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Thin-walled tubular deployable composite boom (DCB) has gained significant attention due to its lightweight, simple structure and high packaging efficiency. The experimental and numerical simulation methods were employed in this paper to investigate the folding behavior of the DCB. Using T700/epoxy unidirectional reinforced prepreg as raw material, DCB specimens were prepared by the vacuum bag method. To complete the folding experiments of DCB specimens, a folding mechanism was designed and manufactured. Folding experiments of DCB specimens were conducted and folding moment versus rotational displacement curves were measured. In addition, a Finite Element Model (FEM) was established to predict the folding behavior of the DCB. Different failure criteria were considered in the numerical analysis, including the Tsai‐Hill criterion and maximum stress criterion. Prediction results using the FEM were compared with experimental results, and both sets of results were in good agreement. It is shown that the DCB can achieve the folding function without failure. The research results in this paper are of great significance to the practical engineering application of the DCB. [Display omitted] • Six tubular deployable composite boom specimens and a precise folding mechanism were designed and prepared. • Folding experiments were conducted to measure the folding moment and rotational displacement curves. • A finite element model for predicting the folding behavior of the tubular deployable composite boom was established. [ABSTRACT FROM AUTHOR]

Hydrothermal treatment of sludge within the pulp and paper industry can have a wide range of possible reactor solid loads for different sludge types. The objectives of this work were to determine the effect of reactor temperature and solid load on the properties of sludge hydrochar and to simulate hydrothermal treatment of sludge within a pulp and paper mill. Laboratory experiments were first performed within reactor temperature and solid load ranges of 180–260 °C and 10–50%, respectively, and the effects of sludge treatment were determined by comparing parallel mill-scale simulations. Based on the results, both reactor temperature and solid load had a statistically significant effect on the solid, ash, carbon and energy yields of sludge hydrochar. Increasing solid load minimized carbon dissolution to the liquid phase and increased the solid and energy yield of the attained hydrochar. According to mill-scale simulations in a 9 m 3 batch reactor, treating primary sludge alone produced an energy surplus of 22–36 GJ through char incineration, decreasing to 12–22 GJ and 3.4–9.1 GJ for mixed and secondary sludge, respectively. Mixing primary and secondary sludge reduced the overall energy surplus by 2–8% compared with treating the sludge streams separately in two reactors. [ABSTRACT FROM AUTHOR]

Highlights • Paper-based thin sample layer ion transfer voltammetry was realized. • Linear scan voltammetry was chosen to investigate the electrochemical behavior. • Electrochemical behavior are compared to numerical simulation. • Background corrections can be used to eliminate undesired interference. Abstract We report here on paper-supported thin sample layer voltammetry for the determination of ions. To achieve this goal, a simple setup for the coupling of a commercially available electrode to a silver rod electrode was designed and evaluated for paper-supported thin-layer voltammetry. Linear scan ion transfer voltammetry was explored here for ion-selective membranes doped with an ionophore. The ion-transfer processes and electrochemical behaviors of the system are here evaluated and confirmed by numerical simulation. In the proof-of-concept experiments described, the ions tetrabutylammonium chloride (TBA+) and potassium (K+) were studied as model analytes at membranes without and with ionophore, respectively. A linear relationship from 0.1 mM to 1.0 mM K+ was obtained between the charge and ion concentration. The coexistence of background sodium ions did not give appreciable interference, but the background wave was not completely isolated from the analyte wave, as also confirmed by the model. The methodology was successfully demonstrated for determination of K+ in mineral water. It is anticipated that this paper-supported thin-layer detection approach may provide an attractive readout protocol for disposable paper-based analytical devices as the methodology does not place strict demands on reference electrode performance. [ABSTRACT FROM AUTHOR]

Abstract A number of problems associated with dimensional stability of paper products have to do with hygroexpansion in response to changes in humidity or moisture content. The main underlying mechanism of hygroexpansion in paper is the effect of the change of fiber cross-sections transferred through fiber bonds. In fact, the transverse expansion of fibers can be an order of magnitude greater than the longitudinal expansion. Addressing such problems using modeling on the microscale is associated with large computational costs since both the bonds and the fibers need to be resolved. We present a method for modeling the hygro or thermal expansion of interconnected fiber networks modeled with beam elements and connected through beam-to-beam contact. Being a line structure, beams can only support pointwise contact, which poses a challenge for modeling the force transfer induced by the deformation of the cross-sections at the contact point. The idea of implementing the stress transfer is to use a concurrent multiscale approach in which the bond level is resolved in detail using the configuration of the fibers and the computed strains are passed over to the beam elements. We verify and prove the applicability of this approach by comparing it with continuum models. We demonstrate the advantage of using this approach in terms of its tremendous saving in time. The use of beam models for modeling the hygro- or thermal expansion of fiber networks enables considering relevant sizes in the problems involving dimensional stability, in particular those associated with embedded inhomogeneities. We will show the applicability of the model by providing insights into published experimental observations on the hygroexpansion properties of paper products. Finally, we will demonstrate that the use of a 2D model to simulate the inter-fiber bonds in a network, not only leads to underestimation of out-of-plane deformations, but also to overestimation of the contribution of the transverse deformation of fibers to the in-plane dimensional change of the network. [ABSTRACT FROM AUTHOR]

