34 research outputs found
Direct calculation of sensitivity to the coefficients of the basic submatrix in parametric linear programming
Direct calculation of sensitivity to the coefficients of the basic submatrix in parametric linear programming
Direct calculation of sensitivity to the coefficients of the basic submatrix in parametric linear programming
Hemodynamic and clinical response to three-day infusion of sulmazol (AR-L 115 BS) in severe congestive heart failure
Sulmazol (AR-L 115 BS) is a new positively inotropic drug with arterial and venous vasodilating properties. We studied the effects of sulmazol (three-day infusion) on clinical tolerance, hemodynamics, and blood gas levels in ten patients with severe chronic heart failure. The hemodynamic monitoring included a Swan-Ganz catheter in the pulmonary artery and a radial catheter. Blood gas levels were determined on samples of arterial and mixed venous blood. After 24 hours of infusion, there was a significant increase in cardiac index (2 to 2.5 L/min/sq m; p<0.005) and a signification decrease in pulmonary-wedge pressure (28 to 19 mm Hg; p<0.001) and in right atrial pressure (7 to 4 mm Hg; p<0.001) without significant changes in heart rate and systolic blood pressure. These benefical effects lasted during the three days of infusion. Oxygen delivery was significantly increased (350 to 443 ml/min/sq m; p<0.005) without significant change in arterial oxygen tension. The side effects included nausea, vomiting, anorexia, and mild thrombocytopenia. We conclude that sulmazol is a potent drug which may improve severely deteriorated left and right ventricular function in patients with chronic refractory heart failure without affecting the heart rate and the systolic blood pressure.SCOPUS: ar.jinfo:eu-repo/semantics/publishe
Three-dimensional pseudo-unsteady viscous-inviscid interaction for wings in transonic flow
editorial reviewedAircraft aerodynamic and aeroelastic optimization is applied increasingly often at the
preliminary design stage. Performing such optimizations involves many design variables
and higher-fidelity solutions of the Reynolds-Averaged Navier-Stokes equations have significant
computational cost that is incompatible with repeated application. The tools
used to assess the aerodynamic quality of a design within an optimization framework
must be computationally efficient. The present work introduces a viscous-inviscid interaction
methodology in three dimensions whereby inviscid solutions of the full-potential
equation are coupled with a viscous solver based on the integral boundary layer equations.
A novel pseudo-unsteady approach is used to ensure numerical stability when
considering mildly separated flows and shock waves in the transonic regime. The solvers
are coupled through a strip-based methodology in which chordwise boundary layer sections
are defined independently of the inviscid unstructured mesh on the surface of the
wing. The present methodology is demonstrated for transonic flow over the ONERA
M6 and LANN wings. Results show good agreement with reference data on the inboard
sections while some discrepancies between the present methodology and higher
fidelity data exist in the outboard region of the wings. The methodology is shown to
be computationally efficient and suitable for use in an optimization framework