ENVIRONMENTAL AND HYDRAULIC MONITORING USING CATIONIC DYES TO INVESTIGATE THE BARRIERS EFFECT ON KAOLIN DEPOSITION

Dyes are used in hydraulic fields such as hydraulic tracking to show the flow path, monitor flow lines within a ground dam, or track the spread of contaminated water within horizontal pipes and environmental fields as environmental indicators in titrations, such as titration of precipitate composition. Some environmental experiments dispense with the dye's use because it interferes with other compounds, such as interfering with the turbidity readings even if non-reactive dyes, but the present study transformed this problem into a positive phenomenon to benefits from the dye in both fields. The research methodology includes a laboratory analysis using different parameters such as discharge of suspension, the volume of dye, and the percentage of initial water depth at maximum water depth also theoretical analysis of the previous research methodology. The experimental results show that cationic dyes' absorption (methylene blue dye, MB and crystal violet, CV) is directly proportional to the percentage of kaolin deposition in the sedimentation tank areas. Finally, MB and CV dyes are used in both fields in one trial(such as tracking flow movement, monitoring the vortices formed using baffles, and inter between the amount of kaolin precipitated in each zone the sedimentation). However, MB is the best compare to CV.

Langer–Schwartz–Kampmann–Wagner precipitation simulations: assessment of models and materials design application for Cu precipitation in PH stainless steels

Quantitative modelling of precipitation kinetics can play an important role in a computational material design framework where, for example, optimization of alloying can become more efficient if it is computationally driven. Precipitation hardening (PH) stainless steels is one example where precipitation strengthening is vital to achieve optimum properties. The Langer–Schwartz–Kampmann–Wagner (LSKW) approach for modelling of precipitation has shown good results for different alloy systems, but the specific models and assumptions applied are critical. In the present work, we thus apply two state-of-the-art LSKW tools to evaluate the different treatments of nucleation and growth. The precipitation modelling is assessed with respect to experimental results for Cu precipitation in PH stainless steels. The LSKW modelling is able to predict the precipitation during ageing in good quantitative agreement with experimental results if the nucleation model allows for nucleation of precipitates with a composition far from the equilibrium and if a composition-dependent interfacial energy is considered. The modelling can also accurately predict trends with respect to alloy composition and ageing temperature found in the experimental data. For materials design purposes, it is though proposed that the modelling is calibrated by measurements of precipitate composition and fraction in key experiments prior to application. Graphic abstract

Thermodynamic Analysis of Ti3O5Nanoparticles Formed in Melt and Their Effects on Ferritic Steel Microstructure

Based on the Wagner’s formalism combined with mass conservation, a thermodynamic analysis method has been developed previously. This method enables the calculation of the equilibrium matrix composition, precipitate composition and precipitate total molar fraction for TixOy(s) in molten metal, which can be determined at any appropriate temperature. In this present study, the Ti3O5 phase precipitation and the quantitative relationship between the addition of Ti, O and Ti3O5 in the molten steel were studied using the thermodynamic model. Using the combined multipoint dispersion supply method, electromagnetic stirring and well-dispersed 5-nm Ti3O5 nanoparticles were fabricated in the ferrite matrix of the as-cast high-strength steel with 0.05 wt % Ti—0.002 wt % O. The as-cast microstructure was improved by the homogeneously dispersed Ti3O5 nanoparticles through heterogeneous nucleation and grain refinement.

Superfast Set, Strong and Less Degradable Mineral Trioxide Aggregate Cement

Purpose. Despite the good sealing ability and biocompatibility of mineral trioxide aggregate (MTA), its slow setting, high degradation, and weakness limit its use in surgical endodontics and high stress-bearing areas. This study aimed to develop two new liquids to control these drawbacks. They were prepared from calcium chloride, fumed silica, and hydroxyapatite or calcium phosphate and coded “H” and “P,” respectively. Methods. Portland cement, Grey ProRoot® MTA, and white ProRoot MTA were mixed with distilled water (control) or liquid “H” or “P.” The pH, setting time, degradation rate, leachant/precipitate’ composition, compressive strength, and morphology were assessed. Results. Both liquids maintained MTA’s high alkalinity and reduced the setting time by 1-2 orders of magnitude. Both liquids, H in particular, significantly reduced the degradation rate of Grey ProRoot and White ProRoot MTA®. Calcite has been identified as the main phase of the leachant or precipitate formed during the cement’s degradation. Calcium hydroxide or hydroxyapatite was also identified with Grey ProRoot MTA mixed with H liquid. These liquids also significantly increased the compressive strength with no statistical differences between them; this was associated with the production of dense, consolidated structures. Conclusions. The modified MTA could be used in surgical endodontics and high stress-bearing areas.

The Study on the Precipitation Behavior of the Second Phase Particles for Fine Grain and High Strength IF Steel

The new type SFG HSS (super fine grain, high strength steel sheet) has been developed by adding solid-solution strengthening elements to conventional IF steel such as Si, Mn. The precipitation behavior of the second phase particles was observed and studied by a carbon extraction replica technique used transmission electron microscopy (TEM). The shape of the small second particles is similar to spherical and ellipse, the sizes of which are 10~30nm. It is seen that the particles are dispersed on the matrix. The precipitate composition of small particles is Nb (CN) and the precipitate composition of large particles is NbC examined by energy dispersive X-ray (EDX). It is noted that the yield strength is low as well as the tensile strength is high by the PFZ which is free of precipitate called precipitated free zone on the one side of the grain boundary. The results of microstructure shows that the second phase particles pinned on grain boundary not only can inhibit the grain growth, but also the grain can be fined.