Particle Size Distribution Research Articles

Role of particle size distribution on microstructure, defects, and mechanical properties in laser-based powder bed fusion of Scalmalloy®

Abstract This study investigates the impact of particle size distribution (PSD) in Scalmalloy® powder feedstocks on the geometrical accuracy, microstructure, defect formation, and mechanical properties of test artifacts fabricated via Laser-Based Powder Bed Fusion of Metals (PBF-LB/M). Two powder feedstocks were analyzed: Powder-1, with a mean particle size of 29.30–29.72 μm and a narrower, more uniform PSD, and Powder-2, with a mean particle size of 40.80–41.53 μm and a broader, more heterogeneous PSD. Powder-2 produced artifacts with improved geometrical accuracy and surface finish but exhibited cracking in both lattice (small features) and bulk regions. Scanning electron microscopy revealed Si precipitation near cracks in the lattice regions, attributed to segregation caused by heat accumulation in thin features and the coarser, more heterogeneous PSD of Powder-2. Powder-2 samples exhibited higher strain at break during tensile testing, likely due to its lower porosity compared to Powder-1. Single-line and hatch scan results indicated no cracking for either powder, highlighting the susceptibility of small features to thermal gradients, segregation, and geometric stress concentrators. The observation of cracking exclusively in the thin features, and not in the bulk regions, underscores the artifact's utility in investigating how geometrical features influence thermal fields, microstructural evolution, and ultimately, performance in PBF-LB/M processes.

Impact of Recycled Fine Aggregate on Physical and Mechanical Properties of Green Mortar

Through research that combined green environmental protection with the resource usage of solid waste, we explored more possibilities for mortar using recycled fine aggregate (RFA) as a material. In this work, natural fine aggregate (NFA) with different proportions of RFA in mortar was produced, while maintaining the same particle size distribution. Four types of mortar were produced, with replacement ratios of 25%, 50%, 75%, and 100%, as well as a reference mortar type without RFA. A comprehensive evaluation of the mortar with different proportions was conducted, including its workability, density, capillary water absorption, compressive strength, and flexural strength. The results indicated that the compressive strength and flexural strength of mortar containing 50% RFA improve within 14 days. In addition, with increased RFA usage, the mortar’s mechanical properties decreased. The data obtained from this study will help in the application of RFA in green mortar.

Deposition and Characterization of Fluoropolymer–Ceramic (ECTFE/Al2O3) Coatings via Atmospheric Plasma Spraying

Thermal spray techniques allow coatings to be deposited from a wide range of materials with controlled thicknesses, from micrometres to millimetres. For this reason, thermal spraying can optimize performance for diverse applications across industries, ensuring strong adhesion and the durability of coated surfaces. In this work, composite ethylene chlorotrifluoroethylene/ceramic (ECTFE/Al2O3) coatings with different ceramic ratios were deposited by plasma spraying. Four coatings were produced by spraying blended powders consisting of pure ECTFE and ECTFE with 5%, 10%, and 15 wt.% Al2O3. The effect of varying the ceramic ratio on the coatings’ microstructure and properties was investigated. Morphology and particle size distributions were determined for the raw powders. The microstructural examination of the coatings showed proportional increases in Al2O3 content. An improvement in adhesion was achieved with ceramic in the coatings from 5 wt.% Al2O3. Enhanced friction coefficients were obtained with ceramic, except for 15 wt.% Al2O3. Taber abrasion tests showed a minimal influence on ceramic content.

Chickpea-Based Milk Analogue Stabilized by Transglutaminase

Plant-based milk substitutes are becoming increasingly popular in the food industry. Among different plant proteins, chickpea proteins (CP) offer unique qualities as good functional and nutritional properties, followed by pleasant taste. This study examines the ability of the production of o/w emulsions resembling milk analogue (3% w/w chickpea protein, 3% w/w canola oil) by using chickpea protein isolate with/without the enzyme transglutaminase (TG) (50 U/g of protein). As a reference material, commercial soymilk was used. The emulsions were characterized by particle size distribution, zeta potential, viscosity, and microstructure. The TG-crosslinked chickpea protein milk analogue demonstrated improved stability, characterized by enhanced zeta potential (−24.7 mV) and extended shelf life compared to chickpea protein milk analogue without TG and soymilk. Stable particle size distribution (D[3,2] 0.11–0.17 µm) and shear-thinning behaviour (viscosity values of 2.16 mPas at 300 1/s) additionally contributed to their stability and desirable viscosity. Overall, chickpea protein milk analogue crosslinked by TG presents a promising alternative to traditional and plant-based milk products, offering clean-label, functional, and shelf-stable formulations. The additional optimization of protein concentration and processing conditions could enhance the overall functionality even further.

