Formation of natural gas hydrate is a serious problem in the gas and oil industry because it can plug pipelines and destroy the equipment. This study aimes to evaluate the concentration effect of glycol ethers on their synergism with a commercial kinetic hydrate inhibitor (Luvicap 55W) in sweet natural gas-water systems at a constant temperature of 4 oC and pressure of 95 bar. Hydrate formation...

It has been the purpose of the present paper to investigate and explore the conditions under which the linear relation between Delta/C(D) (0) and Delta in the Hanna-Ashbaugh-Foster-Fyfe equation for the evaluation of equilibrium constants holds, (C(D) (0) is initial concentration of a donor and Delta is the observed chemical shift relative to the chemical shift of the acceptor) to obtain the eq...

We investigate cosmic string models for structure formation which include a non-zero cosmological constant. We nd that the background evolution of density perturbations and modi cations to the scaling behaviour of the strings both act to increase the amount of power present on 100h Mpc scales. We estimate the size of this e ect using an analytic model for the evolution of the string network and...

Abstract Study question Does constant supplementation of antioxidants to the culture media increase blastocyst formation from oocyte donors? Summary answer The increases donors What is known already use a combination various in embryo has recently been investigated explore potential benefit for development and clinical outcomes. However, concentration added only determined by its effect. In thi...

The interaction between benzo-15-crown-5 (B15C5), dibenzo-18-crown-6 (DB18C6), dibenzyl-daza-18crown-6 (DBzDA18C6), N-phenyl-aza-15-crown-5 (NPhA15C5) and dibenzopyridine-18-crown-6 (DBPy18C6) with π-acceptor 2,3-dichloro-5,6-dicyanobenzoquinone (DDQ) in chloroform solution was studied spectrophotometrically. The interaction of B15C5-DDQ and DB18C6-DDQ caused the formation...

the acid-base equilibrium of lorazepam was studied by means of potentiometry andmultiwavelengths spectrophotometry. the stoichiometric equilibrium constants were determinedat 25 °c and constant ionic strength 0.1 mol l-1 (nacl). the acidity constants pk1=1.58±0.05and pk2=11.67±0.07 were found by potentiometry, and pk1=1.54±0.02 and pk2=11.61±0.03 bymulti-wavelengths spectrophotometry. potentiom...