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The purpose of this paper is to analyze numerically the blowup in finite time of the solutions to a one-dimensional, bidirectional, nonlinear wave model equation for the propagation of small-amplitude waves in shallow water, as a function of the relaxation time, linear and nonlinear drift, power of the nonlinear advection flux, viscosity coefficient, viscous attenuation, and amplitude, smoothness and width of three types of initial conditions.

An implicit, first-order accurate in time, finite difference method valid for semipositive relaxation times has been used to solve the equation in a truncated domain for three different initial conditions, a first-order time derivative initially equal to zero and several constant wave speeds.

The numerical experiments show a very rapid transient from the initial conditions to the formation of a leading propagating wave, whose duration depends strongly on the shape, amplitude and width of the initial data as well as on the coefficients of the bidirectional equation. The blowup times for the triangular conditions have been found to be larger than those for the Gaussian ones, and the latter are larger than those for rectangular conditions, thus indicating that the blowup time decreases as the smoothness of the initial conditions decreases. The blowup time has also been found to decrease as the relaxation time, degree of nonlinearity, linear drift coefficient and amplitude of the initial conditions are increased, and as the width of the initial condition is decreased, but it increases as the viscosity coefficient is increased. No blowup has been observed for relaxation times smaller than one-hundredth, viscosity coefficients larger than ten-thousandths, quadratic and cubic nonlinearities, and initial Gaussian, triangular and rectangular conditions of unity amplitude.

The blowup of a one-dimensional, bidirectional equation that is a model for the propagation of waves in shallow water, longitudinal displacement in homogeneous viscoelastic bars, nerve conduction, nonlinear acoustics and heat transfer in very small devices and/or at very high transfer rates has been determined numerically as a function of the linear and nonlinear drift coefficients, power of the nonlinear drift, viscosity coefficient, viscous attenuation, and amplitude, smoothness and width of the initial conditions for nonzero relaxation times.

In this paper, we consider the Heisenberg groups which play a crucial role in both geometry and theoretical physics.

In the first part, we retrieve the geometry of left-invariant Randers metrics on the Heisenberg group H_2n+1, of dimension 2n + 1. Considering a left-invariant Randers metric, we give the Levi-Civita connection, curvature tensor, Ricci tensor and scalar curvature and show the Heisenberg groups H_2n+1 have constant negative scalar curvature.

In the second part, we present our main results. We show that the Heisenberg group H_2n+1 cannot admit Randers metric of Berwald and Ricci-quadratic Douglas types. Finally, the flag curvature of Z-Randers metrics in some special directions is obtained which shows that there exist flags of strictly negative and strictly positive curvatures.

In this work, we present complete Reimannian geometry of left invarint-metrics on Heisenberg groups. Also, some geometric properties of left-invarainat Randers metrics will be studied.

This paper aims to contribute to the multinational company (MNC) literature by studying the diffusion of a management idea within an MNC and its interaction with the MNC’s corporate immune system (CIS).

The qualitative single case study draws on evidence of how a management idea augments within an MNC and changes its development practice.

The study identifies four phases of the diffusion process and presents the interaction between the management idea and the CIS in each phase.

The more subsidiaries within an MNC that take the initiative to adopt a management idea, the harder will it become for the headquarters (HQ) to reject it. Thus, to ensure that changes in management practices are based on informed and, ideally, deliberate decisions, managers should critically evaluate management ideas immediately at inception.

The study breaks new ground by explaining how the CIS reacts to the diffusion of management ideas in MNCs.

This paper investigates the integration of leadership training into IT curricula to develop current and future skills needed by the IT job market. The technical and non-technical skills required for IT professionals are presented and a conceptual model for including leadership training in technical courses is outlined. To implement this model, we adopted the Problem-Based Learning approach to teach an IT course. Qualitative and quantitative data were gathered, through a survey, from 52 undergraduate students in the College of Information Technology at Zayed University. Our results show that our adopted approach was successful in teaching IT skills as well as developing leadership skills. Given these findings, we highlight the importance and feasibility of integrating leadership development on a daily basis within technical courses to develop both the technical and non technical skills required by the job market.