Preparation, characterisation and pharmacokinetics evaluation of dry power inhalation formulations of Polymyxin B

Carbapenem-resistant Pseudomonas aeruginosa (CRPA) has strong invasiveness, not only causing local lung inflammation, but also capable of penetrating alveolar epithelial cells and entering the bloodstream, thereby triggering systemic infection. This study aims at develop an alternative and effective drug delivery system through the inhalation therapy to address the limitations of polymyxin B (PMB) intravenous treatment for multidrug-resistant CRPA pneumonia, such as low lung concentration and nephrotoxicity, while also achieving systemic therapeutic effects. We prepared PMB dry powder inhalers (DPIs) using air jet milling and spray drying techniques. The prepared DPIs were characterized in terms of micromorphology, geometric particle size distribution, density, flowability, and surface roughness. Furthermore, we assessed the in vitro lung deposition and antibacterial efficacy of these inhalers.To compare the systemic exposure following changes in administration routes, blood concentration measurements were conducted for different routes of administration Spherical PMB particles, measuring 3 microns in diameter, achieved the highest fine particle fraction (FPF) of 53%. When particles transition from regular shapes to irregular blocks, a decrease of 1 micron in particle size results in an approximate 20% increase in FPF. Moreover, the FPF of PMB particles combined with smooth-surfaced lactose is approximately 10% less than that of PMB particles combined with rough-surfaced mannitol. The bioavailability of PMB DPI reached a peak of 77.46% within 10 minutes. In a murine model of acute lung infection, treatment with PMB DPI significantly reduced the bacterial load in lung tissues compared to the control group, with no observed fatalities, in contrast to the outcomes of intravenous PMB administration. In summary, particles with reduced size and increased sphericity displayed a greater FPF led to enhanced therapeutic efficacy and safety.

Evaluation of a cardboard-based spacer for enhancing aerosol delivery from pressurized metered dose inhalers

Objective The current study aimed to evaluate a novel paper card-based spacer (MDI Plus) in vitro and in vivo as a cost-effective alternative to traditional spacers (AeroChamber Plus). Methodology The in-vitro part evaluated salbutamol’s aerodynamic particle size distribution (APSD) after 0, 20, 50, 120, and 200 uses of Ventolin pressurized metered dose inhaler (pMDI) when connected to MDI Plus using an Andersen cascade impactor at an inhalation flow of 28.3 L/min. The in-vivo part recruited a cohort of adult asthmatic patients. It assessed their pMDI usage and the number of training sessions to enhance their ability to use their pMDI alone and in combination with MDI Plus and AeroChamber Plus. Moreover, the amount of salbutamol deposited within the spacer devices, on the pMDI, and on the hand of the patients after 0, 20, 50, 120, and 200 uses were evaluated. Results The durability tests revealed that while there were reductions in aerodynamic performance over the lifespan of the pMDI, the decreases were insufficient to render the spacer ineffective. The fine particle fraction decreased slightly, and the mass median aerodynamic diameter increased somewhat, but the spacer maintained functional performance. The study indicated that spacers significantly improved patients' ability to use their MDIs correctly with minimal training. The MDI Plus showed a slightly significant positive impact (p < 0.05), requiring fewer training sessions for effective use. The amount left in the MDI Plus was significantly lower than within the AeroChamber Plus (p < 0.05). The amount deposited on the MDI and the hands of the patients after multiple storage in the MDI Plus box and uses was insignificant and within the allowed limits. Conclusion The MDI Plus simultaneously can act as an pMDI packaging box and spacer, serving as a practical, affordable, and accessible alternative to traditionally commercially available plastic spacers, particularly in resource-limited settings.

