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Clinical staff working in mental health services experience high levels of work-related stress, burnout and poor well-being. Increased levels of stress, burnout, depression and anxiety and poorer mental well-being among health-care workers are associated with more sick days, absenteeism, lower work satisfaction, increased staff turnover and reduced quality of patient care. Virtual reality (VR) relaxation is a technique whereby experiences of pleasant and calming environments are accessed through a head-mounted display to promote relaxation. The purpose of this paper is to describe the design of a study that assesses the feasibility and acceptability of implementing a multi-session VR relaxation intervention amongst mental health professionals, to improve their relaxation levels and mental well-being.

The study follows a pre–post-test design. Mental health staff will be recruited for five weeks of VR relaxation. The authors will measure the feasibility and acceptability of the VR relaxation intervention as primary outcomes, alongside secondary outcomes evaluating the benefits of VR relaxation for mental well-being.

The study aims to recruit 20–25 health-care professionals working in both inpatient and specialist community mental health settings.

Research indicates the potential of VR relaxation as a low-intensity intervention to promote relaxation and reduce stress in the workplace. If VR relaxation is shown to be feasible and acceptable, when delivered across multiple sessions, there would be scope for large-scale work to investigate its effectiveness as an approach to enable health-care professionals to de-stress, relax and optimise their mental well-being. In turn, this may consequently reduce turnover and improve stress-related sick leave across health-care services.

The purpose of this paper is to propose a warranty-based bilateral automated multi-issue negotiation approach.

A methodology for bilateral automated negotiation process is developed considering the targets such as warranty attractiveness, warranty cost, mean time between failures, spare parts cost to the end user over the useful life of the life. The negotiation methodology is explained using different cases of negotiation. The optimization for each negotiation step is carried out using genetic algorithm with elitism strategy.

The result after optimization indicates that the desired target values are achieved and manufacturer obtained desired profit margin.

Application of automated negotiation model is illustrated using a real life case of an automobile engine manufacturer. The proposed approach helps the manufacturer of any product to develop a methodology for carrying out the negotiation process. The approach also results into taking warranty-related decisions at the design stage.

This paper contributes in proposing a generalized methodology for warranty-based negotiation in which the negotiation is carried out between the manufacturer and the customer.

This paper aims to discuss the dynamic adsorption processes of carbon dioxide in a porous fixed bed on the industrial scale, using a multiple-relaxation-time lattice Boltzmann (LB) model.

A multiple-relaxation-time LB model is developed to predict the dynamic adsorption processes of carbon dioxide in a porous fixed bed on the industrial scale. The breakthrough curves from the simulation results are compared with the experimental data to validate the reliability of this model, and the effects of flow velocity, porosity and linear driving force mass transfer coefficient on the adsorption behaviors of carbon dioxide are explored further.

The numerical results show that the improved fluid flux leads to the reduction in the time required for completion of adsorption processes nonlinearly, and the differential pressure significantly raises with the decreasing porosity of porous fixed bed for fixed values of Reynolds number and total adsorption capacity. The maximum adsorption ratio of carbon dioxide was found at Re = 12 in this work. In addition, the higher mass transfer resistance of adsorbent particles advances the appearance time of the breakthrough point and delays the completion time of the adsorption processes.

This work will provide a way to study the adsorption technology of carbon dioxide in the fixed-bed using the LB method.

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 paper aims to expand the scope of application of the lattice Boltzmann method (LBM), especially in the field of aircraft engineering. The traditional LBM is usually applied to incompressible flows at a low Reynolds number, which is not sufficient to satisfy the needs of aircraft engineering. Devoted to tackling the defect, the paper proposes a developed LBM combining the subgrid model and the multiple relaxation time (MRT) approach. A multilayer adaptive Cartesian grid method to improve the computing efficiency of the traditional LBM is also employed.

The subgrid model and the multilayer adaptive Cartesian grid are introduced into MRT-LBM for simulations of incompressible flows at a high Reynolds number. Validated by several typical flow simulations, the numerical methods in this paper can efficiently study the flows under high Reynolds numbers.

Some numerical simulations for the lid-driven flow of cavity, flow around iced GLC305, LB606b and ONERA-M6 are completed. The paper presents the investigation results, indicating that the methods are accurate and effective for the separated flow after icing.

LBM is developed with the addition of the subgrid model and the MRT method. A numerical strategy is proposed using a multilayer adaptive Cartesian grid method and its treatment of boundary conditions. The paper refers to innovative algorithm developments and applications to the aircraft engineering, especially for iced wing simulations with flow separations.

This paper aims to demonstrate the capabilities of a diffuse interface free energy lattice Boltzmann method to perform direct numerical simulations of liquid–liquid dispersions in a well-controlled turbulent environment. The goal of this research study is to develop numerical techniques that can visualize and quantify drop interaction with the turbulent vortices. The obtained information will be used for the development of sub-models of drop breakup for multi-scale simulations.

A pure binary liquid system is considered that is subject to fully developed statistically stationary turbulent flow field in a cubic fully periodic box with the edge size of 300 lattice units. Three turbulent flow fields with varying energy input are examined and their coherent structures are visualized using a normalized Q-criterion. The evolution of the liquid–liquid interface is tracked as a function of time. The detailed explanation of the numerical method is provided with a highlight on a choice of the numerical parameters.

