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The paper targets on providing new experimental data for validation of the well-established mathematical models within the framework of the lattice Boltzmann method (LBM), which are applied to problems of casting processes in complex mould cavities.

An experimental campaign aiming at the free-surface flow within a system of narrow channels is designed and executed under well-controlled laboratory conditions. An in-house lattice Boltzmann solver is implemented. Its algorithm is described in detail and its performance is tested thoroughly using both the newly recorded experimental data and well-known analytical benchmark tests.

The benchmark tests prove the ability of the implemented algorithm to provide a reliable solution when the surface tension effects become dominant. The convergence of the implemented method is assessed. The two new experimentally studied problems are resolved well by simulations using a coarse computational grid.

A detailed set of original experimental data for validation of computational schemes for simulations of free-surface gravity-driven flow within a system of narrow channels is presented.

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.

Posttraumatic stress disorder (PTSD), an anxiety disorder with lifetime prevalence of 7.8%, is characterized by symptoms that develop following exposure to traumatic life events and that cause an immediate experience of intense fear, helplessness or horror. PTSD is marked by recurrent nightmares typified by the recall of intrusive experiences and by extended disturbance throughout sleep. Individuals with PTSD respond poorly to drug treatments for insomnia. The disadvantages of drug treatment for insomnia underline the importance of non-pharmacological alternatives. Thus, the present study had three aims: first, to compare the efficiency of two relaxation techniques (muscular relaxation and progressive music relaxation) in alleviating insomnia among individuals with PTSD using both objective and subjective measures of sleep quality; second, to examine whether these two techniques have different effects on psychological indicators of PTSD, such as depression and anxiety; and finally, to examine how initial PTSD symptom severity and baseline emotional measures are related to the efficiency of these two relaxation methods. Thirteen PTSD patients with no other major psychiatric or neurological disorders participated in the study. The study comprised one seven-day running-in, no-treatment period, followed by two seven-day experimental periods. The treatments constituted either music relaxation or muscle relaxation techniques at desired bedtime. These treatments were randomly assigned. During each of these three experimental periods, subjects' sleep was continuously monitored with a wrist actigraph (Ambulatory Monitoring, Inc.), and subjects were asked to fill out several questionnaires concerned with a wide spectrum of issues, such as sleep, depression, and anxiety. Analyses revealed a significant increase in objective and subjective sleep efficiency and a significant reduction in depression level following music relaxation. Moreover, following music relaxation, a highly significant negative correlation was found between improvement in objective sleep efficiency and reduction in depression scale. The study‘s findings provide evidence that music relaxation at bedtime can be used as treatment for insomnia among individuals with PTSD.

The purpose of this paper is to present a fast and bare bones implementation of a numerical method for quickly simulating turbulent thermal flows on GPUs. The work also validates earlier research showing that the lattice Boltzmann method (LBM) method is suitable for complex thermal flows.

A dual lattice hydrodynamic (D3Q27) thermal (D3Q7) multiple-relaxation time LBM model capable of thermal DNS calculations is implemented in CUDA.

The model has the same computational performance compared to earlier publications of similar LBM solvers. The solver is validated against three benchmark cases for turbulent thermal flow with available data and is shown to be in excellent agreement.

The combination of a D3Q27 and D3Q7 stencil for a multiple relaxation time -LBM has, to the authors’ knowledge, not been used for simulations of thermal flows. The code is made available in a public repository under a free license.

The purpose of this study is to investigate the effectiveness of online self-leadership training (OSLT) in promoting leaders’ self-leadership skills and recovery experiences.

A non-randomized controlled trial was conducted under two conditions: a standardized seven-week OSLT (N = 43) and a control without any intervention (N = 42). All participants (N = 85) completed standardized questionnaires measuring self-reported self-leadership skills and recovery experiences. Additionally, participants in the intervention group were assigned to invite one team member each (N = 26) to assess their leaders’ pre-post self-leadership skills and pre-post leader–member exchange.

Significant interaction effects of time and group and increases in the OSLT group (t1 vs t2) in self-leadership skills (cognitive and natural reward strategies) and recovery experiences (detachment and relaxation) indicated the effectiveness of OSLT training. Significant improvements in self-leadership skills and leader–member exchange were reported by team members of leaders in the OSLT group.

To the best of the authors’ knowledge, this study was the first to examine the effectiveness of OSLT for leaders in business contexts in a controlled before-after intervention design. The findings of this study revealed improvements in self-leadership skills and recovery experience because of OSLT.

To gain insight into factors enhancing or obstructing implementation in various school-settings, which is vital for widespread dissemination and sustainable integration of school-based health-promoting interventions.

A mixed methods multisite comparative case study to investigate (factors influencing) the implementation of health-promoting activities in twelve Dutch primary schools. Data were collected during three school years (2019–2022) through observations, questionnaires and interviews.

The project resulted in the implementation of small, incidental activities. Important reasons for the limited implementation were lack of commitment and bottom-up involvement. School directors and teachers were not involved early on in the project, which limited project support and commitment. On school level, directors largely carried project responsibility themselves, hindering project sustainability and integration. Coronavirus disease 2019 (COVID-19) made that schools had difficulties forming long-term visions and plans. Other observed barriers included limited perceived necessity to change, high workload and high staff turnover. Important facilitators were the presence of a process coordinator and sharing experiences from other schools.

This research provided valuable insights into (factors influencing) the implementation of health-promoting initiatives in diverse, real-world school contexts. More extensive support is needed to create commitment, bottom-up involvement and a project vision. Furthermore, empowering in-school champions and/or school-wide project groups is desirable to decrease schools' dependence on long-term external support. The findings can be used by various stakeholders throughout development, adoption and implementation and can facilitate widespread dissemination and sustainable integration of school-based health-promoting interventions.

