How Important are Financial Frictions in the U.S. and Euro Area?

This paper aims to evaluate the importance of frictions in credit markets for business cycles in the U.S. and the Euro area. For this purpose, I modify the DSGE financial accelerator model developed by Bernanke, Gertler and Gilchrist (1999) and estimate it using Bayesian methods. The model is augmented with frictions such as price indexation to past inflation, sticky wages, consumption habits and variable capital utilization. My results indicate that financial frictions are relevant in both areas. Using the Bayes factor as criterion, the data favors the model with financial frictions both in the U.S. and the Euro area in five different specifications of the model. Moreover, the size of the financial frictions is larger in the Euro area.DSGE models; Bayesian estimation; financial accelerator

Wind-Tunnel Investigation of the Effect of Tab Balance on Tab and Control-Surface Characteristics

An investigation was conducted to furnish data on the effect of tab balance on tab and control-surface characteristics. The airfoil tested had a modified NACA 65(1)-012 contour with a plain flap having a chord equal to 25 percent of the wing chord and with a tab having a chord equal to 25 percent of the flap chord and having several nose shapes and overhang lengths. The results of the investigation indicated that, in general, tab balance affected tab hinge-moment characteristics in much the same manner that flap balance affects flap hinge-moment characteristics. A moderate amount of tab balance did not seem to have any adverse effect on flap hinge-moment characteristics

Mechanical caracterisation of polyester resin and corn natural fibers composite

The use of natural fibers as reinforcement in polymer matrix composites is gaining popularity in the development of renewable products. Although glass and other synthetic fiber-reinforced plastics possess high specific strength, their fields of application are very limited because of their inherent higher cost of production. The work deals with the characteristics of fiber composites that can offer several advantages, like low cost, weight savings and relatively good mechanical properties. It focuses on the effects of corn fibers as reinforcement agents in composites. Mechanical testing was performed to qualify the reinforcement properties of the corn fibers and consequently to compare with fiberglass composites

Inclusion of unsteady aerodynamics in longitudinal parameter estimation from flight data

A simple vortex system, used to model unsteady aerodynamic effects into the rigid body longitudinal equations of motion of an aircraft, is described. The equations are used in the development of a parameter extraction algorithm. Use of the two parameter-estimation modes, one including and the other omitting unsteady aerodynamic modeling, is discussed as a means of estimating some acceleration derivatives. Computer generated data and flight data, used to demonstrate the use of the parameter-extraction algorithm are studied

Theoretical span load distributions and rolling moments for sideslipping wings of arbitrary plan form in incompressible flow

A method of computing span loads and the resulting rolling moments for sideslipping wings of arbitrary plan form in incompressible flow is derived. The method requires that the span load at zero sideslip be known for the wing under consideration. Because this information is available for a variety of wings, this requirement should not seriously restrict the application of the present method. The basic method derived herein requires a mechanical differentiation and integration to obtain the rolling moment for the general wing in sideslip. For wings having straight leading and trailing edges over each semispan, the rolling moment due to sideslip is given by a simple equation in terms of plan-form parameters and the lateral center of pressure of the lift due to angle of attack. Calculated span loads and rolling-moment parameters are compared with experimental values. The comparison indicates good agreement between calculations and available experimental data

Static Stability Characteristics of Three Thick Wing Models with Parabolic Plan Forms at a Mach Number of 3.11

An experimental investigation has been made to determine the static stability characteristics of three thick wing models with parabolic plan forms at a Mach number of 3.11 for angles of attack from about -6 to 16 deg. The primary variable was aspect ratio, with the plan-form area and the ratio of base height to span kept the same for all three models. All models had stable, linear pitching-moment curves about the quarter chord of the wing mean aerodynamic chord. The model with the lowest aspect ratio attained a maximum untrimmed lift-drag ratio of about 5.0 at an angle of attack of about 8 deg. Increasing the aspect ratio (which was accompanied by an increase in base area because the ratio of the base height to span was kept constant) caused a decrease in maximum lift-drag ratio. All models were directionally stable for the range of angle of attack of the tests. Addition of a vertical tail to the models caused an increase in the directional stability over the angle-of-attack range. In general, the lateral aerodynamic characteristics of the models were not linear functions of angle of attack over any appreciable angle-of-attack range