Drop breakup mechanisms differ depending on energy input. Drops break due to interaction with the vortices. Quantification of turbulent structures shows that the size of vortices increases with the decrease of energy input. Drop interacts simultaneously with multiple vortices of the size comparable to or smaller than the drop size. Vortices of the size smaller than the drop size disturb drop interface and pinch off the satellites. Vortices of the size comparable to the drop size tend to elongate the drop and tear it apart producing daughter drops and satellites. Addition of the second phase enhances turbulent dissipation at the high wavenumbers. To obtain physically realistic two-phase energy spectra, the multiple-relaxation-time collision operator should be used.

Detailed information of drop breakup in the turbulent flow field is crucial for the development of drop breakup sub-models that are necessary for multi-scale numerical simulations. The improvement of numerical methods that can provide these data and produce reliable results is important. This work made one step towards a better understanding of how drops interact with the turbulent vortices.

This study aims to modify the standard probabilistic lattice Boltzmann methodology (LBM) cellular automata (CA) algorithm to enable a more realistic and accurate computation of the ensemble rather than individual particle trajectories that need to be updated from one time step to the next (allowing, as such, a fraction of the collection of particles in any lattice grid cell to be updated in a time step, rather than the entire collection of particles as in the standard LBM-CA algorithm leading to a better representation of the dynamic interaction between the particles and the background flow). Exploitation of the inherent parallelism of the modified LBM-CA algorithm to provide a computationally efficient scheme for computation of particle-laden flows on readily available commodity general-purpose graphics processing units (GPGPUs).

This paper presents a framework for the implementation of a LBM for the simulation of particle transport and deposition in complex flows on a GPGPU. Towards this objective, the authors have shown how to map the data structure of the LBM with a multiple-relaxation-time (MRT) collision operator and the Smagorinsky subgrid-scale turbulence model (for turbulent fluid flow simulations) coupled with a CA probabilistic method (for particle transport and deposition simulations) to a GPGPU to give a high-performance computing tool for the calculation of particle-laden flows.

A fluid-particle simulation using our LBM-MRT-CA algorithm run on a single GPGPU was 160 times as computationally efficient as the same algorithm run on a single CPU.

The method is limited by the available computational resources (e.g. GPU memory size).

A new 3D LBM-MRT-CA model was developed to simulate the particle transport and deposition in complex laminar and turbulent flows with different hydrodynamic characteristics (e.g. vortex shedding, impingement, free shear layer, turbulent boundary layer). The solid particle information is encapsulated locally at the lattice grid nodes, allowing for straightforward mapping of the datastructure onto a GPGPU enabling a massive parallel execution of the LBM-MRT-CA algorithm. The new particle transport algorithm was based on the local (bulk) particle density and velocity and provides more realistic results for the particle transport and deposition than the standard LBM-CA algorithm.

The purpose of this paper is to investigate the natural convection behavior of nanofluids in an enclosure. The enclosure is a 3D capsule with curved boundaries filled with TiO₂-water nanofluid.

In this paper, a multiple relaxation times lattice Boltzmann method (MRT-LBM) has been used. Two-component LBM has been conducted to consider the interaction forces between nanoparticles and the base fluid.

Results show that the enhanced Nusselt number (Nu*) increases with the increase in volume fraction of nanoparticles (ϕ) and Ra number and decrease of nanoparticle size (λ). Additionally, the findings indicate that increasing volume fraction beyond a certain value decreases Nu*.

This paper presents a MRT model of lattice Boltzmann in a 3D curved enclosure. A correlation is also presented based on the current results for Nu* depending on Ra number, volume fraction and size of nanoparticles. Furthermore, a comparison for the convergence rate and accuracy of this model and the SIMPLE algorithm is presented.

The purpose of this paper is to test an efficiency algorithm based on lattice Boltzmann method (LBM) and using it to analyze two-dimensional natural convection with low Prandtl number.

Steady state or oscillatory results are obtained using double multiple-relaxation-time thermal LBM. The velocity and temperature fields are solved using D2Q9 and D2Q5 models, respectively.

With different Rayleigh number, the tested natural convection can either achieve to steady state or oscillatory. With fixed Rayleigh number, lower Prandtl number leads to a weaker convection effect, longer oscillation period and higher oscillation amplitude for the cases reaching oscillatory solutions. At fixed Prandtl number, higher Rayleigh number leads to a more notable convection effect and longer oscillation period.

Double multiple-relaxation-time thermal LBM is applied to simulate the low Prandtl number (0.001-0.01) fluid natural convection. Rayleigh number and Prandtl number effects are also investigated when the natural convection results oscillate.

Natural convection heat transfer during free convection phenomenon in a cavity included with active fins and pipes is investigated. The influence of the orientation of fins on the heat transfer between heat source (i.e. hot fins) and heat sink (i.e. cold pipes) is investigated by using numerical and experimental techniques.

For the numerical simulations, the multiple relaxation time (MRT) thermal lattice Boltzmann method (LBM) is used. In this numerical approach, two separated distribution functions are used to solve the flow and temperature distributions within the computational domain. Furthermore, the local/volumetric second law analysis is used to show the impact of evaluated parameters on the heat transfer irreversibility. In addition, the dynamic viscosity and thermal conductivity of TiO2-water nanofluid are measured by using Brookfield viscometer and KD2 pro conductmeter, respectively.

The examined range of Rayleigh number is from 103 to 106, and the nanofluid samples are provided in 0, 20, 40, 60, 80 and 100 ppm.

The originality of this work is use of dual-MRT thermal LBM and experimental measurements of rheological/thermal properties of nanofluid for investigation of free convection problem for the considered application.