Investigation of the olive mill solid wastes pellets combustion in a counter-current fixed bed reactor

Combustion tests and gaseous emissions of olive mill solid wastes pellets (olive pomace (OP), and olive pits (OPi)) were carried out in an updraft counter-current fixed bed reactor. Along the combustion chamber axis and under a constant primary air flow rate, the bed temperatures and the mass loss rate were measured as functions of time. Moreover, the gas mixture components such as O2, organic carbon (Corg), CO, CO2, H2O, H2, SO2, and NOx (NO + NO2) were analyzed and measured. The reaction front positions were determined as well as the ignition rate and the reaction front velocity. We have found that the exhaust gases are emitted in acceptable concentrations compared to the combustion of standard wood pellets reported in the literature (EN 303-5). It is shown that the bed temperature increased from the ambient value to a maximum value ranging from 750 to 1000 °C as previously reported in the literature. The results demonstrate the promise of using olive mill solid waste pellets as an alternative biofuel for heat and/or electricity production

Neutral Bystander, Intrusive Micromanager, or Useful Catalyst?

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/73380/1/j.1541-0072.1995.tb01746.x.pd

HIV-1 Vpu Protein Mediates the Transport of Potassium in Saccharomyces cerevisiae

Human immunodeficiency virus type 1 (HIV-1) Vpu is an integral membrane protein that belongs to the viroporin family. Viroporins interact with cell membranes, triggering membrane permeabilization and promoting release of viral particles. In vitro electrophysiological methods have revealed changes in membrane ion currents when Vpu is present; however, in vivo the molecular mechanism of Vpu at the plasma membrane is still uncertain. We used the yeast Saccharomyces cerevisiae as a genetic model system to analyze how Vpu ion channel impacts cellular homeostasis. Inducible expression of Vpu impaired cell growth, suggesting that this viral protein is toxic to yeast cultures. This toxicity decreased with extracellular acidic pH. Also, Vpu toxicity diminished as the extracellular K(+) concentration was increased. However, expression of the Vpu protein suppresses the growth defect of K(+) uptake-deficient yeast (Δtrk1,2). The phenotype rescue of these highly hyperpolarized cells was almost total when they were grown in medium supplemented with high concentrations of KCl (100 mM) at pH 7.0 but was significantly reduced when the extracellular K(+) concentration or pH was decreased. These results indicate that Vpu has the ability to modify K(+) transport in both yeast strains. Here, we show also that Vpu confers tolerance to the aminoglycoside antibiotic hygromycin B in Δtrk1,2 yeast. Our results suggest that Vpu interferes with cell growth of wild-type yeast but improves proliferation of the hyperpolarized trk1,2 mutant by inducing plasma membrane depolarization. Furthermore, evaluation of the ion channel activity of the Vpu protein in Δtrk1,2 yeast could aid in the development of a high-throughput screening assay for molecules that target the retroviral protein.This study was supported by Grants PI PI05/00013 and PI08/0912 from Fondo de Investigación Sanitaria. L.H. and N.M. were holders of Predoctoral Fellowships from Instituto de Salud Carlos III.S