Hydrogen is an ideal energy source and plays an important role in increasingly global energy issues and environmental problems. Liquid hydrogen (LH2) has many advantages over other storage methods, especially in terms of energy density. However, it may cause enormous harm once it leaks accidently. LH2 leakage is a complex multiphase process involving evaporation, condensation, transfer of mass and heat, and dispersion. In order to study LH2 transportation and storage systems safety, a research project has been carried out to develop a 3D numerical model using an open-source CFD code, OpenFoam, for investigating LH2 accidental release scenarios. Since the release of LH2 is a very complex process, our strategy is to study it step by step. Therefore, in this paper we present our research work at the first stage, a dispersion process of room-temperature gaseous hydrogen without multiphase flow. A small-scale hydrogen release conducted by Sandia National Laboratories is simulated. In this experiment, room-temperature gaseous hydrogen is injected upwards into the air from a small hole with a 1.91 mm diameter. The situations of Froude (Fr) number = 99, 152, and 268 are studied, respectively. The behavior of hydrogen at different Fr numbers is discussed. When high-speed hydrogen enters the air, the speed and concentration of hydrogen decrease rapidly. In addition, the greater the speed, the faster it decays. The result shows a close range of hydrogen reach. Details about the numerical model are introduced. The simulation results are used to verify the validity of the developing numerical model for dispersion and mixing of multi-species. The simulated concentrations and velocity distribution are analyzed and compared with experimental data. The simulation shows a good agreement with the data of Sandia National Laboratories. The agreement between experiments and simulations is measured using the Pearson correlation coefficient (>0.98), which indicates excellent consistency. In the next step, we will integrate the multiphase flow and phase change into the current model. The phase change of liquid hydrogen and air will be simulated to study the release of liquid hydrogen. • Using the open-source CFD code OpenFOAM for simulation of hydrogen jet. • A good agreement between the simulations results and experimental data has been found in this paper. • When high-speed hydrogen is injected into the air, both velocity and concentration drop rapidly. • Final concentration is not sensitive to different injection velocity. [ABSTRACT FROM AUTHOR]

This paper employs a numerical approach to investigate the impact of liquidity shocks on European options in modeling markets. To accurately capture the behavior of European options under liquidity shocks, a coupled system of differential equations is employed, consisting of a degenerate parabolic equation and a diffusion-free equation. The primary focus is on developing and analyzing implicit-explicit methods for numerically simulating European option pricing, specifically considering the presence of liquidity shocks while ensuring the positivity of the solution. The paper also includes convergence analysis and establishes the discrete comparison principle for the developed methods. Numerical experiments are conducted using both uniform and nonuniform meshes to validate the theoretical findings, demonstrating the efficiency and accuracy of the proposed methods. [ABSTRACT FROM AUTHOR]

Some errors exist in the above paper. [ABSTRACT FROM AUTHOR]

The Lennard-Jones (LJ) fluid, named after mathematician-physicist-chemist Sir John Lennard-Jones (1894–1954), occupies a special place among fluids. It is an ideal entity, defined as the fluid whose particles interact according to the Lennard-Jones potential. This paper expounds the history of the LJ fluid to throw light on the tensions between theory and computational practice. The paper argues for the following claims. Firstly, the computational approach—even prior to the computer—pragmatically aims at prediction, not truth. Secondly, computer simulation methods, especially "molecular dynamics" (MD), triggered a change in epistemology. Now, simulated model fluids became targets of investigation in their own right. The urge for prediction turned the LJ fluid into the most investigated fluid in engineering thermodynamics. Thirdly, MD took a huge upswing in the 1990s, due to exploratory options in simulation. We discuss how, under these conditions, predictive success might be fraught with problems of reproducibility. [ABSTRACT FROM AUTHOR]

In this study, a computer model based on discrete element method is employed to simulate the unsteady state heat transfer from the fuser roll to the toner and coating layer during the Xerography printing of coated papers. The model coating layers consisted of randomly arranged spherical pigment and latex particles with commercially relevant size distributions. Effects of coating characteristics, toner size, multiple toner layers, toner melting energy, toner thermal conductivity, coating layer thermal conductivity, and fuser roll temperature and pressure were investigated. Iso-thermal contours of fusing time were generated to demonstrate the relative importance of different fusing conditions and toner properties. Simulation results showed that temperature variation highly depended on the toner size, toner melting energy and the fuser roll temperature. Moreover, simultaneous coupling of the compressive stress and heat transfer indicated that the pressure exerted by the fuser roll did not significantly affect the rate of heat transfer. [Copyright &y& Elsevier]

