Reactor Applications Research Articles

Enhancing the Photocatalytic Activity of Immobilized TiO2 Using Laser-Micropatterned Surfaces

In the past, the application of TiO2 slurry reactors has faced difficulties concerning the recovery and reusability of the catalyst. In response to these challenges, immobilized photocatalyst systems have been investigated, wherein the catalyst is fixed onto a solid support, frequently with reduced photocatalytic performance. In the present study, thin TiO2 films were developed in the anatase phase by the sol-gel process and spin-cast on laser-microstructured silicon substrates, to form photocatalytic surfaces of increased activity. The TiO2 films were thoroughly characterized using SEM-EDX, XRD, UV–Vis spectroscopy, and Raman spectroscopy. The photocatalytic activity of these surfaces was evaluated by the degradation of atrazine in aqueous solution under UV irradiation. Their photocatalytic activity was found to be significantly enhanced (mean kobs 24.1 × 10−3 min−1) when they are deposited on laser-microstructured silicon compared with flat silicon (mean kobs 4.9 × 10−3 min−1), approaching the photocatalytic activity of sol-gel TiO2 fortified with Degussa P25, used as a reference material (mean kobs 32.7 × 10−3 min−1). During the photocatalytic process, several transformation products (TPs) of atrazine, namely 2-chloro-4-(isopropylamino)-6-amino-s-triazine (CIAT), 2-chloro-4-amino-6-(ethylamino)-s-triazine (CAET), and 2-chloro-4.6-diamino-s-triazine (CAAT), were identified with LC–MS/MS. The stability of the photocatalytic surfaces was also investigated and remained unchanged through multiple cycles of usage. The surfaces were further tested with two other pollutants, i.e., 2,4,6-trichlorophenol and bisphenol-a, showing similar photocatalytic activity as with atrazine.

Modeling and analysis of the triple diffusion unsteady flow of couple stress nanofluid with variable viscosity and distinct thermal sources

Thanks to their optimal thermal characteristics, nanomaterials stand out for their varied applications in heat transfer systems, energy storage, industrial processes, and biomedical research. Recently, scientists explored various dynamic properties in nanofluid flow to develop an even better thermal model. In this context, the phenomenon of triple diffusion in nanofluids constitutes an active area of research, offering promising applications in nanotechnology, metallurgical processes, chemical reactors, and thermo-diffusion processes. This paper analyzes the triple diffusion flow of a torque-constrained nanofluid, induced by a periodically oscillating porous surface, taking into account the importance of variations in thermal consequences. The viscosity of the torque-constrained nanofluid is assumed to be temperature-dependent. The analysis takes into account the variable role of thermal conductivity, mass diffusivity, and solute volume fraction. The modeling of the problem is expressed by coupled nonlinear partial differential equations. The semi-analytic technique, known as the homotopic analysis scheme, is used for resolution. The solution is validated and confirms the convergence region. The physical aspects of the parameters are examined with regard to the parameters involved. The simulated observations reveal that with the Dufour–Lewis factor and varying mass diffusivity, an increase in solute concentration is seen. The concentration of nanoparticles decreases with the nano-Lewis number.

Recent Advances in Using Microwaves to Prepare Chemicals at the Industrial Level

Abstract: Microwave-assisted synthesis has faced challenges in implementing its use at the in-dustrial level in recent decades, including scaling up the processes. While microwave-assisted synthesis is established on a laboratory scale, there are some drawbacks associated with it, in-cluding the equipment and operational costs of the specialized microwave reactors, safety con-cerns due to high temperatures and pressures, reaction selectivity, capacity to control the rapid heating and cooling rates associated with the kinetics of some reactions, and optimization of re-producibility in the results. This manuscript discusses the relevant and recent news in the last ten years about the application of industrial reactors for producing chemicals at the industrial level.

