite regeneration by coupling cerium-based additive and microwave for a diesel particulate filter

In order to reveal the mechanics of composite regeneration by coupling cerium-based additive and microwave for a diesel particulate filter, a composite regeneration model by coupling cerium-based additive and microwave for a diesel particulate filter was established based on field synergy theory. Performance evaluation on field synergy and composite regeneration of the diesel particulate filter was conducted by using the vortex crushing combustion and field synergy mathematical models. The results show that the peak temperature of the particulate filter body reaches 1180-1190 K when the regeneration time is 175 s, and there are optimal coordination degree between the velocity vector and temperature gradient of the filter body and the maximum ratio0.56-0.60 of the best burning regeneration region is obtained. Accordingly, the largest regeneration combustion rate inside the particulate filter body and the highest regeneration efficiency at the moment are achieved.

High-Speed Numeral Filter in Impulse Voltage Measurement

Since the CPU of embed system has some limitation in operating speed, a new filter was put forward which implemented mountain template convolution by performing rectangle template convolution two times. It can obtain time and frequency localization with computational complexity greatly reduced. This algorithm was applied to lightning waveforms (include chopped waveforms) parameter calculation. It simplifies the computation and the results pretreated by this algorithm are in accord with IEC1083-2 completely. It was applied in embed system successfully. Its capability in frequency restraining was researched. The validity of the algorithm was proved in theory when processing lightning waves. The standard sources and the processing results are consistent completely.

Simulations of vertical jet penetration using a filtered two-fluid model in a gas-solid fluidized bed

The influence of a vertical jet located at the distributor in a cylindrical fluidized bed on the flow behavior of gas and particles was predicted using a filtered two-fluid model proposed by Sundaresan and coworkers. The distributions of volume fraction and the velocity of particles along the lateral direction were investigated for different jet velocities by analyzing the simulated results. The vertical jet penetration lengths at the different gas jet velocities have been obtained and compared with predictions derived from empirical correlations; the predicted air jet penetration length is discussed. Agreement between the numerical simulations and experimental results has been achieved.

Digital holographic shape measurement using Fizeau microscopy

We present a Fizeau interferometer using a microscopic objective as a tool for surface contouring without the need for a numerical lens for reconstruction. The interferometer is associated with a telescope system to feature the object with collimated light. The experiment is conducted on two objects possessing different step heights.The phase maps from the captured off-axis holograms are calculated numerically, which allows us to deduce the contours of the objects. The great advantages of the presented technique are that it can be done in real time and there is no need for numerical lenses for micro-objects reconstruction.