• Numerically investigate folding pattern and rigid-flexible coupled dynamics of satellite-sphere system. • Achieve a larger volume folding rate by pattern of inflatable sphere with orderly deployment. • Inflating process has great influence on satellite based on rigid-flexible coupled dynamic model. • Reduce influence by heavier satellite, small inflation rate and appropriate control torque. Inflatable spheres can be applied to the aerodynamic drag deorbiting device for satellites. It may bring about a complicated dynamic problem under the disturbance from the lightweight large-volume inflatable sphere to the satellite. In order to explore this problem, rigid-flexible coupled dynamics behaviors of satellite-sphere system during inflating process are numerically studied in this paper. The folding pattern of inflatable sphere is designed to obtain the parametric model in the folded state. The dynamic analysis model of this system is established to analyze dynamic behaviors, including the dynamics of the satellite-sphere system, the gas state of the airbag and the disturbance to the satellite, during the inflating process. Parameter effects on the attitude disturbance are studied. The results show that the satellite mass, inflating mass rate and control torque have a great impact on the attitude disturbance. These works provide theoretical bases and technical supports for the engineering development of inflatable sphere deorbiting devices. [ABSTRACT FROM AUTHOR]

On-orbit capturing is a crucial step in the application of dual-arm space robots, aiming to accurately grasp a moving target and avoid damage to the arms terminal parts (i.e. the end effectors) due to contact force saturation. This paper presents a synthetic control method with target sticking for on-orbit capturing using a dual-arm space robot system from the approaching phase to pre-grasping phase. In the approaching phase, an online trajectory planning method based on visual servoing is proposed to obtain the desired trajectories for end effectors in work space. Then the joint torques are designed by the inverse kinematics and inverse dynamics to track the desired trajectories. Different from most of the current research, a new sticking phase is proposed after the approaching phase and before the pre-grasping phase. In the sticking phase, a force and motion control method is designed to maintain a close relative distance between end effectors and the target, which can avoid saturation of contact forces and avoid damage to the end effectors. In what follows, an impedance control method is proposed in the pre-grasping phase to absorb the impact energy and grasp the target accurately. The synthetic control strategy integrates the controllers of all the phases mentioned above. Automatic switching among the phases is realized by using logic judgment according to the system real states, which is more consistent with the real capturing environment. Finally, numerical simulation results demonstrate the effectiveness of the proposed synthetic control scheme. The results can be applied to the trajectory planning and control of on-orbit capturing, avoiding contact force saturation and ensuring the safety of the system. [ABSTRACT FROM AUTHOR]

Nonlocal problems involving fourth-order terms pose several difficulties such as numerical discretization and its related convergences analysis. In this paper, the well-posedness of the extended Fisher-Kolmogorov equation with nonlocal diffusion is first analyzed using the Faedo-Galerkin technique and the classical compactness arguments. Moreover, we adopt a BDF2 scheme for time discretization and a mixed Galerkin scheme for spatial discretization. Then, we derive the optimal order convergence rates of the fully discrete system. Finally, some numerical simulations and convergence results are provided to confirm the theoretical results and the accuracy of the proposed scheme. [ABSTRACT FROM AUTHOR]

Hydrogen is considered a truly clean energy source with great potential for replacing fossil fuels. However, the special physical and chemical properties of this source make large-scale, safe, and efficient storage challenging, thus limiting its widespread use. Consequently, an underground hydrogen storage system inspired by underground methane storage and CO 2 geological sequestration has been proposed, and it is increasingly becoming a focus of research. Depleted oil reservoirs are ideal sites for such systems. Nevertheless, research on these types of underground hydrogen storage systems is limited to a few feasibility assessments, and the hydrogen seepage laws in reservoirs with residual oil are not well understood. In this paper, a study was conducted involving mathematical modeling and numerical simulation of underground hydrogen storage, which was converted from the SSZ low-permeability depleted oil reservoir in Bohaiwan Basin, eastern China, to reveal the seepage patterns between hydrogen and complicated in situ fluids (oil, gas, and water). First, a comprehensive analysis was conducted using numerous rock samples and experimental data to identify the composition, genesis, and distribution patterns of the sandstone reservoir, detailing its internal pore structure and fluid distribution postdepletion characteristics. Then, the hydrogen seepage properties in the presence of oil films in the three main throat types of low-permeability sandstone were analyzed, and corresponding mathematical models of the different throats were established. Finally, a numerical simulation of underground hydrogen storage was conducted to assess the impacts of various parameters, such as injection speed, reservoir heterogeneity, and residual oil saturation, on hydrogen seepage. The planar and vertical diffusion patterns of hydrogen were clarified, and the key factors affecting the efficiency of underground hydrogen storage were analyzed, offering suggestions for the establishment of stable and efficient underground hydrogen storage systems. • Selection and description of typical low-permeability reservoirs for UHS. • Mathematical model establishment for hydrogen percolation in porous rock. • Numerical simulation of the storage process of hydrogen. • Percolation laws of hydrogen in rock porous. [ABSTRACT FROM AUTHOR]

