The dynamics and nonlinear wave forcing of a flexible floating structure are investigated experimentally and numerically. The floater was designed to match sub-harmonic rigid-body natural frequencies of typical floating wind turbine substructures, with the addition of a flexible bending mode. Experiments were carried out for three sea states with phase-shifted input signals to allow harmonic separation of the measured response. We find for the weakest sea states that sub-harmonic rigid-body motion is driven by even-harmonic difference frequency forcing, and by linear forcing for the strongest sea state. The flexible mode was tested in a soft, linearly forced layout, and a stiff layout, forced by second-, third- and fourth-harmonic frequency content, for increasing severity of the sea state. Further insight is gained by analysis of the amplitude scaling of the resonant response. A new simplified approach is proposed and compared with the recent method of Orszaghova et al. (J. Fluid Mech., vol. 929, 2021, A32). We find that resonant surge and pitch motions are dominated by even-harmonic potential-flow forcing and that odd-harmonic response is mainly potential-flow driven in surge and mainly drag driven in pitch. The measured responses are reproduced numerically with second-order forcing and quadratic drag loads, using a recent and computationally efficient calculation method, extended here for the heave, pitch and flexible motions. We are able to reproduce the response statistics and power spectra for the measurements, including the subharmonic pitch and heave modes and the flexible mode. Deeper analysis reveals that inaccuracies in the even-harmonic forcing content can be compensated by the odd-harmonic loads.

The surface of the Greenland Ice Sheet is darkening, which accelerates its surface melt. The role of glacier ice algae in reducing surface albedo is widely recognised but not well quantified and the feedbacks between the algae and the weathering crust remain poorly understood. In this letter, we summarise recent advances in the study of the biological darkening of the Greenland Ice Sheet and highlight three key research priorities that are required to better understand and forecast algal-driven melt: (i) identifying the controls on glacier ice algal growth and mortality, (ii) quantifying the spatio-temporal variability in glacier ice algal biomass and processes involved in cell redistribution and (iii) determining the albedo feedbacks between algal biomass and weathering crust characteristics. Addressing these key research priorities will allow us to better understand the supraglacial ice-algal system and to develop an integrated model incorporating the algal and physical controls on ice surface albedo.

The transient pressure field around a moderately thick airfoil is studied as it undergoes ramp-type pitching motions at high Reynolds numbers and low Mach numbers. A unique set of laboratory experiments were performed in a high-pressure wind tunnel to investigate dynamic stall at chord Reynolds numbers in the range of $0.5\times 10^6\leq Re _c\leq 5.5\times 10^6$ in the absence of compressibility effects. In addition to variations of mean angle and amplitude, pitching manoeuvres at reduced frequencies in the range of $0.01\leq k\leq 0.40$ were studied by means of surface-pressure measurements. Independently of the parameter variations, all test cases exhibit a nearly identical stall behaviour characterized by a gradual trailing-edge stall, in which the dynamic stall vortex forms approximately at mid-chord. The location of the pitching window with respect to the Reynolds-number-dependent static stall angle is found to define the temporal development of the stall process. The time until stall onset is characterized by a power law, where a small excess of the static stall angle results in a drastically prolonged stall delay. The reduced frequency exhibits a decrease in impact on the stall development in the case of angle-limited pitching manoeuvres. Beyond a critical reduced frequency, both load magnitudes and vortex evolution become reduced frequency independent and instead depend on the geometry of the motion and the convective time scale, respectively. Overall, the characteristics of vortex evolution induced by dynamic stall show remarkable similarities to the framework of optimal vortex formation reported in Gharib et al. (J. Fluid Mech., vol. 360, 1998, pp. 121–140). The data from this study are publicly available at https://doi.org/10.34770/b3vq-sw14.

The impact of nutrition information on public health is partly determined by the population's level of nutrition literacy (NL), which involves functional NL (such as knowledge of dietary guidelines) and critical NL (such as the ability to distinguish between evidence-based nutrition information and alternative facts). The aim of this cross-sectional study was to describe aspects of functional and critical NL and predictors of NL scores among university students and employees. We recruited at different university campuses, 414 students and 112 employees, of which 80 % were females and 69 % were in the ages of 18–30 years. In total, 82 % reported knowledge about where to find information on nutrition issues, and 70 % were familiar with Norwegian dietary guidelines. Being female, having higher age, being highly physically active and studying or working within health sciences were significant predictors of higher levels of functional nutrition knowledge. Significantly more women than men found it difficult to judge if media information on nutritional issues could be trusted (69 v. 54 %) and found it hard to distinguish between scientific and non-scientific information about diet (60 v. 42 %). Our findings indicate that for a sample of university students and employees, affiliation with health sciences, being female, having a higher age and being physically active were associated with higher functional NL. Women did, however, seem to have lower levels of some aspects of critical NL, e.g. how to critically judge nutrition information. A more thorough assessment of NL in university students and employees should therefore be conducted.

