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8 pages, 1351 KB

Open AccessProceeding Paper

Application of an Adaptive Neuro-Fuzzy Inference System for the Removal of Cadmium (II) from Acid Mine Drainage onto Modified Cellulose Nanocrystals

by Banza Jean Claude, Vhahangwele Masindi and Linda L. Sibali

Eng. Proc. 2025, 117(1), 1; https://doi.org/10.3390/engproc2025117001 - 18 Nov 2025

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Abstract

This research utilizes a modified cellulose nanocrystal composite as an adsorbent to remove cadmium (II) through a column study. A fixed-bed column was used to remove cadmium (II) at room temperature using varying process factors, such as pH (4–8), bed height (3–9 cm), [...] Read more.

This research utilizes a modified cellulose nanocrystal composite as an adsorbent to remove cadmium (II) through a column study. A fixed-bed column was used to remove cadmium (II) at room temperature using varying process factors, such as pH (4–8), bed height (3–9 cm), flow rate (3–7 mL/min), and concentration (10–20 mg/L). According to these findings, cadmium (II) breakthrough occurred more quickly at lower bed heights, higher flow rates, and higher cadmium (II) concentrations. The Thomas model is the most appropriate kinetic model. Deep learning models, such as the adaptive neuro-fuzzy inference model with two algorithms (backpropagation and least squares estimation), were effectively used to model the effectiveness of cadmium (II) removal in aqueous solutions via modified cellulose nanocrystals. To compare the model’s predicted results with experimental data, statistical approaches were employed, including calculating the coefficient of determination (R²) and mean square error (MSE). The ANFIS model used to predict cadmium (II) adsorption via modified cellulose nanocrystals had a strong correlation value of 0.997 for least squares estimation (LSE) and 0.999 for the gradient descent (backpropagation) method, indicating the effectiveness of the trained model in predicting the cadmium (II) adsorption process. Full article

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8 pages, 1416 KB

Open AccessProceeding Paper

Enzyme-Assisted Extraction of Bioactive Compounds from Origanum dictamnus L.

by Zafeiria Lemoni, Roza Konstantina Leka, Theopisti Lymperopoulou and Diomi Mamma

Eng. Proc. 2025, 117(1), 2; https://doi.org/10.3390/engproc2025117002 - 19 Nov 2025

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Abstract

Enzyme-assisted extraction (EAE) was applied to extract bioactive compounds from the leaves of Origanum dictamnus L. using the commercial enzyme preparation Cellic^® CTec3 HS. A Taguchi experimental design was applied to determine the optimal EAE conditions. The variables were enzyme loading, solid-to-liquid [...] Read more.

Enzyme-assisted extraction (EAE) was applied to extract bioactive compounds from the leaves of Origanum dictamnus L. using the commercial enzyme preparation Cellic^® CTec3 HS. A Taguchi experimental design was applied to determine the optimal EAE conditions. The variables were enzyme loading, solid-to-liquid ratio, extraction time and the responses of total phenolic content (TPC), and total flavonoid content (TFC). Under optimized conditions, EAE achieved TPC yield of 164.8 ± 5.2 mg GAE/g and TFC yield reached 92.5 ± 5.7 mg CAE/g. The results support the potential of EAE as an efficient method for extraction of bioactive compounds from Origanum dictamnus L. Full article

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8 pages, 1880 KB

Open AccessProceeding Paper

Design and Integration of a Retrofit PV–Battery System for Residential Energy Savings and Thermal Comfort

by Dimitrios Rimpas, Nikolaos Rimpas, Vasilios A. Orfanos and Ioannis Christakis

Eng. Proc. 2025, 117(1), 3; https://doi.org/10.3390/engproc2025117003 - 26 Nov 2025

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Abstract

This study presents the design and implementation of a prototype dual-function photovoltaic window system that integrates flexible solar panels for dynamic shading and a compact lithium battery for local energy storage. The methodology involves developing an experimental setup where translucent, flexible photovoltaic panels [...] Read more.