Development of potassium doped tungsten plate for fusion reactor applications

Since fusion reactors including DEMO and beyond are expected to be operated for a longer period of time than ITER, plasma-facing materials (PFM) will suffer by longer term heat load and non-negligible neutron irradiation damage. Therefore, for tungsten (W) materials as PFM, improvement of low temperature brittleness and suppression of recrystallization embrittlement and neutron irradiation embrittlement are required. To address these issues, various modified W materials have been developed by applying alloying with solid solution elements and second-phase dispersion techniques such as solid particles and bubbles. As a result, potassium-doped W (K-doped W), in which K bubbles are dispersed, was found to be effective for all of the above issues. However, the materials used in these evaluations were relatively small and not large enough to fabricate, for example, ITER divertor monoblocks (12 mm thick). In the present study, K-doped W plate with a sufficient thickness (more than 12 mm) for application to fusion reactor components like divertor monoblocks were developed and the fundamental properties were evaluated.

The Application of an Upflow Anaerobic Sludge Blanket Reactor in the Treatment of Brewery and Dairy Wastewater: A Critical Review

Brewery (BW) and dairy (DW) wastewater are two types of agro-industrial wastewater that are generated in large amounts and, therefore, should be treated effectively and in an environmentally beneficial manner. Both these wastewater types are characterized by a high COD, BOD5, and nutrient content, and conventional wastewater treatment methods such as an activated sludge process may prove to be inefficient due to the possibility of foaming, large biomass production, low activity at low temperatures, and risk of overloading the reactor with a load of organic pollutants. In the context of the described difficulties, anaerobic processes seem to be the best alternative. An interesting research area is the co-digestion of these wastewaters. However, this research direction, so far, has not been frequently reported. Given the gap in the current knowledge, this literature review aims to assess the possibility of BW and DW digestion in anaerobic reactors and provide up-to-date data on the post-treatment methods of effluent generated after the anaerobic digestion process. Despite numerous advantages, anaerobic treatment often requires post-effluent treatment to complete the treatment cycle.

On the Employment of a Chloride or Floride Salt Fuel System in Advanced Molten Salt Reactors, Part 2; Core Inventory, Fuel Burnup, and Salt Clean-Up System

Breed and Burn (B&B) fuel cycle in molten salt reactors (MSRs) qualifies this reactor type as one of the best candidates to be developed for the Gen-IV R&D program. This feature can be approached by employing a closed fuel cycle and application of a molten salt reactor as a spent nuclear fuel burner; the features promise sustainable and clean energy in the future. In this study, a complete package has been developed to calculate core inventory, fuel burnup, and salt clean-up systems of molten salt reactors during their lifetime. To achieve this, the iMAGINE-3BIC package (“iMAGINE 3D-Reg Burnup & Inventory Calculator package”) has been developed in MATLAB R2023a by employing a CINDER90 module of MCNPX 2.7 for burnup-calculation and multi-linear regression method (MLR). The package can estimate the core inventory (concentration of 25 actinides and 245 non-actinides elements) and the burnup of the reactor core during MSR lifetime (up to 100 years) while optimizing the computational resources (time, CPU and RAM), and it can even be hassle-freely executed on standalone PCs in an appropriate time due to its generous database. In addition, the salt clean-up module of the iMAGINE-3BIC package can be employed to evaluate the effects of the salt clean-up system on the above parameters over the MSRs’ lifetime. Finally, the iMAGINE-3BIC package has been applied to an iMAGINE reactor core design (University of Liverpool, UK—chloride-based salt fuel system) and an EVOL reactor core design (CNRS, Grenoble, France, fluoride-based salt fuel system) to evaluate and compare the performance of chloride/fluoride-based salt fuel MSRs from the point of burnup, core inventory, and salt clean-up systems. The results confirm that while a chloride-based salt fuel system has some advantages in less dependency on the salt clean-up system and fewer poisoning elements inventory, the fluoride-based system can achieve higher burnup during the reactor lifetime. The outcome of this study, along with the first part of this article, provides evidence to support the neutronic decision matrix as well as the pros and cons of employing chloride- or fluoride-based fuel systems in MSR cores.

