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Our students belong to a highly digitised generation with easy and rapid access to information. They are dependent on technology and tend to become bored quickly. There is an ongoing debate regarding the need to reconsider our teaching methods in order to capture the attention of our students. This study surveyed both students and teachers on the subject of online teaching and its impact on university education. Additionally, it explored issues related to integrating interactive applications in education. These applications are considered essential tools in combating student boredom and disinterest. They also enable teachers to receive valuable feedback, which was highlighted as critically important by educators in the survey. In this context, we conducted a study within a chemical engineering program at a Spanish university. We examined the use of four different interactive applications (Kahoot!, Wooclap, Classflow, Moodle) and compared the results with those from previous years when only one of these applications was employed. This study aimed to determine how using multiple applications led to increased student participation, driven by avoiding monotony, resulting in improved academic performance. • Students and teachers prefer a face-to-face model due to more significant interaction. • The use of interactive applications helps to maintain attention and the feedback teacher/student. • The favourite application for students and teachers is Kahoot!. • The employ of several tools increases the student's participation and improves their academic marks. [ABSTRACT FROM AUTHOR]

Practice in experimental laboratories is a fundamental activity in the Degrees in Science and Engineering. FLUID-LABVIR platform is an attempt to innovate in the experience of students who must carry out laboratory practices, particularly in engineering and fluid mechanics subjects, by providing them with a tool (guide prepared as a website) adapted to the context of current media in a multi-platform web format (PC, mobile, tablet). This guide not only includes the theoretical foundations and the measurements which must be taken during the practice, but also includes images, animations, and explanatory videos of the handling of the practice made by teachers to support the theoretical content. It is also an additional tool to practice the handling of the experimental installation through an immersive simulator that reproduces the operation of the practice as faithfully as possible, including calibration errors of measuring equipment during the practice, saturation of indicator elements, etc. On this website, students have the possibility of downloading or accessing the practice simulator via the MyApps platform, so that they can work virtually with the demonstrative equipment, following the steps and taking the measurements that they would take in person in the laboratory. This simulator is accompanied by a short video tutorial showing how to use the simulator and how it would be operated to reproduce the handling and taking of measurements in the experimental practice. The virtual laboratory activity was implemented during the 2020/21 academic year, through three practices/simulators: Head Loss in Pipes (FM-HLP), Flow in Open Channel (FM-OC), and Wind Tunnel (FM-WT). The students considered the activity as a good complement to the practical learning before using it in the laboratory, indicating that the script seemed more attractive to them than the previous methodology based on written manuals of each practice in the laboratory. The theory and practice are also presented in more depth on the website. The students highlighted that, although it is always preferable to carry out the experimental practice in person, the immersive simulator seemed to them to be a good substitute, and the website was accessible and easy to use. The simulator reproduced the handling (stages, devices, etc.) of the experimental installation in a very acceptable way, and in some cases, they used the simulator to obtain additional data to prepare the final report of the practices. As a result of this work and this experience, the virtual laboratory activity will be offered as a complement to the traditional syllabus in the labs for subsequent academic years. • FLUID-LABVIR, an online platform as innovative way to teach experimental laboratories. • Webpage is based on audio-visual material and an immersive simulator of installation. • FLUID-LABVIR is open to all the students and educator community. • The students consider FLUID-LABVIR a good complement to the practical learning. [ABSTRACT FROM AUTHOR]

• Novel multiregional DOM with anisotropic scattering developed for OpenFOAM. • Successful validation vs analytical solution and verification vs standard DOM. • Quadrature rotation reduces significantly the directional error in parallel beams. • Power cosine or cone shaped adjusted quadrature for improved simulation of LED. This work describes adaptive quadrature, a new feature designed to improve the Discrete Ordinate Method (DOM) in parallel and cone-shaped radiation sources. OpenFOAM was chosen as the simulation framework to implement the new feature. It already included a Discrete Ordinate Method (fvDOM), but it focuses on thermal radiation and is limited to isotropic emission, diffuse phenomena, and non-scattering media. The model was completed to cover volumetric and superficial absorption, isotropic and anisotropic scattering (with user-defined phase functions), diffuse and specular reflection, diffuse and parallel transmission, and three types of superficial emission sources, i.e., isotropic, cone-shaped, and parallel. Additionally, the model is prepared to work in grey mode or with wavelength bands. Multiple regions with different optical properties are also allowed. Most of the model has been validated by individual simulations of every feature in simple geometries that permit an analytical solution, with errors between 0% and 6.08%. These simulations were also verified in a comparison with an established version of the standard DOM, with differences between model implementations below 2.5%. Some advantages of the developed adaptive quadrature are also analysed using simulation results for different radiative sources and angular discretization. The main conclusion is that adaptive quadrature better defines view angle and light direction of emission sources compared to the established DOM, improving significantly the accuracy of the simulation of non-isotropic sources. [ABSTRACT FROM AUTHOR]