This study presents the design and implementation of a prototype dual-function photovoltaic window system that integrates flexible solar panels for dynamic shading and a compact lithium battery for local energy storage. The methodology involves developing an experimental setup where translucent, flexible photovoltaic panels are retrofitted onto a standard residential window. The system is connected to a charge controller and a small-capacity lithium-ion battery pack. Key performance metrics, including solar irradiance, power generation efficiency, reduction in thermal transmittance, and battery state of charge, are continuously monitored under varying real-world environmental conditions. The integrated panels can significantly reduce solar heat gain, thereby lowering indoor ambient temperature and reducing the building’s cooling load. Simultaneously, the system will generate sufficient electricity to be stored in the lithium battery, providing a self-contained power source for low-draw applications such as lighting or charging personal devices. This research highlights the viability of developing cost-effective, multi-functional building components that transform passive architectural elements into active energy-saving and power-generating systems in terms of green environment goals. Full article

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10 pages, 2322 KB

Open AccessProceeding Paper

Photocatalytic Activity of ZnFe₂O₄ for the Degradation of Fast Green FCF and Orange II

by Nashra Fatima, Ekhlakh Veg, Srishti Dwivedi, Anushka Pandey and Tahmeena Khan

Eng. Proc. 2025, 117(1), 4; https://doi.org/10.3390/engproc2025117004 - 28 Nov 2025

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Abstract

In recent years, photocatalysis using semiconductor materials has gained significant attention as an effective strategy for dye degradation under mild conditions. Among various metal oxide photocatalysts, zinc ferrite (ZnFe₂O₄) has gained attention due to its narrow band gap, good [...] Read more.

In recent years, photocatalysis using semiconductor materials has gained significant attention as an effective strategy for dye degradation under mild conditions. Among various metal oxide photocatalysts, zinc ferrite (ZnFe₂O₄) has gained attention due to its narrow band gap, good stability, low cost, and activation under visible light. ZnFe₂O₄ nanoparticles (NPs) were synthesized using a co-precipitation process and tested for their photocatalytic effectiveness in degrading synthetic dyes Fast Green FCF and Orange II Sodium Salt under visible light. This study emphasizes the benefits of utilizing ZnFe₂O₄ as a visible light-activated, cost-effective, and environmentally friendly photocatalyst. These findings add to the growing research on wastewater treatment options. Full article

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8 pages, 3444 KB

Open AccessProceeding Paper

Biowax Impregnation of Recyclable Packaging Papers with Enhanced Water and Oil Barrier Properties

by Pieter Samyn

Eng. Proc. 2025, 117(1), 5; https://doi.org/10.3390/engproc2025117005 - 3 Dec 2025

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Abstract

The industrial processing of innovative packaging papers with enhanced barrier properties has become ever more challenging due to the more stringent regulations on single-use plastics (SUPs), with an extended applicability to coated papers. Although the traditional packaging papers are based on renewable sources, [...] Read more.

The industrial processing of innovative packaging papers with enhanced barrier properties has become ever more challenging due to the more stringent regulations on single-use plastics (SUPs), with an extended applicability to coated papers. Although the traditional packaging papers are based on renewable sources, they do not provide water and oil resistance and traditionally require the deposition of extruded polymer films or dispersion coatings that interfere with the paper recycling process. In this study, an alternative method has been investigated through the impregnation of papers with various types of biowax, including a synthetic PE wax, palm oil wax, sunflower wax, rice bran wax, rapeseed wax, castor wax, rice bran wax, and candelilla wax. The close control of processing conditions in an industrial pilot-line is critical to produce an optimized product quality with enhanced water and oil contact angles. In particular, the variations in wax type and wax loadings after single- or dual-side impregnation and the control of processing temperatures have been related to the oil and water contact angles. The stable water contact angles in the range of 100 to 120° were obtained depending on the biowax type. Meanwhile, the increase in oil contact angles up to 60° is in line with the enhanced grease resistance. The good recyclability scores of biowax-impregnated papers were demonstrated following the “Harmonized European laboratory test method to generate parameters enabling the assessment of the recyclability of paper and board products in recycling mills with conventional process (Part I)”, version February 2024. Full article

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8 pages, 425 KB

Open AccessProceeding Paper

Electrified Pressure Swing Distillation: A Systems-Based Sustainability Assessment

by Jonathan Wavomba Mtogo, Gladys Wanyaga Mugo, Emmanuel Karimere Kariuki, Martin Murimi Gichungu and Bevin Nabai Kundu

Eng. Proc. 2025, 117(1), 6; https://doi.org/10.3390/engproc2025117006 - 3 Dec 2025

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Abstract

The decarbonisation of energy-intensive separation processes is critical for achieving net-zero goals in the chemical industry. While widely used for separating azeotropic mixtures, pressure swing distillation (PSD) remains highly energy-intensive due to significant thermal demands. This work presents a comprehensive systems-based assessment of [...] Read more.