Potential of combined reactor and static composting applications for the removal of heavy metals and antibiotic resistance genes from chicken manure

Chicken manure (CM) can pose a serious threat to environmental and human health, and need to be managed properly. The compost can effectively treat CM. However, there is limited research on the heavy metals and antibiotic resistance genes (ARGs) during compost CM. In this study, the combined application of reactor and static composting (RSC) was used to produce organic fertilizer of CM (OCM), and heavy metals, ARGs and bacterial community structure was investigated. The results show that RSC could be used to produce OCM, and OCM meet the National organic fertilizer standard (NY/T525-2021). Compared to the initial CM, DTPA-Cu, DTPA-Zn, DTPA-Pb, DTPA-Cr, DTPA-Ni and DTPA-As in OCM decreased by 40.83%, 23.73%, 34.27%, 38.62%, 16.26%, and 43.35%, respectively. RSC decreased the relative abundance of ARGs in CM by 84.06%, while the relative abundance of sul1 and ermC increased. In addition, the relative abundance and diversity of ARGs were mainly influenced by the bacterial community, with Actinobacteria, Firmicutes, and Proteobacteria becoming the dominant phyla during composting, and probably being the main carriers and dispersers of most of the ARGs. Network analyses confirmed that Gracilibacillus, Lactobacillus, Nocardiopsis, Mesorhizobium and Salinicoccus were the main potential hosts of ARGs, with the main potential hosts of sul1 and ermC being Mesorhizobium and Salinicoccus. The passivation and physicochemical properties of heavy metals contribute to the removal of ARGs, with sul1 and ermC being affected by the toal heavy metals. Application of RSC allows CM to produce mature, safe organic fertilizer after 32 d and reduces the risk of rebound from ARGs, but the issues of sul1 and ermC gene removal cannot be ignored.

A nano-Al2O3 modified polypropylene hollow fiber membrane with enhanced biofilm formation in membrane aerated biofilm reactor application

Membrane Aerated Biofilm Reactor (MABR) stands out as an innovative technology for wastewater treatment. However, biofilm formation poses a significant challenge in its implementation. Surface modification emerges as a viable strategy to enhance biofilm development. In this study, biofilm formation was effectively promoted by coating polydopamine (PDA) and loading aluminum oxide nanoparticles (Al2O3 NPs) onto a polypropylene (PP) hollow fiber membrane, aiming to improve wettability and potential. Results from the bacterial attachment assay demonstrated a significantly higher bacterial attachment rate on the membrane loaded with Al2O3 NPs compared to PDA/PP and PP membranes. A comprehensive investigation into the MABR process was conducted, assessing both short-term and long-term (72 days) performance. In the short-term process, the Al2O3 NPs-PDA modified membrane exhibited superior removal efficiency for chemical oxygen demand (COD), ammonium nitrogen (NH4+-N), and total nitrogen (TN) compared to other membranes. Transitioning to the long-term process, the start-up period for the Al2O3 NPs(10)-PDA/PP membrane was notably shortened to 27 days, surpassing the start-up times of PP and PDA/PP membranes by 13 and 5 days, respectively. Throughout the long-term operation, when the influent COD, NH4+-N, and TN concentrations increased, the Al2O3 NPs-PDA/PP membrane consistently maintained removal efficiency above 95%, 98%, and 85% for COD, NH4+-N, and TN, respectively, demonstrating excellent resistance to shock loading.

Achieving high strength and pseudo-ductility in Bf/Cu composite enabled by 3D-Gr@B4C interface-modified layer