This study aims to analyse the non-linear losses of a porous media (stack) composed by parallel plates and inserted in a resonator tube in oscillatory flows by proposing numerical correlations between pressure gradient and velocity.

The numerical correlations origin from computational fluid dynamics simulations, conducted at the microscopic scale, in which three fluid channels representing the porous media are taken into account. More specifically, for a specific frequency and stack porosity, the oscillating pressure input is varied, and the velocity and the pressure-drop are post-processed in the frequency domain (Fast Fourier Transform analysis).

It emerges that the viscous component of pressure drop follows a quadratic trend with respect to velocity inside the stack, while the inertial component is linear also at high-velocity regimes. Furthermore, the non-linear coefficient b of the correlation ax + bx² (related to the Forchheimer coefficient) is discovered to be dependent on frequency. The largest value of the b is found at low frequencies as the fluid particle displacement is comparable to the stack length. Furthermore, the lower the porosity the higher the Forchheimer term because the velocity gradients at the stack geometrical discontinuities are more pronounced.

The main novelty of this work is that, for the first time, non-linear losses of a parallel plate stack are investigated from a macroscopic point of view and summarised into a non-linear correlation, similar to the steady-state and well-known Darcy–Forchheimer law. The main difference is that it considers the frequency dependence of both Darcy and Forchheimer terms. The results can be used to enhance the analysis and design of thermoacoustic devices, which use the kind of stacks studied in the present work.

The purpose of this paper is to describe and discuss how and to what extent creative dialogue processes can have an impact on regional political planning processes in Norway. Politicians at Nordland County invited representatives from six different regions in Nordland to participate in café dialogues.

The empirical material is collected from café-dialogues in Northern Norway in which representatives from civil society, business organizations, local government, and NGOs participated. The data processing is based on triangulation of hermeneutic interpretation, frequencies, and factor analysis.

The findings indicate that most people want a “greener” future; this can be described as sustainable societies based on ecological production, distribution, consumption, and redistribution. People take on a more radical position in their ideas about the future than most politicians. The factor analysis grouped the participants into the following categories; “Ecological economics”, “Small is beautiful”, “Entrepreneurs”, and “Growth and control”. A large number of the participants are categorized either as “Circulation economics” or “Small is beautiful”.

To solve the challenges of modern society politicians can instigate more radical solutions than they are in the habit of doing. The participants in the café dialogues describe fundamental changes in order to attain viable local societies per 2030.

In this paper the authors demonstrate that cultural creatives in the USA give a relevant context for interpreting attitudes to change in small societies in Northern Norway.

Internal gearings are commonly used in transmissions due to their advantages like high-power density. To ensure high efficiency, load-carrying capacity and good noise behavior, a profound knowledge of the local gear mesh is essential. The tooth contact of internal gears relates to a convex and concave surface that form a conformal contact. This is in contrast to external gears, where two convex surfaces form a contraformal contact. This paper aims at a better understanding of conformal contacts under elastohydrodynamic lubrication (EHL) to improve the design of internal gearings.

An existing numerical EHL model is used for studying the characteristic properties of a hard conformal EHL line contact. A hard contraformal EHL line contact is studied as reference. Non-Newtonian fluid behavior and thermal effects are considered. By taking into account the local contact conformity and kinematics, the effects and relevance of the curvature of the lubricant gap and micro-slip are analyzed. In a parameter study, scale effects of the contact radii on film thickness, temperature rise and friction are examined.

The curvature of the lubricant gap and effects of micro-slip are small in hard conformal EHL line contacts. For high micro-slip, it can be neglected. Hence, the modeling of conformal contacts using an equivalent geometry of the contact problem is reasonable. The parameter study shows beneficial tribological aspects of the conformal contact compared to the contraformal contact. Higher film thickness and lower fluid coefficient of friction are observed for conformal contacts, which can be attributed to lower pressures for the case of the same external normal force, or to a higher contact temperature rise for the case of equivalent contact pressure.

