ExxonMobil

About: ExxonMobil is a company organization based out in Irving, Texas, United States. It is known for research contribution in the topics: Catalysis & Polymer. The organization has 16969 authors who have published 23758 publications receiving 535713 citations. The organization is also known as: Exxon Mobil Corporation & Exxon Mobil Corp..

Production of aromatics from methane

Abstract: In a process for converting methane to aromatic hydrocarbons, a feed containing methane is supplied to one or more reaction zone(s) containing catalytic material operating under reaction conditions effective to convert at least a portion of the methane to aromatic hydrocarbons; the reaction zone(s) being operated with an inverse temperature profile.

Phase Coexistence of a Stockmayer Fluid in an Applied Field

Abstract: We examine two apects of Stockmayer fluids, which consist of point dipoles that additionally interact via an attractive Lennard-Jones potential. We perform Monte Carlo simulations to examine the effect of an applied field on the liquid-gas phase coexistence and show that a magnetic fluid phase does exist in the absence of an applied field. As part of the search for the magnetic fluid phase, we perform Gibbs ensemble simulations to determine phase coexistence curves at large dipole moments, \ensuremath{\mu}. The critical temperature is found to depend linearly on ${\mathrm{\ensuremath{\mu}}}^{2}$ for intermediate values of \ensuremath{\mu} beyond the initial nonlinear behavior near \ensuremath{\mu}=0 and less than the \ensuremath{\mu} where no liquid-gas phase coexistence has been found. For phase coexistence in an applied field, the critical temperatures as a function of the applied field for two different \ensuremath{\mu} are mapped onto a single curve. The critical densities change very little as a function of applied field. We also verify that in an applied field the liquid droplets within the two-phase coexistence region become elongated in the direction of the field.

Risk assessment in the 21st century: Roadmap and matrix

Abstract: The RISK21 integrated evaluation strategy is a problem formulation-based exposure-driven risk assessment roadmap that takes advantage of existing information to graphically represent the intersection of exposure and toxicity data on a highly visual matrix. This paper describes in detail the process for using the roadmap and matrix. The purpose of this methodology is to optimize the use of prior information and testing resources (animals, time, facilities, and personnel) to efficiently and transpar ently reach a risk and/or safety determination. Based on the particular problem, exposure and toxicity data should have sufficient precision to make such a decision. Estimates of exposure and toxicity, bounded by variability and/or uncertainty, are plotted on the X- and Y-axes of the RISK21 matrix, respectively. The resulting intersection is a highly visual representation of estimated risk. Decisions can then be made to increase precision in the exposure or toxicity estimates or declare that the available information is sufficient. RISK21 represents a step forward in the goal to introduce new methodolo gies into 21st century risk assessment. Indeed, because of its transparent and visual process, RISK21 has the potential to widen the scope of risk communication beyond those with technical expertise.