Improving wettability, interfacial mechanical and thermal compatibility between reinforced boron fiber and Cu are strongly desirable for developing continuous boron fiber reinforced Cu matrix (Bf/Cu) composite, which shows great potential for application in nuclear fusion reactor as a promising high-strength heat-sink material. Herein, a three-dimensional graphene network hybrid B4C (3D-Gr@B4C) coating was fabricated on B fiber by single filament chemical vapor deposition as the interface-modified layer of Bf/Cu composite. It is revealed that the 3D-Gr in 3D-Gr@B4C interface-modified layer can not only supply diffusion channel to Cu for enhancing interfacial thickness and strength, but also serve as high-thermal-conductivity network to increase TC of Bf/Cu composite from 322.3 W/m·K to 343.9 W/m·K. Meanwhile, modulus of 3D-Gr@B4C interface-modified layer lying between Cu and B can also improve the interfacial mechanical compatibility of composite. Accordingly, interface modification on B fiber using 3D-Gr@B4C layer enables tensile strength up to 1016 MPa at RT and 620 MPa at 300 °C, which are ∼1.3 and ∼1.5 times higher than the corresponding values of Bf/Cu composite, respectively. Furthermore, introducing 3D-Gr@B4C layer inhibits abrupt failure of Bf/Cu composite at small tensile strain and opens up fiber pull-outs and shearing of Cu matrix at large tensile strain, producing pseudo-ductile fracture.

Sustainable utilization of value-added products from the catalytic and non-catalytic pyrolysis of motor car scrap tire: Suitability of produced char for energy generation and sugar mill wastewater treatment

Clean fuel and sustainable energy utilization are essential requirements to address the impacts of global warming and climate change. In this study, the pyrolysis of motor car scrap tire was investigated in a fabricated cylindrical stainless steel reactor, operated at 450, 500, and 550 °C for 50 min with or without the addition of a catalyst. The catalytic condition yielded maximum char of 59% w/w obtained at 450 °C. The addition of the catalyst also enhanced oil yield up to 33% w/w at 500 °C while the maximum gas fraction of 44% w/w was obtained under the non-catalytic condition, at 550 °C. The TGA/DSC analysis showed that the pyrolysis char had a specific heat capacity (Cp) of 35 J/g.K, relating to its high thermal stability for applications in furnaces, reactors, and heat construction materials. The char, after chemical activation, with the XRD analysis, showed that the produced activated carbon (AC) has a good crystalline structure (with high interplanar distances). The BET analysis revealed that the AC has a high surface area of 1065 m2/g (average pore diameter of 3.36 nm) which enhanced the adsorption capacity of the AC to about 90 % efficiency for the removal of the heavy metal, cadmium, from sugar mill wastewater.

An apparatus to measure thermal conductivity of ceramic pebble beds under uniaxial compressive stress

Pebble beds have various applications in many industrial and research sectors. Lithium ceramic pebble beds have specific application in fusion reactors as one of the most promising candidates for tritium breeding material. During the operation of the fusion reactor, these pebble beds will have to sustain various thermal and mechanical stresses. Therefore, it is necessary to do thermal characterisation of these pebble beds under different stress conditions and generate sufficient data on their thermal properties, which is essential for designing breeder units of fusion reactors. In this work, an apparatus has been designed to evaluate the thermal conductivity of ceramic pebble beds under compressive stress. It can be mounted to any standard universal testing machine with the necessary adjustments. The apparatus is based on the transient hot-wire method, widely used to evaluate the thermal conductivity of porous materials. A platinum wire with a diameter of 0.5 mm was used as a hot-wire. Instead of utilising a thermocouple, the 4-wire approach was used to obtain the temperature. The transient temperature response of the hot-wire was obtained by applying a 7A constant current to it and monitoring the voltage drop along its 40 mm length. The thermal conductivity of the water gel was measured to assess the accuracy of the apparatus; the results showed a less than 1.5 % variation from the reference value. In this study, the thermal conductivity of Li2TiO3 pebbles was measured in an air and helium environment in different stress conditions. In an air environment, measurements were done at atmospheric pressure, whereas in a helium gas environment, they were performed at gauge pressures of 0.05 bar, 0.5 bar, and 1 bar. The measurements were conducted in two scenarios: (i) constant stress condition at 0, 3, and 6 MPa, and (ii) Cyclic loading-unloading of 0.037–3 MPa and 0.037–6 MPa. It was found that the pebble bed's thermal conductivity rose in tandem with increased compressive stress in both the helium and air environments. Pebble bed’s thermal conductivity was found to be higher in a helium gas environment than in air. The thermal conductivity of the pebble bed increased slightly with rising helium gas gauge pressure from 0.05 bar to 1 bar. This work provides a design to incorporate 4-wire temperature measurement in the hot-wire method for thermal conductivity measurement of compressed pebble beds. It also contributes to the thermal conductivity data of Li2TiO3 pebbles in cyclic stress conditions in helium and air environments.

