We combine density-functional theory with the string method to calculate the minimum free energy path of bubble nucleation in two polymer–CO2 mixture systems, poly(methyl methacrylate) (PMMA)–CO2 and polystyrene (PS)–CO2. Nucleation is initiated by saturating the polymer liquid with high pressure CO2 and subsequently reducing the pressure to ambient condition. Below a critical temperature (Tc),...

As a natural refrigerant, CO2 gets more and more attention in recent years. The CO2 system runs at a trans-critical cycle. This leads to a high running pressure and high pressure difference for the CO2 compressor. In this paper the single stage and two stage rolling piston compressors with same displacement have been developed for CO2 heat pump water heater. And a comprehensive performance comp...

Reliable inventory information is critical in informing emission mitigation efforts. Using the latest officially released emission data, which is production based, we take a consumption perspective to estimate the non-CO2 greenhouse gas (GHG) emissions for China in 2012. The non-CO2 GHG emissions, which cover CH4, N2O, HFCs, PFCs, and SF6, amounted to 2003.0 Mt. CO2-eq (including 1871.9 Mt. CO2...

In this work, the cholesterol concentration in the supercritical (SC) CO2, under working conditions, is calculated by implementing the modified Peng Robinson equation of state (EoS) combined with the Van Der Waals mixing rules. Here, optimisations of the interaction coefficient (kij) between solvent and solute and the solute critical parameters (i.e. critical pressure and temperature) are the m...

The effect of carbon dioxide (CO2) sorption on the lower critical solution temperatures of deuterated polybutadiene/polyisoprene blends was determined with in situ small-angle neutron scattering. CO2 was a poor solvent for both polymers and exhibited very weak selectivity between the blend components. The sorption of modest concentrations of CO2, at pressures up to 160 bar, induced phase segreg...

Storage of anthropogenic CO2 in geological formations relies on a caprock as the primary seal preventing buoyant super-critical CO2 escaping. Although natural CO2 reservoirs demonstrate that CO2 may be stored safely for millions of years, uncertainty remains in predicting how caprocks will react with CO2-bearing brines. This uncertainty poses a significant challenge to the risk assessment of ge...

Background. Bilateral severe obstruction of the internal carotid artery is a hemodynamically critical state. We aimed to (1) analyze dynamic cerebral autoregulation (DCA) in affected patients, and (2) to correlate DCA data with different collateral flow patterns. Methods. DCA was assessed noninvasively by transfer function analysis (phase shift) of respiratory induced oscillations at 0.1 Hz of ...

OBJECTIVE We investigated the effect of immersion of feet in CO2-enriched water for preventing expansion and formation of ischemic ulcer in critical limb ischemia of diabetic patients after surgical revascularization. MATERIALS AND METHODS Eligible patients were allocated CO2 group (CO2 immersion plus standard care) or control group (standard care alone) and were followed up for 3 months afte...