objective(s): so far, extensive research has been conducted on the preparation and characterization of nano ceramics based on ca-si by sol- gel method and bioactivity was evaluated, but, a few researches have paid attention to the preparation of materials by mechanical activation (ma). the aim of this study was the preparation of akermanite nano powder by mechanical activation method and bioact...

fertilization is triggered by changes in intracellular calcium concentration. in mammals, these transients in ooplasmic calcium concentration take the form of repetitive spikes, so called calcium oscillations (ca2+-oscillations). these oscillations are important for relieve of meiotic arrest and to induce all the other events of oocyte activation. although a surface mediated way of oocyte activ...

the objective of the research was to test the effect of iron and aluminium coagulants commonly used for lake re-cultivation, on the pike sperm motility and fertilisation. the coagulants caused changes in the analyzed hydrochemical parameters of the water such as: fe, mg2+, tss, so42- and cl-. selected parameters of sperm motility: mot, vcl, vsl, vap, lin were estimated using casa. the sperm mot...

The commercial profile of the Amoco CD MgCl2 supported polypropylene catalyst is presented. The development, the unique method of preparation/production, with emphasis on particle morphology, and the parameters affecting particle size (PS), particle size distribution (PSD), and particle shape are discussed in detail. The outstanding performance of the catalyst, tailoredmade for the Amoco-Chisso...

the kinetics and mechanism of the reaction between benzaldehyde 1, malononitrile 2 and dimedone 3 in a mixture of ethanol and water as solvents in the presence of fructose as a biodegradable catalyst has been studied by the spectroscopic method (uv-vis spectrophotometry method). the influence of various parameters (temperature, solvent and concentration) was studied on the reaction by means of ...

Electron transfer between the title compounds and their radical cations, which were generated by photoinduced electron transfer from the sulfides to excited 2,4,6-triphenylpyrylium cations, was investigated by time-resolved measurements of chemically induced dynamic nuclear polarization (CIDNP) in acetonitrile. The strongly negative activation entropies provide evidence for an associative-disso...