Performance evaluation and optimization of a suspension-type reactor for use in heterogeneous catalytic ozonation

Packed fixed-bed reactors are traditionally used for heterogeneous catalytic ozonation. However, a high solid-to-liquid requirement, poor ozone dissolution, ineffective utilization of catalyst surface area, and production of large amounts of catalyst waste impede application of such reactors. In this study, we designed a suspension catalytic ozonation reactor and compared the performance of this reactor with that of a traditional fixed-bed catalytic ozonation reactor employing oxalic acid (OA) as the target contaminant. Our results showed that total O3 dissolved into the suspension reactor (117–134 mg.L−1) was much higher compared to that measured in the fixed-bed reactor (53 mg.L−1) due to a higher O3(g) interphase mass transfer rate in the suspension reactor. In accordance with the higher O3(g) interphase mass transfer, we observed a much higher proportional OA removal (32 %) compared to that achieved in the fixed-bed reactor (10%) employing an Fe-oxide catalyst supported on Al2O3 (Fe-oxide@Al2O3) in both reactors. Use of a double-layered Cu-Al hydroxide (Cu-Al LDHs) catalyst in the suspension reactor further enhanced the performance with nearly 90 % OA removal observed. Given the superior performance of the suspension reactor, we investigated the impact of operating conditions (catalyst dosage, hydraulic retention time and ozone dosage) employing Cu-Al LDHs as the catalyst. We also developed a mathematical kinetic model to describe the performance of the suspension reactor and, through use of the kinetic model, showed that O3(g) interphase transfer rate was the rate-limiting step in OA removal. Thus, improvement in ozone gas diffuser design is required to improve the performance of the suspension reactor. Overall, the present study demonstrated that suspension reactors were more effective than fixed-bed reactors for oxidation of surface-active organic compounds such as OA due to the higher ozone interphase mass transfer rate and effective utilization of the catalyst surface area that can be achieved. As such, further research on suspension reactor design and development of catalysts suitable for use in suspension reactors should facilitate large-scale application of catalytic ozonation processes by the wastewater treatment industry.

Microstructure evolution of γ-Al2O3/FeAl tritium permeation barrier coatings under 6.4 MeV Fe3+ ion irradiation

γ-Al2O3/FeAl coatings for tritium permeation barrier (TPB) application in fusion reactors were fabricated via electro-chemical deposition and selective oxidation. The TPB coatings consisted of a γ-Al2O3 scale (200 nm), an upper interlayer of FeAl (20 μm) and a lower interlayer of Fe3Al (10 μm). Their potential in-reactor performance was investigated based on 6.4 MeV Fe3+ ion irradiations at 400 °C, up to ion fluences of 1.0 × 1019 ions·m−2 and 1.0 × 1020 ions·m−2, at depth regions entailing the oxide scale and the top interlayer. Combined grazing incidence X-ray diffraction (GIXRD) and transmission electron microscopy (TEM) analysis confirmed the overall phase stability and grain structure stability in γ-Al2O3/FeAl coatings after irradiation. Cavities dominated the damage microstructure for both γ-Al2O3 and FeAl phases, but were not observed at the sub-layer interfaces. The underlying mechanisms for defect production were discussed. Finally, a brief comparison between heavy-ion and fission neutron damage effects in Al2O3-based TPB coatings is made, aiming to bring new insights on the coating integrity and performance reliability during fusion reactor operation.