Advancements in bulk metallic glass thermoplastic forming unleash the potential to fabricate microscale metallic features with unparalleled precision and durability, i.e. microspine gripping structures for mobility platforms on planetary or in-space robots. Four designs of grippers were fabricated and rigorously tested. Coefficient of friction on four test surfaces were measured and compared to SiC paper and Velcro. The hardness and elasticity of the bulk metallic glasses make them a game-changer in the field, offering a superior alternative to conventional nonmetallic grippers. • Microspine grippers were manufactured via thermoplastic forming of bulk metallic glasses using silicon-on-insulator molds. • The microspines excelled on textured surfaces, where sharp points anchor on to pores or softer regions. • Mechanical behavior of microspines were studied using nanoindentor-based micro-compression and computer simulations. [ABSTRACT FROM AUTHOR]

The paper presents a case study of the data analysis in the CDHS scattering experiment of particle physics performed in 1983. The case study compares the function of computer simulation in the data analysis with recent philosophical work on the role of simulations in high energy physics (HEP) and the theory-ladenness of the data. In the data analysis of CDHS, computer simulations entered an iterative process of probabilistic data correction. The computer simulation was a crucial ingredient of the data analysis that served to increase the accuracy of the measurement. The way in which simulation was used corresponds in a certain sense to the function of "models as mediators" (Morgan and Morrison), by mediating knowledge about measurement errors and the way of correcting them. I argue that this use of simulation did not give rise to a vicious circle of adjusting data to theory and vice versa but only to a weak, or benign, theory-ladenness of the data compatible with scientific realism. In the publication of the CDHS results, the measurement outcomes are called "observed data", indicating a realist attitude of the physicists towards the measured quantities which does not exactly fit in with entity realism or theory realism. [ABSTRACT FROM AUTHOR]

Abstract: A detailed mathematical process integration model of a pulp and paper mill in the Northern Sweden has been developed. The main objective of this work has been set to describe the practical development of the model with particular emphasis on the development of the digester and evaporation plant sub-models. Actual plant measurements have been used to validate the model. By implementing the sub-models into the complete plant model, the influence of different operation parameters on the overall plant performance has been investigated. Furthermore, introductory studies with the main objective to minimize the plant energy cost have been carried out. [Copyright &y& Elsevier]

The future use of eddy resolving simulations (ERS) such as Large Eddy Simulation (LES), Direct Numerical Simulation (DNS) and related approaches in aerospace is explored. The turbulence modeling requirements with respect to aeroengines and aircraft is contrasted. For the latter, higher Reynolds numbers are more prevalent and this especially gives rise to the need for the hybridization of ERS methods with Reynolds Averaged Navier–Stokes (RANS) approaches. Zones where future use of pure ERS methods is now possible and those where hybridizations with RANS will be needed is outlined. The major focus is the aeroengine for which the component scales are much smaller. This gives rise to generally more benign Reynolds numbers. The use of eddy resolving methods in a wide range of zones in an aeroengine is discussed and the potential benefits and also cost drawbacks with such approaches noted. The tension when using such computationally intensive calculations in an area where the coupling of components and even the airframe and engine is becoming increasingly important is explored. Also, the numerical methods and meshing requirements are considered and the implications of ERS methods for future numerical algorithms. It is postulated that such simulations are ready now for niche uses in industry. However, to perform the scale of simulations that industry requires, to meet pressing environmental needs, challenges remain. For example, there is the need to develop optimal numerical methods that both map to the accuracy requirements for ERS and also future computer architectures. [ABSTRACT FROM AUTHOR]

Aramid paper honeycomb cores have been extensively used in lightweight structures. However, compressive properties of the paper, which are important for predicting the mechanical behaviors of honeycomb cores, can hardly be accurately measured due to the weak out-of-plane bending stiffness. Here, we propose an experimental method to characterize the in-plane compressive properties of the paper, in which the paper is processed into a laminate by the adhesive between layers to prevent the out-of-plane buckling. We also conducted a meso-mechanics model to analyze the compressive behavior. The compressive modulus of the hybrid paper obtained from our proposed method is basically identical to the tensile modulus, and the strength is much larger than previous estimations due to effectively avoiding the buckling. Then the compressive properties are used in numerical simulations to study the compressive properties of hybrid paper honeycombs, and the simulation calculated compressive modulus and strength agree well with experimental results, which verifies the accuracy of our method. This meso-mechanics-based characterization method can be applied to other types of paper and paper-like materials as well. • A meso-mechanics-based experimental characterization method for paper is proposed. • The method can characterize the in-plane compressive properties of paper accurately. • The tested paper properties can give a better prediction of honeycomb properties. [ABSTRACT FROM AUTHOR]

