field study was conducted at five villages of Botswana namely, Tsabong, Tshane, Mathathane, Motlhabaneng and Tsetsejwe during the periods of June to August 1999 and June to August 2000. The objective of the study was to assess and compare the soil physicochemical properties of soils at the five villages and to study the effect of cultivation on some soil physical properties. Parameters measured...

In this study, TiO2 and ZnO nanofilms were prepared by sol-gel spin-coating method. Nanofilms were characterized by X-ray Diffraction (XRD), Energy Dispersive Analysis of      X-ray (EDX), Scanning Electron Microscopy (SEM) and Field Emission Scanning Electron Microscopy (FE-ESM). Structural and morphological properties of nanofilms were investigated. The average crystalline size of ...

Electrospinning has been recognized as an efficient technique for the fabrication of polymernanofibers. Recently, various polymers have successfully been electrospun into ultrafine fibers.Electrospinning is an extremely promising method for the preparation of tissue engineering scaffolds.In this study, nanofibers gelatin was electrospun at 20% v/v optimized content. To produce...

In this study, TiO2 and ZnO nanofilms were prepared by sol-gel spin-coating method. Nanofilms were characterized by X-ray Diffraction (XRD), Energy Dispersive Analysis of      X-ray (EDX), Scanning Electron Microscopy (SEM) and Field Emission Scanning Electron Microscopy (FE-ESM). Structural and morphological properties of nanofilms were investigated. The average crystalline size of ...

In this article, the effect of hygrothermal aging on mechanical properties of fiber metal laminates (FMLs) and E-glass/epoxy (GE) composites is investigated. First, FML and GE specimens were built using wet lay-up technique under vacuum pressure. Hygrothermal aging simulation was then carried out on both specimen types in distilled water at a constant temperature of 90 °C for 5 weeks. The resul...

We study a semiparametric pseudo-likelihood inference for nonhomogeneous Gamma process with random effects for degradation data. The setting for degradation data is one in which n independent subjects, each with a nonhomogeneous Gamma process, are observed at possible different times. The random effects are used to represent heterogeneity of degradation paths. To obtain the maximum pseudo-likel...

This study investigates the in vitro degradation properties of composites consisting of a porous tricalcium phosphate (TCP) foam filled with degradable poly(dl-lactic acid) (PDLLA) via either in situ polymerization or infiltration. The motivation was to develop a material for bone repair that would be initially mechanically strong and would develop porosity during degradation of one of the comp...

Porous hydrogels of poly(ethylene glycol) (PEG) have been shown to facilitate vascularized tissue formation. However, PEG hydrogels exhibit limited degradation under physiological conditions which hinders their ultimate applicability for tissue engineering therapies. Introduction of poly(L-lactic acid) (PLLA) chains into the PEG backbone results in copolymers that exhibit degradation via hydrol...

A fourth-generation Ziegler-Natta catalyst was prepared to synthesize polypropylene (PP), which was stabilized by in situpolymerization employing lignin as antioxidant. The antioxidant properties of lignin were compared with those of the commercial antioxidant Irganox 1010. The presence of lignin in the reaction medium slightly decreased the catalytic activity of the reaction. The isotacticity ...