Development of electron optical capabilities for manufacturing of large components by electron beam welding

Electron beam welding (EBW) is a fast process that shows promise to be used for high-productivity welding of thick-section components in the nuclear industry. Nuclear AMRC has been working for many years on developing the use of EBW for small modular reactor (SMR) applications, such as joining thick-section pressure vessel components. The major strength of EB is the single-pass process that can radically reduce fabrication times. This is also one of the major issues with EB. The stress on the welding operator is high as any error generally means failure. In chamber EB operation, such as the Pro-beam K2000 system at Nuclear AMRC, once the chamber is closed, the only interaction between the operator and the work piece is through a camera or the electron beam. Tracking features of the material or the joint line is important to gather as much information on the situation as possible. Nuclear AMRC has used the functions of the Pro-beam multimode to gain reliability during welding. The seam tracker relies on electron optical image analysis to assess the deviation of the beam from the joint line, but it is the duty of the operator to assess whether the correction should be applied. The team has demonstrated that based on the results of the seam tracker, more work is necessary before welding. It was also demonstrated that the seam tracker can be further used to align the beam/gun to the joint and assess variations in a gap in the joint or a variation of working distance for further process reliability.

Fenton-like membrane reactor assembled by electron polarization and defect engineering modifying Co3O4 spinel for flow-through removal of organic contaminants

The application of Fenton-like membrane reactors for water purification offers a promising solution to overcome technical challenges associated with catalyst recovery, reaction efficiency, and mass transfer typically encountered in heterogeneous batch reaction modes. This study presents a dual-modification strategy encompassing electron polarization and defect engineering to synthesize Al-doped and oxygen vacancies (OV)-enriched Co3O4 spinel catalysts (ACO-OV). This modification empowered ACO-OV with exceptional performance in activating peroxymonosulfate (PMS) for the removal of organic contaminants. Moreover, the ACO-OV@polyethersulfone (PES) membrane/PMS system achieved organic contaminant removal through filtration (with a reaction kinetic constant of 0.085 ms−1), demonstrating outstanding resistance to environmental interference and high operational stability. Mechanistic investigations revealed that the exceptional catalytic performance of this Fenton-like membrane reactor stemmed from the enrichment of reactants, exposure of reactive sites, and enhanced mass transfer within the confined space, leading to a higher availability of reactive species. Theoretical calculations were conducted to validate the beneficial intrinsic effects of electron polarization, defect engineering, and the confined space within the membrane reactor on PMS activation and organic contaminant removal. Notably, the ACO-OV@PES membrane/PMS system not only mineralized the targeted organic contaminants but also effectively mitigated their potential environmental risks. Overall, this work underscores the significant potential of the dual-modification strategy in designing spinel catalysts and Fenton-like membrane reactors for efficient organic contaminant removal.

High-Temperature Creep and Microstructure Evolution of Alloy 800H Weldments with Inconel 625 and Haynes 230 Filler Materials

Alloy 800H stands as one of the few code-qualified materials for fabricating in-core and out-of-core components operating in high-temperature reactors. Welding is a common practice for assembling these components; however, the selection of a suitable filler material is essential for enhancing the high-temperature creep resistance of Alloy 800H weldments in high-temperature applications. In this study, Inconel 625 and Haynes 230 filler materials were used to weld Alloy 800H plates by employing the gas tungsten arc welding technique. The high-temperature tensile and creep rupture properties, microstructural stability, and evolution of the weldments after high-temperature exposure were investigated and compared with those of Alloy 800H. The results show that both weldments exhibit enhanced tensile and creep behavior at 760 °C. The creep rupture times of the weldments with Inconel 625 filler and Haynes 230 filler materials were about two and three time longer, respectively, than those of Alloy 800H base metal when tested at 80 MPa and 760 °C. Carbides (MC and M23C6) were commonly observed in the microstructures of both the weld and base metals in the two weldments after high-temperature creep tests. However, the Inconel 625 filler weldment displayed detrimental δ and Laves phases in the fusion zone, and these precipitates could be potential sites for initiating cracks following prolonged high-temperature exposure. This study shows that the weldment with Haynes 230 filler material exhibit better phase stability and creep rupture properties than the one with Inconel 625, suggesting its potential for use as a candidate filler material for Alloy 800H for further investigation. This finding also emphasizes the critical consideration of microstructural evolutions and phase stability in evaluating high-temperature materials and their weldments in high-temperature reactor applications.

