Forward pi^0 Production and Associated Transverse Energy Flow in Deep-Inelastic Scattering at HERA

Deep-inelastic positron-proton interactions at low values of Bjorken-x down to x \approx 4.10^-5 which give rise to high transverse momentum pi^0 mesons are studied with the H1 experiment at HERA. The inclusive cross section for pi^0 mesons produced at small angles with respect to the proton remnant (the forward region) is presented as a function of the transverse momentum and energy of the pi^0 and of the four-momentum transfer Q^2 and Bjorken-x. Measurements are also presented of the transverse energy flow in events containing a forward pi^0 meson. Hadronic final state calculations based on QCD models implementing different parton evolution schemes are confronted with the data.Comment: 27 pages, 8 figures and 3 table

Inelastic photoproduction of J/Psi mesons at HERA

An analysis of inelastic photoproduction of J/Psi mesons is presented using data collected at the ep collider HERA corresponding to an integrated luminosity of above 80pb-1. Differential and double differential cross sections are measured in a wide kinematic region: 6

Direct adjustment of wax thermodynamic model parameter to micro Differential Scanning Calorimetry thermograms

ACLInternational audienceAmong the flow assurance subjects, wax deposition plays a major role. As exploration an oil production moves towards deeper water frontiers, longer tiebacks increase the risk of wax deposition, which is assessed through modeling. In modeling schemes, the phase behavior of solid wax is essential and it is available through either a measured solubility curve or through thermodynamic models. These thermodynamic models normally need tuning and, due to the experimental difficulties of measuring solubility curves for real fluids, are tuned to the wax appearance temperature (WAT). To reduce the uncertainties of adjusting a model to just one point, a procedure to directly simulate DSC curves from a liquid-solid thermodynamic model is proposed. This new strategy allows a full thermogram adjustment without going through the empirical integration of the experimental DSC. Experimental DSC thermograms and simulated curves are presented for five standard single wax mixtures. Then, the solubility curves obtained from the model are compared to the experimental literature data and the difference between simulated wax disappearance temperature (WDT), experimental WDT and experimental wax appearance temperature (WAT) are discussed. © 2017 Elsevier B.V

Paraffin solubility and calorimetric data calculation using Peng-Robinson EoS and modified UNIQUAC models

ACLInternational audienceWax deposition receives increasing attention as oil industries moves towards hostile environments. Production in deep water scenarios and even the Artic pushes the boundaries of flow assurance, especially those related to wax precipitation and deposition. Thus, modeling wax phase behavior becomes central to minimize production costs. Although different thermodynamic models are available in the literature, only the solubility curve, either entirely or only its first point, the wax appearance temperature, are used to differentiate them. It is alternatively proposed to compare these models against DSC thermograms. The results show that a liquid model based on Peng-Robinson EoS using van der Waals mixing and combining rules together with a solid model based on the modified UNIQUAC scheme can reproduce the experimental thermograms for the studied systems. As EoS's are widely used by oil companies to describe live oil fluid behavior, the proposed scheme can be readily applied to real fluids, reducing uncertainties associated to model tuning. Moreover, we show that the multiple solid solutions model, using modified UNIQUAC, presents a better description of solubility and calorimetric data when compared with the multisolid and ideal solid solution models. © 2017 Elsevier B.V

Paraffin solubility curves of diesel fuels from thermodynamic model adjusted through experimental DSC thermograms

ACLInternational audienc

High pressure phase equilibria of carbon dioxide + n-alkanes mixtures: Experimental data and modeling

ACLInternational audienc

Variability and Evolution of Shallow Continental Shelf Systems off Rio de Janeiro State, Santos Basin - Brazil

International audienc

Paraffin solubility and calorimetric data calculation using Peng-Robinson EoS and modified UNIQUAC models

ACLInternational audienceWax deposition receives increasing attention as oil industries moves towards hostile environments. Production in deep water scenarios and even the Artic pushes the boundaries of flow assurance, especially those related to wax precipitation and deposition. Thus, modeling wax phase behavior becomes central to minimize production costs. Although different thermodynamic models are available in the literature, only the solubility curve, either entirely or only its first point, the wax appearance temperature, are used to differentiate them. It is alternatively proposed to compare these models against DSC thermograms. The results show that a liquid model based on Peng-Robinson EoS using van der Waals mixing and combining rules together with a solid model based on the modified UNIQUAC scheme can reproduce the experimental thermograms for the studied systems. As EoS's are widely used by oil companies to describe live oil fluid behavior, the proposed scheme can be readily applied to real fluids, reducing uncertainties associated to model tuning. Moreover, we show that the multiple solid solutions model, using modified UNIQUAC, presents a better description of solubility and calorimetric data when compared with the multisolid and ideal solid solution models. © 2017 Elsevier B.V