The decarbonisation of energy-intensive separation processes is critical for achieving net-zero goals in the chemical industry. While widely used for separating azeotropic mixtures, pressure swing distillation (PSD) remains highly energy-intensive due to significant thermal demands. This work presents a comprehensive systems-based assessment of electrified distillation designs, with a specific focus on tetrahydrofuran–water separation as a case study. Using Aspen Plus and Aspen Plus Dynamics, key performance indicators, including controllability, thermal and exergy efficiencies, and CO₂ emissions reduction potential, are evaluated. The electrified configurations employed heat pumps as substitutes for conventional steam heating. Disturbance rejection was applied to compare the input–output pairings and select pairings with the best controllability and disturbance rejection indices. Results showed that the conventional PSD (CPSD) exhibited higher Morari Resiliency Index (MRI) and acceptable Condition Number (CN) values, indicating better robustness and disturbance rejection than the heat pump-assisted PSD (HPAPSD). Despite this, HPAPSD achieved a 59% reduction in primary energy demand, a 23% increase in exergy efficiency, and an 82% reduction in CO₂ emissions. This study demonstrates the potential of electrification to transform PSD systems from rigid, energy-intensive operations into flexible and sustainable processes. The findings support a shift towards integrated, systems-driven design strategies in chemical separation, aligning with broader goals in process electrification, circularity, and net-zero manufacturing. Full article

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15 pages, 534 KB

Open AccessProceeding Paper

Modelling Rabies Transmission with Vaccination: Incorporating Pharmaceutical and Particle Processing for Pre-Exposure Prophylaxis Optimization

by Kuppusamy Anjali, Thangaraj Nandha Gopal, Thangavel Megala, Anbulinga R. Ashwin and Arunachalam Yasotha

Eng. Proc. 2025, 117(1), 7; https://doi.org/10.3390/engproc2025117007 - 3 Dec 2025

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Abstract

Rabies remains a persistent zoonotic threat, particularly in regions where domestic dogs are the main source of human and animal infections. This mathematical model studies the dynamics of rabies transmission between canine populations (dog-to-dog) and from canines to humans (dog-to-human). The model incorporates [...] Read more.

Rabies remains a persistent zoonotic threat, particularly in regions where domestic dogs are the main source of human and animal infections. This mathematical model studies the dynamics of rabies transmission between canine populations (dog-to-dog) and from canines to humans (dog-to-human). The model incorporates susceptible, infected, and vaccinated compartments for both species, with pre-exposure vaccination as the key control strategy. Processes such as encapsulation, stability enhancement, and controlled release are modelled as parameters influencing vaccination rates in both dogs and humans. Specifically, the model introduces processing-dependent vaccination functions that reflect improved bioavailability, immunogenicity, and delivery efficiency due to advanced formulation techniques. This interdisciplinary approach bridges mathematical epidemiology and pharmaceutical technology. Earlier rabies models focus on transmission and static vaccination, often ignoring vaccine formulation and delivery. Our current work fills this gap by incorporating pharmaceutical and particle engineering parameters into the vaccination terms of the model, thereby providing a more comprehensive framework for optimizing rabies control strategies in endemic regions. Positivity and boundedness analyses confirm that all model variables remain biologically feasible and bounded over time. Stability analysis identifies thresholds for disease elimination or persistence. Numerical simulations show that enhancing pharmaceutical parameters increases vaccination impact, reducing peak infection prevalence in dogs from 18% to 5% and in humans from 4% to 0.8%, and shortening elimination time from 8 years to 3 years. Formulations with controlled release and improved stability maintain over 90% reduction in transmission for more than 5 years, compared to 60% over 3 years for conventional vaccines. This will ensure that the model’s predictions are validated against realistic conditions and can effectively guide rabies control strategies. Full article

