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The scope of this work is the experimental and modeling study of adsorptive deep desulfurization of model fuels utilizing activated carbons. Emphasis is given on how oxidative chemical treatment affects the textural and surface chemistry properties and hence the desulfurization kinetics and performance, while the effect of the copresence of aromatics is also investigated. The derivation of the kinetic model and the understanding of adsorption mechanism(s) are also among the main focuses of the work. Two model solutions, one to mimic gasoline/petrol (DBT in hexane) and another for diesel (4,6-DMDBT in hexadecane), with low initial sulfur concentration (20 ppmwS), as well as a model fuel consisting of 4,6-DMDBT, benzene, and naphthalene in hexadecane mimicking the real diesel fuel, were prepared. Adsorption equilibrium and kinetic experiments were conducted, while the results were fitted by simple empirical models and phenomenological models. Chemical treatment through oxidation enhanced the performance of the carbon, reaching a final concentration of less than 2 ppmwS in the case of DBT in hexane and 7.2 ppmwS for 4,6-DMDBT in hexadecane, thus achieving deep desulfurization. In contrast, the copresence of aromatic compounds in high concentrations decreased the efficiency of the carbons, revealing their competitive character in adsorptive desulfurization. Surface diffusion is considered the main mechanism governing the adsorption kinetics. A strong inhibition in diffusion is observed due to the competitive adsorption/interactions, as well as of the already adsorbed compounds. Interestingly, as regards the DBT/hexane system, the hindrance is so strong that the model has to be replaced by a system of two steps in series having kinetics of quite disparate time scales.

Oral poster abstractsMethods: This prospective observational study enrolled 110 consecutive multiparous women with singleton gestations scheduled for labor induction at term. Transvaginal ultrasound for measurement of cervical length was performed and the Bishop score was assessed by digital examination. Receiver operating characteristic (ROC) curves and logistic regression were used for statistical analysis. Results: Labor induction failed in 15 women (14%). In terms of previous obstetric history, women with only previous mid-trimester loss or preterm delivery had a significantly higher risk of failed labor induction than those with at least one previous term delivery. Logistic regression demonstrated that both previous obstetric history and the Bishop score were found to be significant and independent contributing factors for failed labor induction. Further examination of the different components of the Bishop score showed that only previous obstetric history provided a significant contribution to the prediction of failed labor induction. To predict the failure of labor induction, the best cut-off value of Bishop score was 3, with a sensitivity of 73% and a specificity of 44%. Conclusions:The previous obstetric history and the Bishop score independently predicted the failure of labor induction in multiparous women. However, sonographic measurement of cervical length appeared to have poor predictive value for the risk of failed induction. Objectives: The purpose of this study was to evaluate the predictive value of body mass index (BMI), Bishop score, and the sonographic measurement of cervical length for predicting successful labor induction (defined as an ability to achieve the active phase of labor within 1 day after induction) in twin gestations. Methods: This prospective observational study enrolled 50 consecutive women with twin pregnancy at more than 34.0 weeks of gestation scheduled for induction of labor. Transvaginal ultrasound for measurement of cervical length was performed and the Bishop score was assessed by digital examination. Univariate and multivariate analyses were used for statistical analysis. Results: Labor induction was successful in 52% (26/50). Women who had successfully induced labor revealed significantly lower BMI and a lower rate of Cesarean delivery than those who failed to induce labor. However, no significant differences were found regarding median gestational age at the time of labor induction, median cervical length, median Bishop score, distribution of parous and nonparous women, the prevalence of prostaglandin use, and the median birth weight between these two patient groups. To predict the success of labor induction, the best cut-off value of BMI was 29, with a sensitivity of 77% and a specificity of 62%, respectively. Multiple logistic regression demonstrated that only BMI provided a significant contribution to predicting successful labor induction. Conclusions: The BMI independently predicted the success of labor induction in twin gestation. However, sonographic measuremen...