The purpose of this paper is to investigate the overall campaign reach and impact of the ABCs of Mental Health in Denmark; a secondary objective is to investigate how mental health-promoting beliefs and actions are associated with good mental health.

A questionnaire was administered to two representative cross-sectional samples of the Danish population (1,508 respondents in 2019; 1,507 respondents in 2021) via an online survey. The data were subsequently pooled together into one sample consisting of 3,015 respondents. In addition to questions pertaining to campaign reach and impact, the questionnaire also included a validated scale for mental well-being and questions about beliefs and actions in regard to enhancing mental health.

About 7.6% had been reached by the campaign (familiar with ABC name or messages), or 11.9% when also counting familiarity with campaign slogans. Among these, respondents reported (proportions in parentheses) that the campaign had 1) made them reflect on their mental health (74.2%), talk to friends and family about mental health (35.5%), given them new knowledge about what they can do to enhance mental health (78.4%), or take action to enhance their own mental health (16.2%). An internal well-being locus of control and proactive behaviours towards enhancing mental health are shown to be associated with higher mean scores on mental well-being, lower odds of low mental well-being and higher odds of higher mental well-being.

An internal well-being locus of control and proactive behaviours towards enhancing mental health are suggested to both prevent low levels of mental well-being and promoting high levels of mental well-being. The results indicate that the ABCs of Mental Health campaign may be implemented to promote such beliefs and actions universally throughout the population.

The purpose of the paper is to predict the aerodynamic performance of a complete scale model H-Darrieus vertical axis wind turbine (VAWT) with end plates at different operating conditions. This paper aims at understanding the flow physics around a model VAWT for three different tip speed ratios corresponding to three different flow regimes.

This study achieves a first three-dimensional hybrid lattice Boltzmann method/very large eddy simulation (LBM-VLES) model for a complete scaled model VAWT with end plates and mast using the solver PowerFLOW. The power curve predicted from the numerical simulations is compared with the experimental data collected at Erlangen University. This study highlights the complexity of the turbulent flow features that are seen at three different operational regimes of the turbine using instantaneous flow structures, mean velocity, pressure iso-contours, blade loading and skin friction plots.

The power curve predicted using the LBM-VLES approach and setup provides a good overall match with the experimental power curve, with the peak and drop after the operational point being captured. Variable turbulent flow structures are seen over the azimuthal revolution that depends on the tip speed ratio (TSR). Significant dynamic stall structures are seen in the upwind phase and at the end of the downwind phase of rotation in the deep stall regime. Strong blade wake interactions and turbulent flow structures are seen inside the rotor at higher TSRs.

The computational cost and time for such high-fidelity simulations using the LBM-VLES remains expensive. Each simulation requires around a week using supercomputing facilities. Further studies need to be performed to improve analytical VAWT models using inputs/calibration from high fidelity simulation databases. As a future work, the impact of turbulent and nonuniform inflow conditions that are more representative of a typical urban environment also needs to be investigated.

The LBM methodology is shown to be a reliable approach for VAWT power prediction. Dynamic stall and blade wake interactions reduce the aerodynamic performance of a VAWT. An ideal operation close to the peak of the power curve should be favored based on the local wind resource, as this point exhibits a smoother variation of forces improving operational performance. The 3D flow features also exhibit a significant wake asymmetry that could impact the optimal layout of VAWT clusters to increase their power density. The present work also highlights the importance of 3D simulations of the complete model including the support structures such as end plates and mast.

Accurate predictions of power performance for Darrieus VAWTs could help in better siting of wind turbines thus improving return of investment and reducing levelized cost of energy. It could promote the development of onsite electricity generation, especially for industrial sites/urban areas and renew interest for VAWT wind farms.

A first high-fidelity simulation of a complete VAWT with end plates and supporting structures has been performed using the LBM approach and compared with experimental data. The 3D flow physics has been analyzed at different operating regimes of the turbine. These physical insights and prediction capabilities of this approach could be useful for commercial VAWT manufacturers.

The purpose of this paper is to examine the coffee culture of citizens of Southern Nigeria. Specifically, different scales were developed to measure coffee culture among the citizens which cover health, socialisation, elitism, culture and commercialisation factors.

A quantitative approach was adopted for the study, and factor analysis was used to analyse the data collected through an online survey. As a result, EFA and CFA showed the test of sphericity and the different fit indexes.

The findings revealed the experiences of consumers and their disposition to coffee consumption to establish coffee culture among the citizens. Largely, the findings revealed that coffee culture is still very low among the citizens and the summation that coffee culture is still in infancy.

Given the importance of coffee culture in the larger world, and acceptance of coffee as a global social drink, the design of a scale that focussed on socialisation, health, elitism, culture and commercialisation factors help to robustly investigate the state of coffee culture among the citizens.

This paper aims to present a requirements analysis for the processing of water-based electrode dispersions in inkjet printing.

A detailed examination of the components and the associated properties of the electrode dispersions has been carried out. The requirements of the printing process and the resulting performance characteristics of the electrode dispersions were analyzed in a top–down approach. The product and process side were compared, and the target specifications of the dispersion components were derived.

Target ranges have been identified for the main component properties, balancing the partly conflicting goals between the product and the process requirements.

The findings are expected to assist with the formulation of electrode dispersions as printing inks.

Little knowledge is available regarding the particular requirements arising from the systematic qualification of aqueous electrode dispersions for inkjet printing. This paper addresses these requirements, covering both product and process specifications.