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8 pages, 2412 KB

Open AccessProceeding Paper

Facile Wet-Chemical Synthesis of Graphene Oxide-Hydroxyapatite Composite for Potent, Accelerated and Synergistic Sonophotocatalytic Degradation of Diclofenac Under Light and Ultrasound Irradiation

by Joe Mari Biag, Justin Carl Briones, Crystal Cayena Dancel, Florely De Villa, Christian Ibarra Durante, Rugi Vicente Rubi and Rich Jhon Paul Latiza

Eng. Proc. 2025, 117(1), 8; https://doi.org/10.3390/engproc2025117008 - 3 Dec 2025

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Abstract

The widespread disposal of pharmaceutical waste, particularly diclofenac (DCF), poses a significant threat to aquatic ecosystems. The current degradation methods, including biological treatments and standalone advanced oxidation processes, often prove insufficient, leaving residual DCF concentrations. This study proposes a novel solution using a [...] Read more.

The widespread disposal of pharmaceutical waste, particularly diclofenac (DCF), poses a significant threat to aquatic ecosystems. The current degradation methods, including biological treatments and standalone advanced oxidation processes, often prove insufficient, leaving residual DCF concentrations. This study proposes a novel solution using a rapidly synthesized graphene oxide/hydroxyapatite (GO/HAp) nanocomposite via wet-chemical precipitation to enhance DCF degradation through synergistic sonophotocatalysis. The synthesized nanocomposite’s structure was confirmed using Fourier transform infrared spectroscopy FTIR, x-ray diffraction XRD, and scanning electron microscope SEM analyses, revealing the successful formation of a hexagonal HAp phase on GO sheets. Optimization of the sonophotocatalytic parameters revealed that pH and loading significantly influenced degradation, while time had a less pronounced effect. The optimal conditions (a pH pf 4, 45 mg GO/HAp, 30 min) achieved a remarkable 93.86% DCF degradation, significantly outperforming standalone photocatalysis (72.76%) and sonolysis (63.76%). This enhanced performance is attributed to the synergistic effect of sonophotocatalysis, which increases the active surface area and radical generation, coupled with the high surface area and adsorption capacity of the GO/HAp nanocomposite. This research demonstrates that rapid wet-chemical synthesis of the GO/HAp nanocomposite, coupled with an optimized sonophotocatalytic process, offers a potent, accelerated, and efficient method for degrading DCF, paving the way for improved pharmaceutical wastewater treatment. Ultimately, this research provides a foundation for developing effective water treatment solutions to combat pharmaceutical contaminants. Full article

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10 pages, 2356 KB

Open AccessProceeding Paper

Nitrogen-Doped Carbon Dots Derived from Onion Peel (Allium cepa) for Fluorescence-Based Detection of Microplastics

by Ma. Sofia Sam Pintoy, Fayeeh Joy Dabalus, Joemari Voluntad, Carlou Eguico, Allan N. Soriano, Nathaniel P. Dugos and Rugi Vicente Rubi

Eng. Proc. 2025, 117(1), 9; https://doi.org/10.3390/engproc2025117009 - 3 Dec 2025

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Abstract

Microplastics, plastic particles smaller than 5 mm, are now ubiquitous and represent a form of pollution that threatens ecosystems and human health, infiltrating the environment, air, and food chain. The search for solutions to microplastics requires industrial policies that limit plastic production and [...] Read more.

Microplastics, plastic particles smaller than 5 mm, are now ubiquitous and represent a form of pollution that threatens ecosystems and human health, infiltrating the environment, air, and food chain. The search for solutions to microplastics requires industrial policies that limit plastic production and technological innovations for removal and recycling. Specifically, this paper reports a sustainable and cost-effective method for the detection of high-density polyethylene (HDPE) and low-density polyethylene (LDPE) microplastics using nitrogen-doped carbon dots (N-CD) synthesized from onion peel and L-cysteine via hydrothermal carbonization. Two precursor ratios (1:1 and 1:0.30 w/w) were evaluated. The resulting N-CDs exhibited bright yellow-green fluorescence (470–500 nm) and excitation-dependent photoluminescence under 365 nm UV light. FTIR and UV-Vis spectroscopy confirmed the presence of nitrogen-containing functional groups and effective graphitization, particularly in the 1:0.30 ratio. Fluorescence imaging revealed stronger intensity and greater stain uniformity in thermally softened MPs treated with 1:0.30 N-CDs, with a peak emission of 10,230.02 a.u. at 2 h and PMT 11—surpassing the 1:1 ratio. Bandgap and absorbance analyses supported the superior optical behavior of the lower-concentration formulation. Image analysis further indicated increased luminescent area over time, and two-way ANOVA confirmed statistically significant effects of heating time and PMT settings (p < 0.05). Compared to traditional filtration staining, thermal-assisted application offered enhanced and stable fluorescence. These findings demonstrate the efficacy of green-synthesized N-CDs for MP detection, with potential scalability and environmental applicability. Future work should explore alternative biomass sources and assess N-CD performance under field conditions to optimize environmental sensing strategies. Full article