• Large nanotubular TiO 2 photocatalytic membranes prepared by anodization. • Galvanostatic anodization improves the process over potentiostatic conditions. • Confirmed activity for photocatalytic methanol oxidation and E.coli inactivation. • Hybrid process proved synergism between filtration and photocatalysis. • Nanotubular TiO 2 do not significantly improve activity of nanoparticulate TiO 2. Hybrid photocatalysis/membrane processes constitute promising alternatives for water and wastewater treatment because they combine the efficiencies of filtration membranes technology and the oxidative effect of the photocatalytic process, increasing the lifetime of the membranes. The main challenge of these systems is the incorporation of the titanium dioxide (TiO 2) catalyst without altering the filtration properties of the membrane and the photocatalytic activity of the catalyst. One way to achieve this goal is generating the TiO 2 layer by direct anodization of titanium supports under controlled conditions to form titanium dioxide nanotubes (TiO 2 -NTs). This work reports the development of novel photocatalytic titanium membranes based on the formation of TiO 2 -NT arrays by anodization under both potentiostatic and galvanostatic conditions, and the scaling-up of the most promising systems to operational membrane photoreactors. The results demonstrated that the galvanostatic method displays more controlled tuneability to obtain NTs formation than the potentiostatic method on porous surfaces. However, despite the formation of TiO 2 -NTs structures, the observed photocatalytic activity is lower than that exhibited by TiO 2 nanoparticles deposited directly on the membrane, although in this case the transmembrane pressure is significantly higher, and therefore the operational pumping costs are greater. Synergistic effects of photocatalysis and microfiltration are clearly demonstrated in the application of the hybrid system to the removal of bacteria for water disinfection processes, showing a significant improvement in the inactivation of E. coli bacteria in water with respect to the bare membrane. [ABSTRACT FROM AUTHOR]

Graphical abstract Highlights • New mechanistic kinetic model proposed for NO x photocatalytic oxidation. • Intrinsic kinetic parameters for NO x removal determined in the ISO 22197-1 reactor. • Radiation homogeneity validated by numerical simulation. • Plug flow hypothesis confirmed by computational fluid dynamics simulation. • Successful model validation with prediction errors in the conversion below 13%. Abstract An air purification reactor working under the standard ISO 22197-1 is studied and used for the determination of the intrinsic kinetic parameters of the NOx photocatalytic removal. A new mechanistic kinetic model considering explicitly the radiation step is proposed. The derived reaction rate expressions for NO and NO 2 include the dependence on the concentration of NO, NO 2 and the local superficial rate of photon absorption. The air purification reactor was modelled using a numerical simulation methodology to validate homogeneity of the light distribution reaching the catalyst surface and go deep in the knowledge of fluid dynamic behaviour. Based on these results, general guidelines of the reactor behaviour working under the ISO 22197-1 standard can be stablished, being the first time that this reactor is modelled with a global predictive approach. Radiation intensity over the catalyst surface was confirmed to reach the specified value of 10 ± 0.5 W m−2. Plug flow can be applied in the studied reactor with an axial dispersion module lower than 0.001. However, the diffusion of chemical species in the reactor was also studied, as well as the impact of mass transfer phenomena on the accuracy of the calculated kinetic parameters. A comprehensive simulation model of the ISO reactor, including fluid dynamics, radiation, photochemical reaction and mass transfer was developed. The simulation results confirm that the kinetic parameters obtained without considering mass transfer limitation fail to reproduce the experimental data, whereas a global error lower than a 17% was achieved including the diffusion of the species in the reactor. The proposed methodology, experimentally validated, could be successfully applied to the prediction of the performance of different type of photocatalytic reactors or even open systems for NOx pollutants. [ABSTRACT FROM AUTHOR]

