Carbide Nanoparticle Dispersion Techniques for Metal Powder Metallurgy

Nanoparticles (NP) embedded into a matrix material have been shown to improve mechanical properties such as strength, hardness, and wear-resistance. However, the tendency of NPs to agglomerate in the powder mixing process is a major concern. This study investigates five different mechanochemical processing (MCP) routes to mitigate agglomeration to achieve a uniform dispersion of ZrC NPs in an Fe-based metal matrix composite. Our results suggest that MCP with only process controlling agents is ineffective in avoiding aggregation of these NPs. Instead, the uniformity of the carbide NP dispersion is achieved by pre-dispersing the NPs under ultrasonication using suitable surfactants followed by mechanically mixing of the NPs with iron powders in an alcohol solvent which is then dried. High-energy MCP is then used to embed the NPs within the powders. These collective steps resulted in a uniform dispersion of ZrC in the sintered (consolidated) Fe sample.

Efficacy of solid dispersion of fenbendazole against gastrointestinal strongylatosis of young cattle

The purpose of the research is to study the efficacy of solid dispersion of fenbendazole (SDF) against nematodoses of young cattle.Materials and methods. The study of SDF, obtained by mechanochemical processing of fenbendazole substance with polyvinylpyrrolidone (PVP) polymer, was carried out on 126 young cattle naturally infected with nematodiroses and other gastrointestinal strongylatoses. The animals were divided into 6 experimental groups of 10–11 animals each and SDF was administered once orally at doses of 2.0; 3.0 and 4.0 mg/kg of active substance (a.s.) (I-III groups) in comparison with the mechanical mixture of fenbendazole (FBZ) and PVP in a ratio of 1:9 (IV group) and substance FBZ at a dose of 3.0 mg/kg (group V) against each helminthosis. The control group of animals did not receive the drugs. Anthelmintic efficacy was evaluated in the "control test" based on the data of ovoscopic examination of feces of young cattle by flotation method before and 17 days after drugs administration.Results and discussion. SDF with PVP at a dose of 2.0; 3.0 and 4.0 mg/kg of a.s. in the form of a 10% powder showed respectively 88.4; 97.3 and 100% efficiency at nematodiroses and 89.2; 98.4 and 99.5 % activity against other types of gastrointestinal strongylates upon obtaining 32.3 and 32.4 % effect of the mechanical mixture of FBZ with PVP and 29.7 and 27.4% efficiency of the base preparation at a dose of 3.0 mg/kg. SDF showed 88.4; 97.3 and 100% of efficacy at doses of 2.0; 3.0 and 4.0 mg/kg of a.s., respectively, against nematodiroses and 89.2; 98.4 and 99.5% against other gastrointestinal strongylatoses in the form of 10% powder. It should be noted that mechanical mixture of PBZ with PVP showed 32.3 and 32.4% efficacy and the efficacy of the basic drug was 29.7 and 27.4% at a dose of 3.0 mg/kg against each helminthosis.