Source identification and characterization of water-insoluble single particulate matter in rainfall sequences

ABSTRACT Analysis of atmospheric pollutants in rainwater provides valuable information on the environmental impacts of both natural and anthropogenic pollution sources. Air pollution studies often show that particulate matter (PM) collection on filters is used for subsequent analysis. However, this approach can result in significant particle accumulation on filters and complicate their characterization by semi-quantitative analytical techniques. In this study, insoluble PM in sequentially collected rainwater samples was analyzed for particle size, morphology, and chemical composition. Scanning electron microscopy (SEM) coupled with energy-dispersive X-ray spectrometry (EDS) and a particle size analyzer were used for these analyses. By combining SEM–EDS data with particle size distribution analyses, chemical composition findings, and upper atmosphere back-orbit modeling, specific sources of insoluble particles in rainwater were identified. In addition, rainwater samples were analyzed for pH, electrical conductivity, and major anions and cations. The pH values varied from 6.19 to 7.04, while the electrical conductivity values varied from 5.35 to 83.53 μS/cm. Among the major ions, relatively high concentrations of Ca2+, SO42−, and NO3− were detected, while F−, Mg2+, Na+, and Cl− were observed in lower concentrations. The contributions of sea salt were evidenced by the presence of Cl− and Na+ ions.

A Novel Optical Instrument for On-Line Measurement of Particle Size Distribution—Application to Clean Coal Technologies

A flow cell is a critical measurement interface for many optical instruments. However, the flows are often sampled under harsh conditions, such as under high pressure and/or high temperature, in the presence of particles, moisture, vapors with high dew points or corrosive gases. Therefore, obtaining a high-optical-quality flow cell that does not perturb the measurement is a significant challenge. To address this challenge, we proposed a new flow cell that employs a unique laminar coaxial flow field (for the purge and sample flows). A test system was built to conduct particle size distribution (PSD) measurements with no sampling bias using a state-of-the-art analyzer (Malvern Panalytical Insitec). The results revealed that the measurement zone is well defined solely by the sample flow, and the optical windows are well protected by the purge flow, with minimal risk of any depositions from the sample flow. Using this flow cell, the Insitec can successfully measure PSD under high pressure and temperature under moist, corrosive conditions without generating any sampling bias. Importantly, we successfully applied this flow cell for on-line PSD measurement for the flue gas of a 100 kWth pressurized oxy-coal combustor operating at 15 bara.

Investigating the Influence of Crospovidone's Manufacturer Variability on Dissolution Profiles of Hydrochlorothiazide Tablets.

This study examines the influence of crospovidone (CP) manufacturer variability on the dissolution profiles of hydrochlorothiazide (HCTZ) tablets. Four CP batches from different manufacturers were characterized using pharmacopeial and physicochemical tests, including infrared absorption, loss on drying, and scanning electron microscopy (SEM). Significant differences were observed in the particle size distribution, wetting time, and water absorption capacities of the CP batches. Tablets were formulated using both direct compression and wet granulation methods. For the latter, the superdisintegrant was either added to the binder solution or incorporated intra- or extra-granularly. Disintegration and dissolution tests revealed that both CP concentration and the method of incorporation significantly affected tablet performance. Poly Kovidone and Max-Povidon exhibited superior performance at lower concentrations, while differences between brands became less pronounced at higher concentrations. The extra-granular method notably enhanced drug release profiles. Statistical analyses, including f2 similarity factors and MANOVA with Principal Component Analysis (PCA), highlighted significant differences in dissolution behavior among the formulations. These findings emphasize the importance of controlling excipient variability to ensure consistent product performance. The study concludes that a 2% CP concentration is optimal for mitigating source variability and that the extra-granular addition of CP in wet granulation is recommended for enhancing its functional properties.

Rheology of concentrated crystal suspensions: sucrose fondants as hard particles in soft matter

