A study has been conducted on the synthesis of paramagnetic mercapto silica hybrids as metal adsorbent of Ag(I). The aim of this study was to synthesis paramagnetic mercapto silica hybrid from rice husk ash waste, knowing the characteristics of paramagnetic mercapto silica hybrid from rice husk ash waste, and to determine the effect of pH, metal ions concentration, and the contact time on the value of adsorption capacity (Q). Based on the results of the study, it was found that paramagnetic mercapto silica hybrids can be synthesized from the rice husk ash waste. Characterization using FTIR spectroscopy showed that silanol (Si-OH), siloxan (Si-O-Si), -SH, and Fe-OH functional groups, and characterization of paramagnetic mercapto silica hybrid structures using XRD to show crystalline compounds with a position value of 2θ = 35.4 which showed that the magnetite material of Fe3O4 was coated by silica. Paramagnetic mercapto silica hybrids from rice husk waste can be used as adsorbent of Ag (I) metal at optimum conditions of pH 3, contact time of 120 minutes, and adsorption capacity of 392.01 mg/g. The suitable isotherm model is the Freundlich isotherm model which means the absorption of metal Ag (I) occurs physically, while adsorption of kinetics followed the pseudo II order kinetic model with a value of k  = 3.01 g.mg-1 minute-1.

The rapidly growing demand for petroleum resources has become a crucial global problem. Therefore, a more realistic solution is required for oil production. Enhanced oil recovery (EOR) has become an essential technique to extract original oil content and maintain oil fields. During this process, certain viscous polymers are commonly used as mobility control agents. In this work, we introduce a new class of polymer to address the limitations of commercial EOR polymers. We successfully extracted kappa-type carrageenan from Eucheuma cottonii seaweed using demineralized water and ethanol precipitation. The amount of yield, intrinsic viscosity, and viscosity-average molecular mass of the extracted carrageenan were 18.64%, 12.77 dLg -1 , and 4.716×10 5 gmol -1 , respectively. Characterizations were done by dynamic viscosity and rheological measurement, along with a thermal degradation test. The measurements indicated that kappa-carrageenan is an attractive green substitute for polyacrylamide, as it showed relatively high resistance to temperature, shear rate, and salinity compared to polyacrylamidebased commercial EOR polymers. However, a higher concentration of carrageenan is still needed to reach the same viscosity as the commercial polymers.

Eugenol and its new or known derivatives were prepared through varies reactions and screened by in vitro model of antibacterial activities using pathogen bacteria: Eschericia coli, Bacillus cereus, and Staphylococcus aureus. Nearly all compounds showed antibacterial activities. The obtained results demonstrate that eugenol was still significantly more active than its derivatives, with inhibition (14-18) mm, suggesting that this chemical transformation failed to increase antibacterial activities of eugenol. The presence of nitro, cyclic sulfonic ester, N-dimethyl, quinoline, amino, isocyanate, amide and ester moieties has no ability to enhance the antibacterial activities of eugenol.

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