Paper (Maniar and Bhattacharyay, 2021) introduces a discrete random-walk (RW) model with a site dependent waiting time and an external force i.e. a site dependent drift. The RW is compared with a Smoluchowski equation in continuous space and time with space dependent diffusivity and space dependent damping. Using numerical simulations in Maniar and Bhattacharyay (2021) it is shown that the equilibrium distribution satisfies locally the Stokes–Einstein relation i.e. there is a constant temperature in the whole system. Here we show that the result can be recovered analytically with a continuous limit in the RW master equation. Moreover, we evidence that the RW model should be carefully defined in order to satisfy locally Stokes–Einstein relation, indeed a different definition of the discrete RW process describes a system that satisfies the Smoluchowski equation with constant damping, where the temperature is not uniform. [ABSTRACT FROM AUTHOR]

Abstract: In this paper, the prospect of integrating a combined paper&pulp mill with fuel production via biomass gasification was investigated. In the study, three different types of gasifiers (circulating fluidised bed, entrained flow and indirect gasification) and three fuel processes (dimethyl ether, methanol and Fischer-Tropsch wax synthesis) were investigated using computer simulations. The paper reports differences from the stand-alone cases and the integrated cases, using the electricity equivalence efficiency as a measure. Only 6 out of the 18 integrated cases studied displayed a positive result from integration and no obvious fuel selection that stand out as the most beneficial one, however the synthesis of dimethyl ether is, in combination with all gasifiers assessed a rather good choice, with an change in efficiency from integration ranging from −1% to 4%. Dimethyl ether is not the best choice if the electrical equivalence is to be maximised however. In this case the combination of circulating fluidised bed gasification and methanol synthesis should be pursued. The production of Fischer-Tropsch wax should according to the chosen measure not be produced; however there is an added value in the production of a non-oxygenated fuel which has not been taken into account in this particular study. All cases leads to a reduction of 0.4–0.9 kg CO2 per kg of dry biomass used in the process for fuel synthesis and the possibility to export bark is a more significant factor in this respect than which type of fuel is synthesised. [Copyright &y& Elsevier]

The program code in the paper “Computer simulation of Talbot phenomenon using the Fresnel integrals approach” ( http://dx.doi.org/10.1016/j.ijleo.2016.01.175 ) is incompatible with MATLAB 7 and MATLAB 8. According to MATLAB documentation mfun function will be removed in a future release, besides str2double function is used. [ABSTRACT FROM AUTHOR]

In order to understand and master the diffusion mechanism and spatial concentration distribution of hydrogen leakage in the engine room, this paper studies the diffusion behavior and concentration distribution of hydrogen under the coupling effect of multiple factors, and further explores the optimal installation location of the sensors. The results indicate that when the ventilation rate increases by 1, 2, and 3 times, the diffusion volume of hydrogen decreases by about 0.4, 0.5, and 0.6 times. The harm of the increase in leakage diameter is greater than the leakage pressure. And the temperature has a greater impact on the hydrogen volume fraction in areas below 4 % and a smaller impact on areas above 4 %. In this environment, the sensors should be installed at or above 5.5 m in the rear of the engine room and above the axis of the hydrogen transport pipeline interface, valves and other places prone to leakage. • Taking a ship engine room as the research object. • The influence of various factors on hydrogen distribution is compared. • The spatial concentration distribution of hydrogen leakage is analyzed. • Explored the installation position of the sensors. [ABSTRACT FROM AUTHOR]

This paper proposes a method to describe the bi-modular behavior of quasi-brittle materials. The approach is based on using multiple loading functions that are associated with the stress state of the material point. The model also includes degradation laws that control the evolution of the internal variables under tension and compression, which allows the representation of the material response with fidelity. The following approach outlines an objective methodology for improving classical models and provides a theoretical framework for developing new constitutive models. This work also presents an updated version of the Mazars damage model, with improved material parametrization through multiple damage laws. Similarly, the modified von Mises model has been extended to include different functions for damage evolution, combining exponential and continuum polynomial laws for tension and compression. A third model was developed to showcase the full potential of the proposed formulation. This model formulates the Lemaitre and Chaboche criterion, typically used for ductile materials, to describe quasi-brittle materials. The model provides a comprehensive characterization of the tension and compression behavior by utilizing various loading functions and multiple damage laws. Numerical simulations of experimental benchmarks are presented to show the performance of the proposal, including a nonlocal approach to avoid strain localization and mesh dependency problems. • A formulation to represent simply the bi-modularity of quasi-brittle materials by isotropic damage models is presented. • The proposal provides versatility to prescribe any damage law, especially with fill constitutive parameters. • The strategy is applied to classical models present in literature providing an enhancement of the model behavior. • The approach can be extended and applied to other models presented in the literature. [ABSTRACT FROM AUTHOR]

