Simulations of fiber flocculation: effects of fiber properties and interfiber friction

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Kinetics of Propane Cracking Related to Its Use as a Heat-Transfer Fluid

The kinetics of propane cracking at high pressure were measured to evaluate its suitability as a heat-transfer fluid, in either a closed loop or directly injected into the formation, to retort oil shale <i>in situ</i>. Rate constants were measured in batch reactors at isothermal temperatures from 450 to 540 °C and at constant heating rates of 1.5 and 3.6 °C/min. Rate constants were also measured in a flow loop for isothermal temperatures ranging from 440 to 473 °C. The lowest temperatures in the batch autoclave experiments showed evidence of autocatalytic kinetic behavior, but the higher temperature batch experiments and the flow loop were more nearly first-order. The overall rate constants were consistent with an extrapolation of results from higher temperature measurements. Product selectivity changed as a function of conversion, with low conversion products rich in C₄₊ products and high conversion products predominantly methane. A combination of the propane kinetics with simple heat balance calculations shows that more than enough propane is supplied by the retorting operation to balance the consumption by cracking, making the use of propane for the heat-transfer fluid self-sustaining

Rheology of sheared flexible fiber suspensions via fiber-level simulations

This material is presented to ensure timely dissemination of scholarly and technical work. Copyright and all rights therein are retained by authors or by other copyright holders. All persons copying this information are expected to adhere to the terms and constraints invoked by each author's copyright. In most cases, these works may not be reposted without the explicit permission of the copyright holder

Absence of XMRV Retrovirus and Other Murine Leukemia Virus-Related Viruses in Patients with Chronic Fatigue Syndrome ▿ ¶

Chronic fatigue syndrome (CFS) is a multisystem disorder characterized by prolonged and severe fatigue that is not relieved by rest. Attempts to treat CFS have been largely ineffective primarily because the etiology of the disorder is unknown. Recently, CFS has been associated with xenotropic murine leukemia virus-related virus (XMRV) as well as other murine leukemia virus (MLV)-related viruses, though not all studies have found these associations. We collected blood samples from 100 CFS patients and 200 self-reported healthy volunteers from the same geographical area. We analyzed these in a blind manner using molecular, serological, and viral replication assays. We also analyzed samples from patients in the original study that reported XMRV in CFS patients. We did not find XMRV or related MLVs either as viral sequences or infectious viruses, nor did we find antibodies to these viruses in any of the patient samples, including those from the original study. We show that at least some of the discrepancy with previous studies is due to the presence of trace amounts of mouse DNA in the Taq polymerase enzymes used in these previous studies. Our findings do not support an association between CFS and MLV-related viruses, including XMRV, and the off-label use of antiretrovirals for the treatment of CFS does not seem justified at present