Despite its widespread existence, the local geometry and kinematics in hard conformal EHL line contacts like in internal gearings have been rarely studied. The findings help for a better understanding of local contact characteristics and its relevance. The quantified scale effects help to improve the efficiency and load-carrying capacity of machine elements with hard conformal EHL contacts, like internal gearings.

The peer review history for this article is available at: https://publons.com/publon/10.1108/ILT-12-2022-0366/

An unprecedented scale of human migration has lead humanitarians to view camps as long-term settlements rather than temporary holding facilities. The purpose of this paper is to increase the understanding of and identify challenges with this proposed new approach to camp design.

Based on the camp design literature, the authors developed an interview guide and checklist for data collection. A multi-site case study and within- and cross-case analysis was then conducted.

The findings suggest that the proposed new approach is implemented only to a limited extent, and mostly in a stepwise manner. As camps mature, there is a shift toward the new approach, but most camps are established using the traditional top-down, temporary, and isolated approach.

The findings are based on four camps in four different countries and do not provide an exhaustive global coverage.

The insights the authors derived and the challenges identified from the empirical evidence can be used to better plan future camps.

The results can support improvements in camp design, thus alleviating suffering for both refugees and host communities, particularly in developing countries. In particular, the trade-off between a permanent solution and the temporary must be accounted for.

The study contributes to the literature by developing and proposing a conceptual framework to camp design. The cross-case analysis provides an initial understanding and categorization of challenges with implementing the new approach. It also suggests an evolutionary perspective of camp design.

The purpose of this paper is to estimate the years the European Muslim population will be majority among 30 European countries.

The methodology/approach is to forecast the population of 30 European countries with wavelet analysis combined with the Burg model which fits a pth order autoregressive model to the input signal by minimizing (least squares) the forward and backward prediction errors while constraining the autoregressive parameters to satisfy the Levinson–Durbin recursion, then relies on an infinite impulse response prediction error filter. Three scenarios are considered: the zero-migration scenario where the authors assume that the Muslim population has a higher fertility (one child more per woman, on average) than other Europeans, mirroring a global pattern; a 2017 migration scenario: to the Muslim population obtained in the zero-migration scenario, the authors add a continuous flow of migrants every year based on year 2017; the mid-point migration scenario is obtained by averaging the data of the two previous scenarios.

Among three scenarios, the most likely mid-point migration scenario identifies 13 countries where the Muslim population will be majority between years 2085 and 2215: Cyprus (in year 2085), Sweden (2125), France (2135), Greece (2135), Belgium (2140), Bulgaria (2140), Italy (2175), Luxembourg (2175), the UK (2180), Slovenia (2190), Switzerland (2195), Ireland (2200) and Lithuania (2215). The 17 remaining countries will never reach majority in the next 200 years.

The growing Muslim population will change the face of Europe socially, politically and economically. This paper will provide a better insight and understanding of Muslim population dynamics to European governments, policymakers, as well as social and economic planners.

The purpose of this paper is to consider the social turn in contemporary capitalism and contemporary art through the lens of art-based social enterprises (ASEs) that aim to create positive social benefits for young people experiencing forms of marginalisation, and which trade creative products or services to help fulfil that mission. A growth in ASEs demonstrates a growing interest in how the arts can support social and economic development, and the ways new economic models can generate employment for individuals excluded from the labour market; extend opportunities for more people to participate in art markets; and challenge dominant market models of cultural production and consumption.

This paper considers a number of challenges and complexities faced by ASEs that embrace a co-dependence of three goals, which are often in tension and competition – artistic practice, social purpose and economic activity. It does so by analysing interviews from staff working with 12 ASE organisation’s across Australia.

While the external forces that shape ASEs – including government policy, markets, investors and philanthropy – are interested in the “self-sufficient” economic potential of ASEs, those working in ASEs tend to prioritise social values and ethical business over large financial returns and are often ambivalent about their roles as entrepreneurs. This ambivalence is symptomatic of a position that is simultaneously critical and affirmative, of the conditions of contemporary capitalism and neoliberalism.

This paper addresses a gap in social enterprise literature presenting empirical research focussing on the lived experience of those managing and leading ASEs in Australia.