In the present comment, the results of recently published by Li Shu and Yonglin Ju "Numerical Study on the Condensation Characteristics of Various Refrigerants Outside a Horizontal Plain Tube at Low Temperatures" in International Journal of Thermal Sciences 2022 are discussed. It is shown that one of the conclusions of the work that "at low saturation temperatures, the periodic-averaged heat transfer coefficient in the numerical simulation is lower than that calculated with Nusselt's equation, especially at large wall subcooling", is not supported by the results of simulation performed by the author of this comment. [ABSTRACT FROM AUTHOR]

Abstract: People often attribute their reluctance to study texts on screen to technology-related factors rooted in hardware or software. However, previous studies have pointed to screen inferiority in the metacognitive regulation of learning. The study examined the effects of time pressure on learning texts on screen relative to paper among undergraduates who report only moderate paper preference. In Experiment 1, test scores on screen were lower than on paper under time pressure, with no difference under free regulation. In Experiment 2 the time condition was manipulated within participants to include time pressure, free regulation, and an interrupted condition where study was unexpectedly stopped after the time allotted under time pressure. No media effects were found under the interrupted study condition, although technology-related barriers should have taken their effect also in this condition. Paper learners who preferred this learning medium improved their scores when the time constraints were known in advance. No such adaptation was found on screen regardless of the medium preference. Beyond that, paper learning was more efficient and self-assessments of knowledge were better calibrated under most conditions. The results reinforce the inferiority of self-regulation of learning on screen and argue against technology-related factors as the main reason for this. [Copyright &y& Elsevier]

Abstract: Effects of suction pressure and permeability on the steam heating characteristics of the wet paper are studied. Experimental results show that suction pressure enhances the energy absorption in the wet paper and effects of suction pressure strongly appear in the high-permeability paper, and also absorbed energy rate is decreased with increasing in heating time. From the numerical simulation results it is found that increase in moisture content and decrease of pressure gradient reduce the absorbed energy rate. Dimensionless numbers are derived from the basic equations to summarize the experimental and numerical simulation results. [Copyright &y& Elsevier]

Today, there is growing interest in computer surgical simulation to enhance surgeons’ training. This paper presents a simulation system based on novel algorithms for animating instruments interacting with deformable tissue in real-time. The focus is on computing the deformation of a tissue subject to external forces, and detecting collisions among deformable and rigid objects. To achieve real-time performance, the algorithms take advantage of several characteristics of surgical training: (1) visual realism is more important than accurate, patient-specific simulation; (2) most tissue deformations are local; (3) human-body tissues are well damped; and (4) surgical instruments have relatively slow motions. Each key algorithm is described in detail and quantitative performance-evaluation results are given. The specific application considered in this paper is microsurgery, in which the user repairs a virtual severed blood vessel using forceps and a suture (micro-anastomosis). Microsurgery makes it possible to demonstrate several facets of the simulation algorithms, including the deformations of the blood vessel and the suture, and the collisions and interactions between the vessel, the forceps, and the suture. Validation of the overall microsurgery system is based on subjective analysis of the simulation’s visual realism by different users. [Copyright &y& Elsevier]

The parameter L 0 with a unit length (=1.0 m) was omitted in our paper, and the unit of loading speed s 1 and the expression of parameter c 7 were not shown, which result in that the dimensions of shear strain and shear strain rate shown in Eq.(16) were misinterpreted. In this response paper, we added the L 0 in the expressions of parameters c 6 and q , and explained the unit of s 1 , as well as gave the expression for the c 7. The addition of L 0 do not change the simulation results and conclusions of our paper. [ABSTRACT FROM AUTHOR]

This paper presents a reply to the discussion of the paper “Numerical simulation of moisture transport in concrete based on a pore size distribution model” by Q. Zeng and S.L. Xu. [ABSTRACT FROM AUTHOR]

