Enhanced Olivine Reactivity in Wet Supercritical CO for Engineered Mineral Carbon Sequestration.

The success of CO mineralization as a potential solution for reducing carbon emissions hinges on understanding chemical interactions between basaltic minerals and CO-charged fluids. This study provides a detailed analysis of olivine dissolution in CO-water mixtures at 90 and 150 °C, 2-9 MPa, and for 8 and 24 h, in both water- and CO-dominant conditions. By using olivine crystal sections instead of powders, surface agitation is prevented, closing the gap between laboratory studies and natural settings.

Speed of Sound Measurements in Helium at Pressures from 15 to 100 MPa and Temperatures from 273 to 373 K.

The speed of sound in helium was measured along five isotherms in a temperature range from 273 to 373 K at pressures from 15 to 100 MPa with a relative expanded uncertainty ( = 2) from 0.02 to 0.04%.

D-dimers in omicron versus delta: A retrospective analysis.

Background: Infection with SARS-CoV-2 has shown to cause an increase in D-dimers, which correlate with severity and prognosis for in-hospital mortality. The B.1.

Electroreduction of CO/CO to C Products: Process Modeling, Downstream Separation, System Integration, and Economic Analysis.

Direct electrochemical reduction of CO to C products such as ethylene is more efficient in alkaline media, but it suffers from parasitic loss of reactants due to (bi)carbonate formation. A two-step process where the CO is first electrochemically reduced to CO and subsequently converted to desired C products has the potential to overcome the limitations posed by direct CO electroreduction. In this study, we investigated the technical and economic feasibility of the direct and indirect CO conversion routes to C products.

Shoulder Pain Diagnosis, Treatment and Referral Guidelines for Primary, Community and Intermediate Care.

These care pathway guidelines for the shoulder have been written in collaboration with the NHS Evidence Based Interventions (EBI) programme. The EBI programme is a partnership between the Academy of Medical Royal Colleges, NHS Clinical Commissioners, the National Institute for Health and Care Excellence, as well as NHS England and Improvement.

Reference Materials for Phase Equilibrium Studies. 1. Liquid-Liquid Equilibria (IUPAC Technical Report).

This article is the first of three projected IUPAC Technical Reports resulting from IUPAC Project 2011-037-2-100 (Reference Materials for Phase Equilibrium Studies). The goal of that project was to select reference systems with critically evaluated property values for the validation of instruments and techniques used in phase equilibrium studies for mixtures. This Report proposes seven systems for liquid-liquid equilibrium studies, covering the four most common categories of binary mixtures: aqueous systems of moderate solubility, non-aqueous systems, systems with low solubility, and systems with ionic liquids.

Residual entropy model for predicting the viscosities of dense fluid mixtures.

In this work, we have investigated the mono-variant relationship between the reduced viscosity and residual entropy in pure fluids and in binary mixtures of hydrocarbons and hydrocarbons with dissolved carbon dioxide. The mixtures considered were octane + dodecane, decane + carbon dioxide, and 1,3-dimethylbenzene (m-xylene) + carbon dioxide. The reduced viscosity was calculated according to the definition of Bell, while the residual entropy was calculated from accurate multi-parameter Helmholtz-energy equations of state and, for mixtures, the multi-fluid Helmholtz energy approximation.

High Pressure Electrochemical Reduction of CO to Formic Acid/Formate: A Comparison between Bipolar Membranes and Cation Exchange Membranes.

A high pressure semicontinuous batch electrolyzer is used to convert CO to formic acid/formate on a tin-based cathode using bipolar membranes (BPMs) and cation exchange membranes (CEMs). The effects of CO pressure up to 50 bar, electrolyte concentration, flow rate, cell potential, and the two types of membranes on the current density (CD) and Faraday efficiency (FE) for formic acid/formate are investigated. Increasing the CO pressure yields a high FE up to 90% at a cell potential of 3.

Thermophysical Properties and Phase Behavior of Fluids for Application in Carbon Capture and Storage Processes.

Phase behavior and thermophysical properties of mixtures of carbon dioxide with various other substances are very important for the design and operation of carbon capture and storage (CCS) processes. The available empirical data are reviewed, together with some models for the calculation of these properties. The systems considered in detail are, first, mixtures of carbon dioxide, water, and salts; second, carbon dioxide-rich nonelectrolyte mixtures; and third, mixtures of carbon dioxide with water and amines.

Atomistic Molecular Dynamics Simulations of Carbon Dioxide Diffusivity in n-Hexane, n-Decane, n-Hexadecane, Cyclohexane, and Squalane.

Atomistic molecular dynamics simulations were carried out to obtain the diffusion coefficients of CO in n-hexane, n-decane, n-hexadecane, cyclohexane, and squalane at temperatures up to 423.15 K and pressures up to 65 MPa. Three popular models were used for the representation of hydrocarbons: the united atom TraPPE (TraPPE-UA), the all-atom OPLS, and an optimized version of OPLS, namely, L-OPLS.