Hard particle dispersions are abundant in food as well as technical applications. In particular, the production of many candies like fondants, crystalline sugars or creamed honeys involves agitation of concentrated suspensions of microscopic crystals in saturated solutions. However, the complex rheological behavior of such non-colloidal suspensions with poly-disperse, irregular particles is not fully understood. This work investigates different sucrose suspensions with a particle volume fraction of about 50%. After detailed image analysis of the varying particle size distributions and shapes, the flow properties are investigated by oscillatory rheology. Amplitude sweeps, frequency sweeps and thixotropy tests show the dependency of rheological behavior on the microstructure of the suspensions. In particular, all samples show characteristic strain softening with subsequent strain hardening that indicates jamming at large strains. This is observed irrespective of specifics in the particle shape and material, suggesting universal behavior due to the high particle volume fraction. They also show significant time-dependent behavior. However, sedimentation rates are higher and structure rebuilding is lower for larger particle sizes and dispersity. The observed strain softening and structure rebuilding are explained by rearrangement of the crystals: Under moderate strain amplitudes, friction and collisions are minimized, with a larger optimization potential for larger dispersities. When oscillations are reduced again, mainly small particles re-arrange in an arbitrary order over time, leading to an increase in loss and storage modulus and thus thixotropic behavior. This time-dependent process needs to be taken into account when measuring or processing concentrated crystal suspensions. Our findings contribute to a better understanding of concentrated suspensions simple in composition, but complex in their flow properties. The observed behavior strongly depends on the particle-particle interactions. Thus, our findings can be transferred to other areas involving concentrated, non-Brownian frictional suspensions of compact hard particles, as they are often found in food, technical applications or geology.

Direct observation of Arctic Sea salt aerosol production from blowing snow and modeling over a changing sea ice environment

In the polar regions, there is significant model bias in the number concentrations and seasonality of sea salt aerosol (SSA) due to the lack of understanding of aerosol sources associated with sea ice, which is hampering accurate climate forecasts at high latitudes. Recently, SSA originating from the sublimation of blowing snow has been directly observed to be an important source of aerosol particles in the Antarctic during winter/spring, validating a mechanism proposed a decade ago. Here, we report in situ observations of coarse aerosol production (particle diameter 0.5–20.0 µm) dominated by sea salt from blowing snow above sea ice during winter/spring in the Central Arctic during the MOSAiC (Multidisciplinary drifting Observatory for the Study of Arctic Climate) expedition from October 2019 to September 2020. Blowing snow conditions occurred 20–40% of the time during each of the months from December 2019 to April 2020, with a total of 26 blowing snow events. During blowing snow periods, coarse aerosol number concentrations increased often by an order of magnitude compared to no-blowing snow periods. Mass fractions of sodium chloride in sub-micron aerosol (particle diameter 0.01–0.625 µm) available during December 2019 and 10 m wind speed showed a significant correlation (R = 0.61, P &amp;lt; 0.05), indicating that much of the aerosol observed during storms is sea salt released by sublimating blowing snow. We use these observations to refine the current model parameterization by considering the spatial and temporal variability of atmospheric and sea ice conditions. Snow particle size distributions and snow salinities are expressed as a function of wind speed and snowpack depth, respectively, which can be easily implemented into climate models. Validation of the snow particle size distribution parameterization with previous polar winter observations showed agreement in the Arctic (N-ICE2015 cruise, March 2015) above the threshold for drift and blowing snow, but a negative bias in the Antarctic (Weddell Sea, June to August 2013). Updating the blowing snow mechanism in the chemical transport model p-TOMCAT with wind-dependent snow particle size distributions results in 14% more SSA produced and a slightly better correlation with MOSAiC observations of coarse aerosol (R = 0.28). Significant increases in aerosol number concentration due to blowing snow sublimation are calculated by as much as 70 cm−3 during the Antarctic winter and 50 cm−3 during the Arctic winter compared to a baseline simulation with no blowing snow. Thus, taking into account SSA from blowing snow above sea ice will be important to improve model predictions of polar aerosol and climate.

Predicting bulk density in Brazilian soils for carbon stocks calculation: a comparative study of multiple linear regression and Random Forest models using continuous and categorical variables

Soil bulk density (ρb) is vital for assessing soil organic carbon (SOC) and nutrient stocks, as well as for modeling soil processes. Although ρb can be measured using traditional methods, these are labor-intensive and time-consuming. Consequently, there is a growing interest in developing pedotransfer functions (PTFs) to predict ρb based on more easily measured soil properties. The vast Brazilian territory, with different climates and biomes, presents a challenge for development of national-scale PTFs, particularly for ρb. In this study, a comprehensive dataset was compiled from various sources to develop ρb PTFs across Brazil. The dataset includes particle size distribution (PSD), SOC, ρb, sampling depth, soil order, land use, and geographic coordinates, allowing for the incorporation of additional numerical and categorical variables. Rigorous data preprocessing ensured quality and reliability. PTFs were developed using multiple linear regression (MLR) and Random Forest (RF) models. Model accuracy was evaluated using mean absolute error, bias, root mean square error (RMSE), and coefficient of determination. Both MLR and RF models accurately predicted ρb, with log-transformed PSD and SOC emerging as key predictors. The RF model slightly outperformed the MLR model (RMSE = 0.12 vs. 0.13 g cm−3) on the test dataset, underscoring the importance of environmental and categorical variables in predicting ρb. The developed PTFs, along with other PTFs for Brazil, were applied to estimate SOC stocks across different biomes and land uses. Best estimations were obtained with the RF model, with an R2 of 0.97, emphasizing the value of categorical variables in improving SOC stock estimations.