Volatile Organic Compounds (VOCs) are widely concerned owing to their serious harm to the ecological environment and human health. In this paper, the adsorption effect of VOCs on a new type of swirling fluidized bed was studied from two aspects of numerical simulation and experimental research, which expanded the application of the device in the field of VOC removal. It was found that the adsorption efficiency of activated carbon in the cyclone fluidized bed was inversely proportional to the inlet concentration and the height of the spinning core column, and was proportional to the mass of the adsorbent and the diameter of the spinning core column. When SAC-3 activated carbon and cyclone fluidized bed S 16–22 were selected, the highest adsorption efficiency was up to 100%, and the damage rate of activated carbon was not more than 3%. The simulation results showed that the maximum axial velocity and the maximum tangential velocity existed in the annular space. The axial velocity and tangential velocity on the cross-section first increased and then decreased with the increase of the radius. The axial velocity was proportional to the flow rate, the diameter, and height of the spinning core. The tangential velocity first increased and then decreased with the increase of the flow rate, diameter, and height of the spinning core. The overall pressure increased with the increase of the flow rate, the pressure increased with the increase of the radius in the cross-section, and the pressure decreased rapidly with the increase of the height in the axial direction. In this paper, a new type of cyclone fluidized bed is used to replace the existing fixed bed and carry bed system, and the optimal activated carbon, the best working conditions, and the best rotary fluidized bed structure are screened by the cyclone fluidized bed experiment. [Display omitted] • A new cyclone fluidized bed was developed for the adsorption treatment of VOC. • CFD method was used to study the internal flow field characteristics. • The best experimental conditions are explored. • The cyclone fluidized bed can effectively treat VOC with sustainable operation. [ABSTRACT FROM AUTHOR]

The Shuiyindong gold mine in Guizhou is used as a case study in this paper to study patterns of dust pollution occurring with traditional electric-rake operation. In particular, the study uses the northern quarry of the twenty-third line in the first middle section of the second mining area and establishes a three-dimensional simulation model of equal size. It uses Computational Fluid Dynamics (CFD) to simulate and analyse the airflow traces and distribution of dust concentration in the relevant roadway during each stage of the electric-rake operation. The simulation results show that the airflow in the working roadway has a spiral movement and produces reverse dirty-wind circulation towards the end. Dust flows out of the working roadway from the 8th second of operation, and dust concentration reaches a peak in the working roadway at the 12th second of operation at an average dust concentration of 37.5 mg/m³. The dust concentration drops rapidly from the 120th second and reaches the maximum dust concentration permitted for operation at the 180th second of operation. The validity of the simulation is tested by comparing the actual measured data at the site with the simulation results. Finally, the simulation results are analysed using violent Python, and the solution is used to divide the roadway into areas according to the human breathing range. The paper analyses the distribution of dust concentration at an average human breathing height, providing an established theoretical basis for dust-control work in mines. [Display omitted] [ABSTRACT FROM AUTHOR]

Air combat scenarios present unique problems where the solution is not obvious. An advanced networked simulation environment can be used to train high-level cognitive air combat skills such as problem solving. A problem in the development of principled and construct oriented assessment is related to determining the level of specificity of the assessment. We present a detailed discussion of the definition of critical competencies associated with combat mission problem solving performance, and we describe our approach to develop and implement an embedded performance assessment system that maps outcomes to these competencies. Finally, we discuss the implications for our approach for comprehensive assessment and discuss our goals for an evaluation of the competency-based approach to assessment. [Copyright &y& Elsevier]

• An optimal nutation reduction method based on a flexible contactor is proposed. • A highly efficient data-driven model is established to describe the contact process. • The nutation of a tumbling satellite can be reduced efficiently in the early stage of the de-tumbling tasks. Stabilizing tumbling satellites is a crucial step in ensuring safe on-orbit capture. A new de-tumbling method has been proposed that uses a flexible device, such as a brush or rod, to make contact with the target object and avoid potential collisions. However, this method faces two challenges: (i) The complex rotary motion makes it very difficult to determine the contact position on the target satellite, which is crucial to reduce nutation during de-tumbling. (ii) The conventional finite-element-based dynamic model of the flexible contactor is high-dimensional, leading to unacceptable computing time for on-orbit simulation. To address these problems, this paper proposes an optimal method to efficiently reduce the nutation by predicting the initial contact position for each contact process. Additionally, a fast computation model of the de-tumbling system is established based on a data-driven approach to support real-time prediction. Finally, numerical simulations are conducted to demonstrate the effectiveness and high efficiency of the proposed method. [ABSTRACT FROM AUTHOR]

• A method of uncertainty analysis based on the MP-II model was proposed to examine a case of adhesive assembly. • Uncertainty transfer was constructed by a combination of finite-element simulation and a B-spline surrogate model. • The effect of the uncertainties of three types of bonding defects on the center-of-mass drift was understood. • The reliability index was improved and the parameter intervals of the bonding defects were optimized. Multi-source and strong uncertainties of the adhesive assembly process for high-precision inertial devices are critical issues that result in the current low assembly accuracy and poor assembly consistency. This paper addresses the resulting uncertainty in the center-of-mass drift of the float components of a high-precision inertial device. An interval-based non-probabilistic convex model is used to characterize the uncertainty of the bonding defect parameters of the adhesive assembly process, and the uncertainty transferring from those parameters to the center-of-mass drift is constructed by using a surrogate model and numerical simulations. A reliability analysis is carried out to understand the effect of the uncertainties of three types of bonding defects on the center-of-mass drift, and the sensitivities of the center-of-mass drift to the bonding defects are also found. The results show that the reliability index of the center-of-mass drift obtained under the initial parameter intervals is 0.689, indicating the center-of-mass drift at the risk of being out of the accuracy requirement. By adjusting the parameter intervals of the bonding defects to stabilize the center-of-mass of the assembled components, the reliability index is then improved to greater than 1. [ABSTRACT FROM AUTHOR]

