The Lower Llandoverian metasedimentary rocks of the Prades Mountains, southwestern Catalonia, Spain, consist of interstratified anorthite-rich beds, chert beds, phosphate beds, sulfide-rich black shale (with mainly pyrrhotite and minor chalcopyrite), massive sulfide lenses and calc-silicate beds. These metasedimentary rocks are anomalously enriched in V and Cr, and have disseminated minerals of...

Let M̄ be a complex space form of constant holomorphic sectional curvature c and let M be an n-dimensional CR-submanifold of (n− 1) CR-dimension in M̄. ThenM has an almost contact metric structure (F,U ,u,g) (see Section 2) induced from the canonical complex structure of M̄. Hence on an n-dimensional CR-submanifold of (n− 1) CRdimension, we can consider two structures, namely, almost contact struc...

in the present study, an indigenous medicinal plant, tridax procumbens (asteraceae) was used as bioadsorbent for the removal of cr (iii) ions from synthetic wastewater and the method was also applied for real sample analysis. the biosorption of cr (iii) was a two-stage batch reactor process. in the first stage, raw biomaterial was used to the conversion of cr (vi) into cr (iii). the amount of t...

Cr(VI) is considered to be potentially carcinogenic to humans. Removal of Cr(VI) ions from aqueous solution under different conditions was investigated using activated alumina (AA) and activated charcoal (AC) as adsorbents. Batch mode experiments were conducted to study the effects of adsorbent dose, contact time, pH, temperature and initial concentration of Cr(VI). Results showed that the adso...

Controlled release (CR) formulations have generally been considered as follow-ons to conventional immediate release formulations to manage the life cycle of a product. Although significant opportunities exist to use CR as an enabling technology for certain exploratory drug candidates, they have not been fully exploited. However, progress made in assessing CR feasibility based on the physicochem...

Despite the importance of online product recommendations (OPR) in e-Commerce transactions, there is still very little understanding about how different recommendation sources affect consumers' beliefs and behavior, and whether these effects are additive, complementary or rivals for different types of products. This study investigates the differential effects of provider recommendations (PR) and...

Adsorption experiment from aqueous solutions containing known amount of chromium (Cr) using hybrid membrane of chitosan and silicon dioxide was explored to evaluate the efficiency of the membrane as sorbent for Cr(VI). Some variable parameters such as pH, contact time and the dosage of the membrane were optimized. Adsorption isotherms of Cr(VI) onto the hybrid membrane were measured with varyin...