Satellite estimation of the spectral power exponent of particulate backscattering coefficient in the global ocean

The spectral power exponent of the particulate backscattering coefficient (bbp), η, is a crucial parameter for assessing particle size distribution in the ocean, particularly for high-precision estimation of marine biogeochemical cycles. The development of remote sensing inversion models for η has been constrained by insufficient in situ data or faulty model mechanisms. In this study, biogeochemical Argo (BGC-Argo) data were effectively utilized to address the limitations of traditional observations, and the superior XGBoost method was employed to construct a global ocean η remote sensing inversion model (XGB model). In the 5-fold cross-validation, the Pearson correlation coefficient (R), root mean square error (RMSE), mean absolute error (MAE), and median absolute percentage deviation (MAPD) of the XGB model remained stable at approximately 0.65, 0.3, 0.25, and 16%, respectively, demonstrating high robustness. Via independent sample verification and comparison with major inversion models from the literature, the XGB model exhibited a high R value of 0.66 and the lowest RMSE, MAPD, and MAE, with values of 0.33, 16.81%, and 0.25, respectively, indicating its superior inversion capability. High η values were primarily found in oligotrophic regions and the iron-limited Southern Ocean, whereas low values were observed in coastal waters, exhibiting seasonal variation. The distribution of η in other ocean areas remained relatively stable, with nonsignificant seasonal changes. This study demonstrates the significant contributions of BGC-Argo observations in enhancing remote sensing estimation of global ocean η values, thereby providing valuable support for biogeochemical cycling research.

Time-Lapse Imaging of Bismuth Precipitation and Coarsening on the Surface of Sn-Ag-Cu-Bi Solder Joints After Thermal Cycling

Abstract Adding bismuth to Sn-Ag-Cu solder compositions can significantly improve reliability in thermal cycling, but there are uncertainties in how bismuth precipitates and coarsens in Sn-Ag-Cu-Bi solders containing &gt; 3 wt.% Bi. Here we apply time-lapse imaging in a scanning electron microscope to study bismuth precipitation and coarsening at room temperature on the polished surface of Sn-2.25-0.5Ag-6Bi ball grid array solder joints after thermal cycling. It is shown that (Bi) precipitates on the surface within 2 h after polishing and then coarsens by a combination of Ostwald ripening, coalescence ripening, and competition between two orientation relationships. Time-lapse imaging revealed that coalescence causes an increase in the local bismuth particle size and the formation of anomalously large (Bi) particles. The accumulation of bismuth on the polished surface increases far beyond the equilibrium volume fraction for this alloy. The bismuth particle size distributions are significantly wider than expected from Lifshitz–Slyozov–Wagner (LSW) theory, that assumes only Ostwald ripening, which is shown to be because coalescence creates anomalously large particles. This study shows the important role of bismuth precipitate coalescence within the coarsening mechanism in Sn-2.25-0.5Ag-6Bi solder joints.

The sedimentation probability model based on the particle size distribution and cake morphology in the cross-flow membrane process

Evolution of non-uniform cake structure in the cross-flow membrane process was investigated in this study. Considering the real cake surface morphology and particle size distribution, the sedimentation probability of foulant (γ) was calculated, then a new flux prediction model based on the mass conservation on the cake surface was proposed. Results showed that the predictions of the new model had excellent agreements with experimental data (R2 > 0.97), wherein cake surface heights obeyed normal distribution and protrusion heights approximately obeyed exponential distribution. Meanwhile, γ decreased with cross-flow velocity from 4.59 % (0.24 m/s) to 2.53 % (0.48 m/s), whereas γ increased with trans-membrane pressure from 2.80 % (0.1 MPa) to 6.44 % (0.2 MPa). In addition, a skin layer which was approximately about 20 % of total cake thickness but possessed 70 % of the total resistance, was also observed in the cross-flow mode. These results provided a brand-new perspective (tuning cake morphology or structure) on the essence of membrane fouling alleviation.

