Directional amine-based solvent extraction for simultaneous enhanced water recovery,salt separation and effective descaling from hypersaline brines

The feasibility of simultaneous water recovery,salt separation and effective descaling of hypersaline brine was investigated by diisopropylamine(DIPA)-based directional solvent extraction(DSE),using diluted/concentrated seawater with initial saline concentration range of 12–237 g/L at extraction temperatures of 5 and 15°C,respectively.The water recovery shows an obvious boundary at saline concentration of 115 g/L under dual effect of specific water extraction efficiency and extraction cycles.High Cl–ion concentration in product water is in sharp contrast to the nearly complete removal of SO_(4)^(2–)and hardness ions,indicating that DIPA-based DSE process indeed achieved efficient separation and purification of Cl–ion from hypersaline brines.Especially,the radical precipitation of Mg^(2+)and Ca^(2+)ions in form of Mg(OH)_(2)and CaCO_(3)demonstrates effective descaling potential,although it leads to more DIPA residues in dewatered raffinate than product water.Moreover,an exponential correlation between the Cl–removal efficiency and specific water extraction efficiency further reveals the intrinsic relationship of water extraction process and transfer of Cl–ion to the product water.Overall,the study provides a novel approach for integrating the water recovery and separation of Cl–ion from ultra-high-salinity brines with radical precipitation of Mg^(2+)and Ca2+ions in one step.

Modeling and parameter extraction of CMOS on-chip coplanar waveguides up to 67 GHz for mm-wave applications

Coplanar waveguides （CPW） are widely used in mm-wave circuits designs for their good performance. A novel unified model of various on chip CPWs for mm-wave application, together with corresponding direct parameter extraction methodologies, are proposed and investigated, where standard CPW, grounded CPW （GCPW） and CPW with slotted shield （SCPW） are included. Several kinds of influences of different structures are analyzed and considered into the model to explain the frequency-dependent per-unit-length L, C, R, and G parameters, among which the electromagnetic coupling for CPWs with large lower ground or shield is described by a new C-L-R series path in the parallel branch. The direct extraction procedures are established, which can ensure both accuracy and simplicity compared with other reported methods. Different CPWs are fabricated and measured on 90-nm CMOS processes with Short-Open-Load-Through （SOLT） de-embedding techniques. Excellent agreement between the model and the measured data for different CPWs is achieved up to 67 GHz.