Asymptotically almost periodic distributions

In this work we extend to the space of Schwartz' distributions the notion of asymptotic almost periodicity of M. Frechet. The main justification for the introduction of this concept is the fact that for certain differential equations in distributions the existence of an asymptotic almost periodic (distribution) solution implies the existence of an almost periodic (distribution) solution, as an example shows     

Investigation of chemical mechanical polishing of zinc oxide thin films

Zinc oxide has become an important material for various applications. Commercially available zinc oxide single crystals and as-grown zinc oxide thin films have high surface roughness which has detrimental effects on the growth of subsequent layers and device performance. A chemical mechanical polishing (CMP) process was developed for the polishing of zinc oxide polycrystalline thin films. Highly smooth surfaces with RMS roughness <6 Å (as compared to the initial roughness of 26 ± 6 Å) were obtained under optimized conditions with removal rates as high as 670 Å/min. Effects of various CMP parameters on removal rate and surface roughness were evaluated. The role of pH on the polishing characteristics was investigated in detail.     

Removal of uranyl ions from UO2(NO3)2 solution by means of Chlorella vulgaris and Dunaliella salina algae

This paper deals with a study of the biosorption of UO₂ ²⁺ ions on two green algae: Chlorella vulgaris and Dunaliella salina. By investigating the retention degree versus contact time from Langmuir and Freundlich biosorption isotherms, kinetic investigations and FTIR spectra it was found that the biosorption process was greater for Chlorella vulgaris than for Dunaliella salina. A new kinetics method is proposed to establish the reaction order concerning the biosorption process of uranyl ions on these biomasses.      

Secondary poly(propylene) from used accumulators reused as raw material

A reuse process, as raw material, of secondary poly(propylene) from used accumulators, is presented. The importance of solving the scientific aspects, concerning the influence of residual impurities and those resulted from ageing, on properties of regenerated polymers, in certifying the reliability of reusing the secondary polymers as a raw material, is underlined.