Assessment of the Applicability of Waste Concrete Fine Powder as a Raw Material for Cement Clinker

The cement industry is responsible for a significant portion of global CO2 emissions, primarily due to the decarbonatization of limestone during clinker production. To mitigate this environmental impact, this study investigated the feasibility of using waste concrete fine powder, produced during the recycling of waste concrete, as a decarbonized raw material in cement clinker production. As a decarbonized material, waste concrete fine powder presents a valuable opportunity to reduce CO2 emissions typically produced during the decarbonatization of limestone in clinker production. In addition, its use supports the recycling of construction waste, contributing to both emissions reduction and resource sustainability. In this study, samples were collected from 20 intermediate treatment plants in South Korea, where the chemical composition, particle size distribution, and carbonation rate of the fine powders were analyzed. The experimental results show that the properties of waste concrete fine powder vary significantly depending on the recycling process. Road construction aggregate production plants, which typically involve two to three crushing stages, produce fine powders with higher CaO content (28–31%) and consistent particle size distributions. In contrast, plants producing aggregates for concrete, which involve four to six crushing stages, produce powders with lower CaO content (around 20%) and greater variability in particle size. The average carbonation rate of 7.44% suggests that these fine powders can replace limestone in clinker production. It is estimated that substituting 5% of limestone with waste concrete fine powder could reduce CO2 emissions from limestone decarbonatization by approximately 952,560 tons in 2023, representing a 3.34% decrease in total emissions from clinker production. However, it is important to note that the CO2 emissions reduction calculation is not from a lifecycle perspective, without considering the energy-related emissions from recycling waste concrete fine powder. Nevertheless, this study highlights the potential for waste concrete fine powder to serve as a sustainable raw material for the cement industry, contributing to both CO2 reduction and efficient recycling of construction waste.

Thiol-Assisted Regulated Electronic Structure of Ultrafine Pd-based Catalyst for Superior Formic Acid Electrooxidation Performances

In order to further boost the electrocatalytic performances of small organic molecule oxidation and maintain the structure stability of Pd-based catalyst during long cycle, a new ligand compound (i.e. propanethiol) was introduced into the Pd/C anode catalyst to prepared Pd/C-SH catalyst by two main steps of propanethiol adsorbed on Vulcan XC-72 carbon (C-SH) by water bath impregnation method and Pd nanoparticles anchored on the functionalized C-SH support by improved liquid reduction method. Results showed that the Pd nanoparticles with high dispersion in Pd/C-SH catalyst were obtained and their particle size distribution was in the range of 1.6-4.8nm. Moreover, Pd particle size became smaller with the modification of propanethiol, indicating that propanethiol could facilitate the formation of smaller Pd. Electrochemical measurements showed that the mass activity of Pd/C-SH (1229mAmg-1) was 4.6 times that of Pd/C (267mAmg-1) towards formic acid oxidation. Higher stability (30 times higher than Pd/C) and more faster charge transfer kinetics of oxidation reaction were also recorded for Pd/C-SH catalyst. The enhancement of electrochemical performances of Pd/C-SH catalyst might be related to highly dispersed Pd with reduced particle size, adjusted electronic structure of Pd as well as maintained stable Pd structure and particle size.

Gasification-MILD combustion technology with ash-sludge recirculation for reducing multi-phase net dioxin discharges from a waste incineration.