Prototyping is essential for fuzzy front-end product development. The prototyping process answers questions about critical assumptions and supports design decisions, but it is often unstructured and context-dependent. Previously, we showed how to guide novice designers in early development stages with prototyping milestones. Here, we studied the prototyping success perceived by novice design teams. This was done in two steps: (1) teams were asked to assign each prototype to a milestone, a specific purpose, a fidelity level, and a human-centered design lens, and then evaluate the success using a predefined set of criteria. (2) Teams were interviewed about the success of the prototyping process, this time using self-chosen criteria. Results related to (1) show that teams perceived prototyping activities with respect to desirability and problem validation significantly less successful than prototyping activities towards feasibility and solution validation. Results related to (2) show that teams mostly chose success criteria related to how well prototypes supported communication, decision making, learning, and tangibility. This insight may be used to give priorities to further improvement of methods and guidance in these areas.

In this paper, we conceptualize, analyze, and assemble a prototype adaptive surface system capable of morphing its geometric configuration using an array of linear actuators to impose omnidirectional movement of objects that lie on the surface. The principal focus and contribution of this paper is the derivation of feedback control protocols–for regulating the actuators’ length in order to accomplish the object conveyance task–that scale with the number of actuators and the nonlinear kinematic constraints of the morphing surface. Simulations and experimental results demonstrate the advantages of distributed manipulation over static-shaped feeders.

Prototyping is an essential activity in product development, but novice designers lack awareness and purpose when they prototype. To foster prototyping mindsets in novice designers, we introduce a prototyping support tool that structures prototyping activities. This paper outlines the Prototyping Planner's development, evolution, and evaluation by 125 novice designers. The majority of novice designers’ experienced that the Prototyping Planner helped them create purposeful prototypes and evaluate results from prototyping.

The design of government portfolios – that is, the distribution of competencies among government ministries and office holders – has been largely ignored in the study of executive and coalition politics. This article argues that portfolio design is a substantively and theoretically relevant phenomenon that has major implications for the study of institutional design and coalition politics. The authors use comparative data on portfolio design reforms in nine Western European countries since the 1970s to demonstrate how the design of government portfolios changes over time. Specifically, they show that portfolios are changed frequently (on average about once a year) and that such shifts are more likely after changes in the prime ministership or the party composition of the government. These findings suggest a political logic behind these reforms based on the preferences and power of political parties and politicians. They have major implications for the study of institutional design and coalition politics.

Ice algae are a key component in polar marine food webs and have an active role in large-scale biogeochemical cycles. They remain extremely under-sampled due to the coarse nature of traditional point sampling methods compounded by the general logistical limitations of surveying in polar regions. This study provides a first assessment of hyperspectral imaging as an under-ice remote-sensing method to capture sea-ice algae biomass spatial variability at the ice/water interface. Ice-algal cultures were inoculated in a unique inverted sea-ice simulation tank at increasing concentrations over designated cylinder enclosures and sparsely across the ice/water interface. Hyperspectral images of the sea ice were acquired with a pushbroom sensor attaining 0.9 mm square pixel spatial resolution for three different spectral resolutions (1.7, 3.4, 6.7 nm). Image analysis revealed biomass distribution matching the inoculated chlorophyll a concentrations within each cylinder. While spectral resolutions >6 nm hindered biomass differentiation, 1.7 and 3.4 nm were able to resolve spatial variation in ice algal biomass implying a coherent sensor selection. The inverted ice tank provided a suitable sea-ice analogue platform for testing key parameters of the methodology. The results highlight the potential of hyperspectral imaging to capture sea-ice algal biomass variability at unprecedented scales in a non-invasive way.

Based on findings from the literature on campaign effects on the one hand, and the literature on European Parliament elections on the other, we propose a model of European Parliamentary elections in which the campaign shift the calculus of electoral support, making differences in national political allegiances less important and attitudes about the European project more important by informing voters of and getting them interested in European politics. In effect, we argue that the political campaign leading up to the election makes European Parliament elections less second order. While previous studies have demonstrated that EU issues can matter for voting behavior in European Parliament elections, existing research has drawn on post-election surveys that do not enable us to capture campaign effects. Our contribution is to assess the impact of a campaign by utilizing a rolling cross-sectional survey that enables us to track how voters were affected by the campaign. Our findings show that campaigns do have an effect on European Parliament election outcomes, in that they provide information that enables voters to make decisions based on their attitude on European issues, making voter decision-making more dominated by EU issue voting.

Tectatodinium rugulatum (Hansen, 1977) McMinn, 1988, from the lower Danian of Denmark, is considered conspecific with, and a junior synonym of, the extant thermophilic species Tectatodinium pellitum Wall, 1967. However, the Danian material, based on holotype and topotype specimens, appears to show a degree of morphologic variability not seen in younger material. The accepted stratigraphic range base of Tectatodinium pellitum is now extended to the lower Danian, where this species appears to be a useful biostratigraphic marker in the Danish North Sea basin.

In modern democracies, the representation of voter interests and preferences is primarily the job of political parties and their elected officials. These patterns can, however, change when the issues that are at stake concern the interests of social groups represented by all relevant parties of a political system. In this article we focus on the behavior of female MPs in the parliament of Weimar Germany and, thus, on a parliament where legislative party discipline was very high. On the basis of a dataset containing information on the legislative voting behavior of MPs, we show that gender, even when controlling for a battery of further theoretically derived explanatory factors, had a decisive impact on the MPs' voting behavior on a law proposal to curb the spread of sexually transmitted diseases.