Children’s Gender Identity in Lesbian and Heterosexual Two-Parent Families

This study compared gender identity, anticipated future heterosexual romantic involvement, and psychosocial adjustment of children in lesbian and heterosexual families; it was furthermore assessed whether associations between these aspects differed between family types. Data were obtained in the Netherlands from children in 63 lesbian families and 68 heterosexual families. All children were between 8 and 12 years old. Children in lesbian families felt less parental pressure to conform to gender stereotypes, were less likely to experience their own gender as superior and were more likely to be uncertain about future heterosexual romantic involvement. No differences were found on psychosocial adjustment. Gender typicality, gender contentedness and anticipated future heterosexual romantic involvement were significant predictors of psychosocial adjustment in both family types

Auctioning Incentive Contracts: An Experimental Study

In this note, we experimentally examine the relative performance of price-only auctions and multi-attribute auctions. We do so in procurement settings where the buyer can give the winning bidder incentives to exert effort on non-price dimensions after the auction. Both auctions theoretically implement the surplus maximizing mechanism. Our experiment confirms this result. Moreover, we observe that the "pie" is shared the same in both auctions between buyer and suppliers both in theory and in the lab (after accounting for learning effects).Key words: Procurement; Price-only auctions; Multi-attribute auctions; Incentive Contracts; Laboratory Experimen

Task-dependent evaluative processing of moral and emotional content during comprehension: an ERP study

Recently, we showed that when participants passively read about moral transgressions (e.g., adultery) they implicitly engage in the evaluative (good–bad) categorization of incoming information, as indicated by a larger event-related brain potential (ERP) positivity to immoral than moral scenarios (Leuthold, Kunkel, Mackenzie, & Filik, 2015). Behavioral and neuroimaging studies indicated that explicit moral tasks prioritize the semantic-cognitive analysis of incoming information but that implicit tasks, as used in Leuthold et al. (2015), favor their affective processing. Therefore, it is unclear whether an affective categorization process is also involved when participants perform explicit moral judgments. Thus, in two experiments, we used similarly constructed morality and emotion materials for which their moral and emotional content had to be inferred from the context. Target sentences from negative vs. neutral emotional scenarios and from moral vs. immoral scenarios were presented using rapid serial visual presentation. In Experiment 1, participants made moral judgments for moral materials and emotional judgments for emotion materials. Negative compared to neutral emotional scenarios elicited a larger posterior ERP positivity (LPP) about 200 ms after critical word onset, whereas immoral compared to moral scenarios elicited a larger anterior negativity (500-700 ms). In Experiment 2, where the same emotional judgment to both types of materials was required, a larger LPP was triggered for both types of materials. These results accord with the view that morality scenarios trigger a semantic-cognitive analysis when participants explicitly judge the moral content of incoming linguistic information but an affective evaluation when judging their emotional content

Three-dimensional flow and load characteristics of flexible revolving wings at low Reynolds number

Increasing interest in the field of micro air vehicles has stimulated research activities regarding biological flapping-wing flight. An important characteristic of biological flapping-wing flight that is not commonly taken into account in mechanical model simulations is the influence of wing flexibility. This experimental study explores the flow field and fluid-dynamic loads generated by revolving low-aspect-ratio wings with different degree of chordwise flexibility at a Reynolds number of 10,000. The experimental campaign consisted of phase-locked tomographic particle image velocimetry (PIV) measurements complemented with simultaneous force measurements. The three-dimensional velocity fields are captured in three measurement volumes positioned side-by-side along the span of the wing for different phases of the revolving motion, generating a time-resolved volumetric velocity field data set. Subsequently, from the velocity data the pressure fields are reconstructed as well as the loads acting on the wing. In this study the link between the temporal evolution of the vortical structures and the associated pressure forces acting on the wing is investigated in detail.Aerospace EngineeringAerodynamics, Wind Energy & Propulsio

Three-dimensional flow and load characteristics of flexible revolving wings

The flow field and fluid-dynamic loads of revolving low-aspect-ratio chordwise-flexible wings are studied experimentally at a Reynolds number of 10,000. The investigation involves phase-locked tomographic particle image velocimetry (PIV) complemented with force measurements. The pressure fields are reconstructed from the three-dimensional velocity fields in a complete volume around the wing. For decreasing flexural stiffness, the coherence of this vortex system and spanwise transport of vorticity along the axis of the leading edge vortex (LEV) increase, which contribute to the stability and retention of the LEV. As the LEV low-pressure region becomes smaller with increasing flexibility, the total force on the wing is reduced, while it is tilted towards the lift direction due to the wing deformation. As a result, the drag is significantly suppressed, while the lift remains relatively high. Consequently, the lift-to-drag ratio increases with increasing flexibility and correlates well with the geometric angle of attack. While the sectional lift along the full span is comparable for the different wings, the sectional drag is significantly reduced at the outboard wing for increasing flexibility. The centroids of lift and drag are located at approximately 70% of the span for all wings throughout the complete revolving motion. Finally, the process of vortex breakdown is found to be related to the formation of a positive spanwise pressure gradient.Aerodynamic

Determination of pressure and load characteristics of flexible revolving wings by means of tomographic PIV

This study explores the flow field and fluid-dynamic loads generated by revolving low-aspect-ratio wings. The pressure field and load characteristics are successfully reconstructed from the phase-locked tomographic measurements in three independently measured volumes along the span of the wing. The vortical structures encompass a low pressure region and the spatial gradient information of the pressure field provides greater insights in their stability mechanisms. The low pressure region associated with the leading edge vortex and its close position to the wing surface are responsible for the high resultant forces acting on the wing. Simultaneous force measurements show a reasonable agreement with the reconstructed loads. The sectional lift and drag characteristics provide greater insights into the distributed load mechanisms along the span.Aerodynamic

Three-dimensional flow and load characteristics of flexible revolving wings at low Reynolds number

This study explores the flow field and fluid-dynamic loads generated by revolving low-aspect-ratio flat plate wings undergoing a revolving motion starting from rest. Three wings with different degree of chordwise flexural stiffness (i.e., rigid, moderate flexibility and high flexibility) have been tested in order to investigate the influence of the wing flexibility. The wings have an angle of attack of 45 deg in their undeformed condition. The measurements have been performed in a water tank at a Reynolds number of 10,000 based on the chord length and terminal velocity at the 75% span position. The experimental campaign consists of phase-locked tomographic particle image velocimetry measurements complemented with simultaneous force measurements The three-dimensional velocity fields are captured in three measurement volumes positioned side-by-side along the span of the wing for different phases of the revolving motion, generating a time-resolved volumetric velocity field data set. Subsequently, from the velocity data the pressure fields are reconstructed as well as the loads acting on the wing.Aerodynamic

Flow Field Characteristics of Translating and Revolving Flexible Wings

This study explores the effects of rotational mechanisms on the characteristics of the leading edge vortex (LEV) by comparing translating and revolving flexible wings that are started from rest. Tomographic particle image velocimetry (tomographic-PIV) technique was employed to acquire three-dimensional flow fields for the revolving wings, while planar flow fields for the case of translating wings were acquired via 2D2C-PIV measurements. The comparison of flow fields between the two motion kinematics reveals similar behavior of the vortical structures yet the LEV circulation in the translating wings has higher values. The LEV centroid in the revolving cases stays above the leading-edge, while in the translating wings, it always remains at a lower position. The effect of high flexibility results in the retention of LEV closer to the wing surface for both cases.Aerodynamic