Kinetics of carbonate mineral dissolution in CO-acidified brines at storage reservoir conditions.

We report experimental measurements of the dissolution rate of several carbonate minerals in CO-saturated water or brine at temperatures between 323 K and 373 K and at pressures up to 15 MPa. The dissolution kinetics of pure calcite were studied in CO-saturated NaCl brines with molalities of up to 5 mol kg. The results of these experiments were found to depend only weakly on the brine molality and to conform reasonably well with a kinetic model involving two parallel first-order reactions: one involving reactions with protons and the other involving reaction with carbonic acid.

Experimental and modeling study of the phase behavior of (methane + CO2 + water) mixtures.

In this work we report phase equilibrium measurements on the system (methane + carbon dioxide + water) carried out with a high-pressure quasi-static-analytical apparatus. The measurements have been made under conditions of two-phase vapor-liquid equilibrium, three-phase vapor-liquid-liquid equilibrium (VLLE), and four-phase vapor-liquid-liquid-hydrate equilibrium. The compositions of three coexisting fluid phases have been obtained along eight isotherms at temperatures from (285.

Physical apparatus parameters and model for vibrating tube densimeters at pressures to 140 MPa and temperatures to 473 K.

Vibrating tube densimeters are well-established tools for measuring fluid densities precisely at elevated temperatures and pressures. However, the conventional method of calibrating them utilises a model in which the apparatus parameters are represented as polynomials of temperature and pressure that contain a variable number of terms. Here a robust, physically-based model is presented and demonstrated for six different instruments at temperatures from (273 to 473) K, pressures from (0 to 140) MPa, and densities from (0 to 1050) kg m(-3).

Molecular dynamics simulations of CO2 and brine interfacial tension at high temperatures and pressures.

Molecular dynamics simulations have been performed to study the interfacial tension of CO2 and brine for a range of temperatures between 303 and 393 K and pressures from 2 to 50 MPa. The ions involved in this study are Na(+), Ca(2+), and Cl(-). The results indicate that the interfacial tension decreases with increasing pressure under any temperature condition but increases linearly with the molality of the salt solution.

The effect of pH, dilution, and temperature on the viscosity of ocular lubricants--shift in rheological parameters and potential clinical significance.

Objective: To investigate the effect of temperature, dilution, and pH on the viscosity of ocular lubricants.

Design: Laboratory based investigation of viscosity.

Participants: No human subjects.

The speed of sound and derived thermodynamic properties of pure water at temperatures between (253 and 473) K and at pressures up to 400 MPa.

The speed of sound in high-purity water has been measured in the temperature range (253 to 473) K at pressures up to 400 MPa. The experimental technique used was based on a double-path pulse-echo method with a single 5-MHz ultrasound transducer placed between two unequally spaced reflectors. The cell was calibrated in water at T = 298.

Experimental and molecular modeling study of the three-phase behavior of (n-decane + carbon dioxide + water) at reservoir conditions.

Knowledge of the phase behavior of mixtures of oil with carbon dioxide and water is essential for reservoir engineering, especially in the processes of enhanced oil recovery and geological storage of carbon dioxide. However, for a comprehensive understanding, the study of simpler systems needs to be completed. In this work the system (n-decane + carbon dioxide + water) was studied as a model (oil + carbon dioxide + water) mixture.

Application of a renormalization-group treatment to the statistical associating fluid theory for potentials of variable range (SAFT-VR).

An accurate prediction of phase behavior at conditions far and close to criticality cannot be accomplished by mean-field based theories that do not incorporate long-range density fluctuations. A treatment based on renormalization-group (RG) theory as developed by White and co-workers has proven to be very successful in improving the predictions of the critical region with different equations of state. The basis of the method is an iterative procedure to account for contributions to the free energy of density fluctuations of increasing wavelengths.

Design of a laboratory for experiments with a pulsed neutron source.

We present the results of a neutron shielding design and optimisation study performed to reduce the exposure to radiological doses arising from a 14 MeV pulsed neutron generator (PNG) having a maximum emission strength of 2.0 x 10(8) neutrons s(-1). The source was intended to be used in a new irradiation facility for the realisation of an experiment on acoustical cavitation in liquids.

Influence of catch-up growth on glucose tolerance and beta-cell function in 7-year-old children: results from the birth to twenty study.

Objective: The aim of this study was to investigate the effect of catch-up growth occurring at different stages of childhood on glucose levels and beta-cell function at 7 years of age.

Methods: Oral glucose tolerance tests were performed on 152 7-year-old children. Anthropometric data were available from birth to 7 years of age.

A kinetic theory description of the viscosity of dense fluids consisting of chain molecules.

An expression for the viscosity of a dense fluid is presented that includes the effect of molecular shape. The molecules of the fluid are approximated by chains of equal-sized, tangentially jointed, rigid spheres. It is assumed that the collision dynamics in such a fluid can be approximated by instantaneous collisions between two rigid spheres belonging to different chains.