This study addresses the challenge of reducing "net" toxic pollutant discharge, specifically dibenzo-p-dioxins and dibenzofurans (PCDD/Fs), while minimizing the energy consumption and costs associated with detoxification. Our research focuses on reintroducing fly ash and scrubber sludge (ASR) into a hazardous waste thermal treatment system equipped with gasification-intense low oxygen dilution (GASMILD) and an advanced air pollution control system (APCS). This approach yielded a remarkable PCDD/F removal efficiency exceeding 99.9% for both mass and toxic equivalent (TEQ), achieving a net destruction of PCDD/Fs within the system. The success can be attributed to the ASR material's richness in ultrafine particles, which act as nucleation cores during combustion, promoting particle growth and enhancing the capture of PCDD/Fs in the APCS. This leads to a significant reduction (over 93%) in both PCDD/F mass and World Health Organization-toxic equivalent (WHO-TEQ) concentration in the flue gas. While a phase transition of gaseous PCDD/Fs within the APCS caused a shift in the particle size distribution towards larger particles, the overall PCDD/F mass concentration in the stack emissions remained lower with ASR. Notably, the reintroduced PCDD/Fs tend to deposit in the nasal region of the respiratory tract, potentially reducing the health risks associated with deeper lung deposition. This research demonstrates the effectiveness of ASR in achieving net PCDD/F destruction within a GASMILD combustion system, offering a promising strategy for cleaner and more sustainable waste management practices. From a managerial perspective, this approach provides a cost-effective solution for PCDD/F mitigation, contributing to reduced emissions and improved public health.

State-enhanced attention network for optimisation of energy and yield in gas atomised metal powder production

Gas atomisation is a widely used technique for producing spherical metal powder feedstock for additive manufacturing. However, the process parameters suffer from variability and inefficiency in balancing powder yield, energy consumption, and particle size distribution. Optimising these complex, interdependent parameters pose a significant challenge. This work proposes a novel State-Enhanced Attention Network architecture in a framework that simultaneously optimises yield and energy consumption during nitrogen gas atomisation for sustainable metal powder production. The novelty lies in integrating processed long-term memory states with the attention mechanism, enabling nuanced attention weighting. This allows the model to leverage global sequence context and recent state information for improved yield and energy predictions. The proposed network is trained and integrated into a non-dominated sorting genetic algorithm to enable multi-objective optimisation. This framework evolves a set of Pareto-optimal solutions that balance trade-offs between maximising yield and minimising energy consumption. The approach is evaluated using augmented real-world data from an industrial gas atomisation plant. The proposed model demonstrates significantly improved predictive accuracy on real-world datasets, compared with baseline deep learning models. Results highlight the capabilities of the proposed technique for automated, data-driven optimisation of gas atomisation, simultaneously improving yield, energy efficiency, quality control, and sustainability. The integrated deep learning and evolutionary optimisation framework also provides an innovative solution for enhanced control of additive manufacturing powder production processes.

Development of hot melt extruded Polycaprolactone (PCL) matrices for an oral ultra-long-lasting delivery of Galantamine for Alzheimer’s disease therapy

Galantamine Hydrobromide (GAL) is a tertiary alkaloid, acting as a competitive and reversible cholinesterase inhibitor. It is indicated for the symptomatic treatment of patients from mild to moderate dementia level of the Alzheimer’s disease (AD) type. For treatment of mild to moderate AD, GAL is generally combined with other drugs. The purpose of this work was development and characterization of hot melt extruded (HME) matrices based on polycaprolactone (PCL) for GAL oral ultra-long-lasting delivery. PCL is biodegradable polymer, biocompatibility, water-insoluble and excellent for HME process. From HME drug and polymer mixtures arms from 1 % up to 50 wt-% of GAL were obtained. The raw materials and the as-obtained HME arms were characterized by particle size distribution (PSD), differential scanning calorimetry (DSC), scanning electron microscopy (SEM), wide angle x-ray scattering (WAXS) and dissolution test. Our findings showed that GAL possesses crystalline form I polymorphic, it is thermodynamically stable, and remains their particle and crystalline form even after HME process. Crystallization temperature of PCL increases with GAL content, indicating strong heterogeneous nucleating effect of drug on polymer crystallization process. SEM morphological analysis indicates continuous polymeric phase on surface. However, higher amounts of GAL (50/50 wt-%) presented clusters and heterogeneity, especially in extruded cross-section. It may have influenced the drug release property, decreasing the sustained release ability, due to the transport of medium molecules through the bulk extrudates by GAL soluble clusters. The diffractograms (WAXS) showed patterns peaks of GAL and PCL, indicating that GAL remains its crystalline structure and PCL recrystallized. In the dissolution test, PCL/GAL 80/20 and 90/10 achieved 100% with over seven days and profiles that can be tuned by varying GAL concentration. Finally, we demonstrate the feasibility of using HME process based on the mixture of PCL and GAL as proposals for oral therapies for conditions of AD. This is the first report showing PCL-GAL polymer matrices that achieves several-days drug release.