This paper was selected for presentation by an SPE Program Committee following review of information contained in an abstract submitted by the author(s). Contents of the paper, as presented, have not been reviewed by the Society of Petroleum Engineers and are subject to correction by the author(s). The material, as presented, does not necessarily reflect any position of the Society of Petroleum...

We examine the development of a transient spiral arm in a disk galaxy made up of both gas and stars. To this end we have performed numerical simulations in a shearing sheet (basically a rectangular patch of a disc) that contains gas in the form of clouds behaving like Brahic’s (1977) sticky particles, and stars that appear as a background continuum providing the perturbation forces. These are c...

In this paper we compare the accuracy of a range of advanced density models for gas identification from sensor array signals. Density estimation is applied in the construction of classifiers through the use of Bayes rule. Experiments on real sensors data proved the effectiveness of the approach with an excellent classification performance. We compare the classification accuracy of four density ...

A suitable model for predicting the product quality of vacuum gas oil (VGO) catalytic hydrocracking is developed. Data were obtained using an experimental catalytic hydrocracking reactor loaded with the Ni-Mo/Al2O3-SiO2 catalyst. A set of experimental runs was conducted under various operating temperatures from 380 to 450 ℃. Three distribution models were used t...

in this paper, using a one-dimensional simulation model, the reforming process of sour gas, i.e. ch4, co2, and h2s, to the various charged particles and syngas in a dielectric barrier discharge (dbd) reactor is studied. an electric field is applied across the reactor radius, and thus a non-thermal plasma discharge is formed within the reactor. based on the space-time coupled finite element meth...

Fractional flow analysis confirms the advantages of surfactant alternative gas injection (SAG) in enhanced oil recovery, but an adsorption phenomenon that has been affected by several factors, weakens the effectiveness of SAG injection. In this study, the effects of sacrificial agent, gas phase, and surfactant concentration on adsorption density on silica mineral were investigated by static and...

Prolonged anoxia has deleterious effects on islets. Gas-permeable cell culture devices can be used to minimize anoxia during islet culture and especially during shipment when elimination of gas-liquid interfaces is required to prevent the formation of damaging gas bubbles. Gas-permeable bags may have several drawbacks, such as propensity for puncture and contamination, difficult islet retrieval...

The formation of the first stars out of metal-free gas appears to result in stars at least an order of magnitude more massive than in the present-day case. We here consider what controls the transition from a primordial to a modern initial mass function. It has been proposed that this occurs when effective metal line cooling occurs at a metallicity threshold of Z/Z⊙ > 10 . We study the influenc...