Effect of Free-fall Nozzle Channel Dispersion Angle on TC4 Discontinuous Droplets Pre-breakup in EIGA

The effect of the inlet gas pressure,supplementary gas pressure and nozzle channel dispersion angle on the pre-breakup behavior of Ti-6Al-4V(TC4)discontinuous droplets during EIGA was investigated by combining numerical simulation with experiments.The results show that the axial velocity at the recirculation zone before the stagnation location was first increased and decreased then increased significantly after the peak value,while the pressure of the recirculation zone increased with the increase in inlet pressure.With the supplementary pressure increasing,the velocity magnitude and range of the recirculation zone gradually decreased.As the dispersion angle of the nozzle channel increased,the pre-breakup efficiency of droplets gradually decreased,but the adhesion phenomenon of droplets on the inner wall surface of the nozzle channel(IWSNC)gradually weakened.Under the inlet pressure of 4 MPa,a supplementary pressure of 0.05 MPa,and the dispersion angle of 15°,the uniform and spherical TC4 powders with diameter of 70μm were prepared,which was consistent with the simulation results.The optimized process parameters is a balance between the size of the pre-atomized particles and the back-spraying and bonding phenomenons of droplets.

Range formula based on angle of dispersion and nozzle configuration from an impact sprinkler

Jet breakup and dispersion from impact sprinkler are mainly influenced by the configurations of nozzle and dispersion device.Based on the structure,different types of nozzles were designed and tested with a pointed tip dispersion device under low pressure conditions.Experiments were performed using High-Speed Photographic technique,and Matlab computation program was established and applied to determine the initial jet breakup length and angle of dispersion from the nozzles.The sprinkler range decreased with the increase in diameter of nozzle,and the largest range of 15.1 m was produced from sprinkler with 6 mm nozzle size under a pressure of 150 kPa.The angle of dispersion decreased with the increase of jet velocity,the spray coverage from sprinkler with 6 mm nozzle size was 1478 mm under 150 kPa,and was not statistically different when the pressure was increased.A new range formula was established for sprinkler with dispersion device through curve fitting of the parameters of initial jet breakup length,angle of dispersion,nozzle size and working pressure.The new formula was reliable for calculating range with a relative error less than 3%.Since the formula is based on the angle of dispersion,it could be useful to estimate uniformity of water distribution in sprinkler irrigated fields.

Accurate prediction of protein dihedral angles through conditional random field

Identifying local conformational changes induced by subtle differences on amino acid sequences is critical in exploring the functional variations of the proteins. In this study, we designed a computational scheme to predict the dihedral angle variations for different amino acid sequences by using conditional random field. This computational tool achieved an accuracy of 87% and 84% in 10-fold cross validation in a large data set for φ and ψ, respectively. The prediction accuracies of φand ψ are positively correlated to each other for most of the 20 types of amino acids. Helical amino acids can achieve higher prediction accuracy in general, while amino acids in beet sheet have higher accuracy at specific angular regions. The prediction accuracy of φ is negatively correlated with amino acid flexibility represented by Vihinen Index. The prediction accuracy of φ can also be negatively correlated with angle distribution dispersion.

Influence of Uneven Trace Spacing on Rayleigh Wave Dispersion

Rayleigh wave dispersion signals are significant to underground investigation.Tradition-ally,uniformed trace spacing is employed in surface wave surveys.In some cases,however,uneven trace spacing is often encountered because of the limitations of the site condition.In order to study the influence of uneven trace spacing on the dispersion data construction of Rayleigh waves,data acquisi-tion is performed based on a 2.5D field layout with a linear array of geophones fixed and a mobile source.The observation direction controls the trace spacing of the measurement.The final results demonstrate that the trace nonuniformity has significant influence on the Rayleigh wave dispersion feature constructed.When the observation angle is over 45o,the dispersion image will be too distorted to extract dispersion data correctly.