This work presents the development of a novel methodology for the simulation of photochemical processes for water disinfection using computational fluid dynamics (CFD). A new approach was implemented to calculate and visualise the disinfection performance as the microorganisms move along the photoreactor. Hydrodynamics and microorganism's statistical trajectories were computed using the discrete phase model, which also provides the distribution of microbial residence times. The distribution of radiation in the reactor was calculated using the discrete ordinate method. The local values of incident radiation were integrated over each statistical trajectory path to get the accumulated dose received for each microbial particle. The coupling in situ of the cumulative radiation dose with the inactivation kinetics allows monitoring of the disinfection process concurrently with the particle tracking. This methodology introduces significant advantages over the traditional estimation of the microorganism inactivation sequentially after calculating the dose histograms estimated from the statistical trajectories. The developed tool enables evaluating the photoreactor efficiency in each reactor position, a useful capability for optimising and scaling up complex geometries. It also allows the easy, intuitive visualisation of microbial inactivation trajectories, improving the understanding of the influence of the reactor features on the disinfection process. Application of this computational approach to two different photoreactor geometries using a virus as a representative target microbe is presented. [Display omitted] • Multiphysics CFD simulation of microbial inactivation in photochemical reactors. • Residence time distribution calculated with the discrete phase model. • Cumulative radiation dose computed along the microbial trajectory. • In situ coupling of radiation calculation with the inactivation kinetics. • Application to virus inactivation in two different photoreactors. [ABSTRACT FROM AUTHOR]

This work describes the procedure for the simulation of the operation of a photocatalytic reactor by using a multiphysics computational fluid dynamics (CFD) model based on the determination of the intrinsic kinetics parameters in an optically differential photoreactor. The model includes the rigorous description of the hydrodynamics, radiation transfer, mass transport and chemical reaction rate based on a mechanistic kinetic model. Possible existence of dead and recirculation zones has been identified from the flow field, showing a non-uniform flow through the reactor domain. The theoretical laminar profile is not reached due to the short length of the annular core and the departure from the ideal models has been quantified. The predicted velocity field has been experimentally validated with good agreement by injecting a tracer. The radiation field was simulated for slurry TiO 2 suspensions with concentrations between 0.005 and 5 g·L −1 , showing an optimum catalyst loading around 0.1–0.2 g·L −1 . Above this value, the increase in the absorption of radiation is negligible, whereas a more non-uniform radiation profile develops, keeping the most external regions of the reactor in the dark. The results of photocatalytic activity, using methanol oxidation as test reaction, showed good agreement between model predictions and experimental data, with errors between 2% and 10% depending on the catalyst concentration. The successful validation confirms not only the scientific background of the model, but also supports its applicability for engineering purposes in the design and optimization of large scale photocatalytic reactor to overcome some of limitations hindering the industrial development of this technology. [ABSTRACT FROM AUTHOR]

A novel method for preparing hybrid polymer-titania nanotube (TNT) arrays with promising optical, catalytic and filtration applications is reported. The procedure is based on a one-step rapid galvanostatic anodization followed by the transfer of the TNT arrays to a polymer support by applying heat and pressure. The fraction of open-ended tubes can be controlled by changing the intensity of the current at the end of the anodization step. For example, completely open-ended or close-ended TNT arrays can be obtained by applying high or low current intensity, respectively at the end of the anodization process. The reported procedure allows the one-step simple and rapid preparation of flexible hybrid polymer-TNT materials which have great potential for photonic flow-through membranes. [ABSTRACT FROM AUTHOR]

• Heterojunction BiVO 4 -Bi 2 O 3 proved to be viable for degradation of atrazine in water. • The heterojunction formation improved photodegradation of atrazine. • Atrazine was degraded to a less toxic compound, cyanuric acid. • Holes, hydroxyl, and superoxide radicals were responsible for the degradation. Conventional methods have been reported to fail to completely remove contaminants of emerging concern (CECs) during wastewater treatment. Thus, new methods are required to improve wastewater treatment to completely remove the CECs from water. In this paper, we present the degradation of atrazine in aqueous solution using heterojunctions of BiVO 4 and Bi 2 O 3 that were synthesized from different morphologies of BiVO 4 (truncated octahedron, plate-like, and platelet-like). The nanoparticles (NPs) were characterized using a scanning electron microscope, X-ray diffraction, UV–vis diffuse reflectance spectroscopy, photoluminescence spectroscopy, electrochemical impedance spectroscopy, and X-ray photoelectron spectroscopy. It was observed that the heterojunctions were successfully synthesized and the observed morphologies for the BiVO 4 were truncated octahedron, plate-like and platelet-like. The most effective heterojunction in the removal of atrazine was 0.5NaCl-BiVO 4 -Bi 2 O 3. The 0.15HPEI-0.5NaCl-BiVO 4 -Bi 2 O 3 had a reduced reaction rate compared to 0.5NaCl-BiVO 4 -Bi 2 O 3 , even though characterization showed that it was expected to be the most effective of all the NPs. The degradation of atrazine proceeded through dehalogenation, followed by the dealkylation and further deamination into cyanuric acid, a stable and less toxic compound. Data from LCMS/MS showed the formation of hydroxyatrazine, desethylhydroxyatrazine, and ammeline as intermediates. The degradation of several concentrations of atrazine revealed that the heterojunction efficiently removed >90 % of atrazine. [ABSTRACT FROM AUTHOR]