Hydride-Induced Responses in the Mechanical Behavior of Zircaloy-4 Sheets

This study aimed to investigate the impact of hydrogen content, up to 1217 ppm, on the mechanical properties of Zircaloy-4, with a particular focus on the formation and impact of hydrides. Tensile specimens were tested across a range of temperatures and hydrogen concentrations. The results revealed a pronounced ductile-to-brittle transition associated with hydride formation. When the hydrogen content in the specimens ranged between 700 and 850 ppm, a ductile-to-brittle transition was observed at temperatures of 25 °C, 50 °C, and 75 °C. At 25 °C, the ultimate tensile strength (UTS) of Zircaloy-4 linearly increased as the hydrogen concentration rose from 0 to 1217 ppm H. However, at higher temperatures, the behavior of UTS became more complex, especially in the hydrogen concentration ranges of 500–850 ppm H. Elongation (EL) in the hydrided specimens was affected by both temperature and hydrogen concentration. As hydrogen concentration increased, there was a noticeable decline in uniform EL, while non-uniform EL showed even more significant reductions. Scanning electron microscopy (SEM) analysis of the fracture surfaces revealed that quasi-cleavage features became evident when the hydrogen content reached 850 ppm H, across all tested temperatures. These findings not only provide a quantitative assessment of the safety implications of Zircaloy-4 in nuclear reactor applications but also highlight the importance of the hydrogen charging process and mechanical testing in understanding its mechanical behavior.

Highly sensitive gamma ray dosimeter based on dual-core photonic crystal fiber

This paper introduces the application of a photonic crystal fiber (PCF) sensor to be used as a gamma ray dosimeter. This paper proposes an efficient analysis of a highly sensitive surface Plasmon resonance for gamma ray dose detection in nuclear research reactors. The proposed structure makes use of a Poly-Vinyl Alcohol (PVA) polymer, which has high sensitivity to an external electric field and gamma rays making it suitable for nuclear reactor applications. At resonance frequency, the peak of spectral loss for dosimeter sensors refers to gamma irradiation dose values. Therefore, study the different geometrical parameters for the proposed PCF sensor is of significant importance to achieve high sensitivity with low spectral losses. The full-vectorial finite-element method has been used for analysis with the plane wave expansion method. The sensitivity of the suggested sensor achieves up to 0.006 µm per gamma-ray dose unit (μm/Gy) with low losses.

Toward Eco‐Friendly E‐Waste Recycling: New Perspectives on Ozone‐Assisted Gold Leaching

Global demand for more effective methods to reclaim gold from electronic waste (E‐waste) has never been greater. Alternatives to hydrometallurgical methods, such as cyanide, are still limited. This work examines utilizing ozone and chlorides to recycle Au from E‐waste. It is started with a fundamental investigation of Au dissolution processes on the extended surface of Au polycrystalline and Au nanoparticulated electrodes. An online electrochemical scanning flow cell coupled with inductively coupled plasma mass spectrometry quantifies the rates and amounts of Au leaching. Identical‐location scanning electron microscopy (IL‐SEM) further correlates dissolution events with electrode morphological changes. It is demonstrated that ozone in the electrolyte imposes an anodic potential on the electrode, leading to anodic Au dissolution. Passivation disappears when small amounts of chlorides are added to the electrolyte, significantly enhancing the leaching yield. IL‐SEM images of gold nanoparticles (NPs) before and after exposure to ozone reveal heterogeneity in NP size‐dependent dissolution, showing higher dissolution for smaller particles. An effective Au leaching procedure is further demonstrated in a lab‐scale reactor using real E‐waste where almost complete recovery of Au is achieved. This research suggests that with engineering optimization in reactor applications based on ozone‐stimulated gold, dissolution can pave the way for environmentally friendly gold recycling.

Application of Taylor Vortex Flow Reactor Enabling Precise Control of Nucleation in Reactive Crystallization

Application of Taylor Vortex Flow Reactor Enabling Precise Control of Nucleation in Reactive Crystallization