This paper presents a numerical study of counterflow methane/n-heptane dual fuel flames, investigating the influence of pressure on flame structure and NO generation characteristics. The results demonstrate that, as pressure increases, the peak temperature and heat release rate of the flame increase, while the NO emission index decreases. The prompt NO emission index experiences a monotonic reduction as pressure increases, while the thermal NO emission index initially increases and then decreases. NO emission index via reburn route displays non-monotonicity with increasing pressure. Elevated pressure induces a decline in the mole fraction of radicals (CH, CH 2 and HCCO) crucial for prompt NO formation, consequently suppressing the formation of prompt NO. The principal reaction responsible for the consumption of reburn NO at lower pressures is HCCO+NO CO+HCNO, whereas the primary reaction for generating reburn NO is H+HNO H 2 +NO. However, at higher pressures, the reaction H+HNO H 2 +NO takes precedence as the dominant reaction consuming NO. • NO emission index decreases with increasing pressure. • Sensitivity analysis of NO generation under different pressures is conducted. • The formation routes of NO under different pressures are identified and analyzed. • The primary NO formation route changes from prompt to thermal as pressure rises. [ABSTRACT FROM AUTHOR]

This paper mainly studies the high-order stable numerical solutions of the time-space fractional diffusion equation. The Fourier spectral method is used for discretization in space and the Spectral Deferred Correction (SDC) method is used for numerical solutions in time. Therefore, a high-precision numerical discretization scheme for solving the fractional diffusion equation is obtained, and the convergence and stability of the scheme are proved. Finally, several numerical examples are given to illustrate the effectiveness and feasibility of the numerical scheme. [ABSTRACT FROM AUTHOR]

Plasma gasification technology is a harmless and resourceful solid waste treatment method. As a hazardous waste, studying the plasma gasification treatment of oil-based drilling cuttings has practical significance. Therefore, this paper uses Aspen Plus to establish a plasma gasification model. Based on model validation, the effects of input power, oxygen equivalence ratio, and carrier gas type on the plasma gasification process of oil-based drilling cuttings were discussed. In addition, by designing a quadratic regression orthogonal experiment, a nonlinear quadratic regression equation was established between the three factors of gasification pressure, input power, and equivalence ratio, as well as different gasification indicators, namely gas yield, lower heating value, and gasification efficiency. By solving the equation, it was found that when the gasification power is 70 kW, the gasification pressure is 10 atm, and the equivalence ratio is 0.1, the gas yield reaches its maximum of 0.74 kg/m3; When the gasification power is 15 kW, the gasification pressure is 10 atm, and the equivalence ratio is 0.1, the lower heating value of gas production reaches its maximum of 9.68 MJ/m3; When the gasification power is 15 kW, the gasification pressure is 1 atm, and the equivalence ratio is 0.1, the gasification efficiency reaches its maximum of 37.6%. At the same time, it was found that the influence of gasification pressure, input power, and equivalence ratio on gasification indicators was ranked in descending order as equivalence ratio, input power, and gasification pressure. The above research provides certain reference values for the practical operation of plasma gasification of oil-based drilling cuttings. • Analyzed the effects of different factors on plasma gasification of OBDC. • Optimum parameters of plasma gasification of OBDC are studied. • Ranked the degree of influence of different factors on plasma gasification of OBDC. • Analyzed the efficiency of plasma gasification of OBDC. [ABSTRACT FROM AUTHOR]

Rotational moulding is a versatile polymer shaping process used to create enclosed parts from powdered precursors using heat and multi-axis rotation. Controlling the heating process and mould motion is critical to producing high-quality parts, and failures due to incorrect mould coverage or variable wall thickness are common. To date, limited simulation tools exist to predict the motion of the powder within the mould, and operators rely on unreliable prior experience to avoid defects. This paper presents an SPH simulation framework to predict particle flow patterns and powder contact time within a rotating mould. The powder-to-wall contact time was derived from the transient rigid body force (RBF) of different sensors on the mould. The method was compared with the results of DEM simulation and validated by the particle flow pattern of two experimental results. Results showed that the SPH method was capable of simulating particle flow macroscopic properties. The great computing efficiency of SPH compared to DEM simulation was also demonstrated. • Couple the SPH framework with a soil material model to simulate the polymer flow motion during rotational moulding process. • Modelling framework validated by two experimental benchmarks. • Present a significant benefit compared to the DEM method when simulating particle flow with millions of particles. [ABSTRACT FROM AUTHOR]