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9 pages, 286 KB

Open AccessProceeding Paper

Synthesis of 2-Naphthyl 2-Chloroacetate and Study of Its Nucleophilic Substitution Reactions with Citric Acid

by Ruzimurod Jurayev, Azimjon Choriev, Anvar Abdushukurov and Ilyos Normurodov

Eng. Proc. 2025, 117(1), 10; https://doi.org/10.3390/engproc2025117010 - 8 Dec 2025

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Abstract

In this study, an efficient and regioselective synthetic method was developed for the preparation of 3-hydroxy-3-((2-(naphthalen-2-yloxy)-2-oxoethoxy)carbonyl)pentanedioic acid, a multifunctional ether–ester compound of potential interest for pharmaceutical and material science applications. The target compound was synthesized via the nucleophilic substitution (SN2) and esterification reactions [...] Read more.

In this study, an efficient and regioselective synthetic method was developed for the preparation of 3-hydroxy-3-((2-(naphthalen-2-yloxy)-2-oxoethoxy)carbonyl)pentanedioic acid, a multifunctional ether–ester compound of potential interest for pharmaceutical and material science applications. The target compound was synthesized via the nucleophilic substitution (SN2) and esterification reactions of 2-naphthyl chloroacetate with the monosodium salt of citric acid. Optimization of the reaction conditions was carried out by varying the molar ratio of the reagents, reaction temperature, and duration. The highest yield of 83% was achieved under the conditions of a 2:1 molar ratio of chloroacetate to citrate, a temperature of 70–80 °C, and a reaction time of 6 h. The enhanced product yield observed under these conditions is attributed to the dual reactivity of the citric acid monosodium salt, which contains a free hydroxyl group capable of undergoing SN2 etherification, and free carboxylic acid groups that participate in esterification with the electrophilic 2-naphthyl chloroacetate. The stoichiometric 2:1 ratio ensures that both reactive centers on the citrate anion are fully utilized, leading to efficient and selective transformation into the desired product. Mechanistically, the ether bond formation proceeds through the classical Williamson ether synthesis pathway, where the alkoxide formed from the hydroxyl group attacks the electrophilic carbon of the chloroacetate, displacing the chloride ion. Concurrently, esterification enhances molecular complexity and stability. The results underline the synthetic utility of citric acid derivatives in forming complex organic architectures via environmentally benign routes. This study not only contributes a practical approach to multifunctional molecule synthesis but also reinforces the applicability of green chemistry principles in ester–ether coupling strategies. Full article

7 pages, 872 KB

Open AccessProceeding Paper

Application of Reduced Graphene Oxide in Biocompatible Composite for Improving Its Specific Electrical Conductivity

by Mikhail Savelyev, Artem Kuksin, Ekaterina Otsupko, Victoria Suchkova, Kristina Popovich, Pavel Vasilevsky, Ulyana Kurilova, Sergey Selishchev and Alexander Gerasimenko

Eng. Proc. 2025, 117(1), 11; https://doi.org/10.3390/engproc2025117011 - 8 Dec 2025

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Abstract

The reduced graphene oxide (rGO) combination in association with the single-walled carbon nanotubes (SWCNTs) in a dispersion minimizes the number of carbon particles to obtain a hydrogel with the same level of specific conductivity. When developing neuroimplants intended to restore damaged neural networks [...] Read more.

The reduced graphene oxide (rGO) combination in association with the single-walled carbon nanotubes (SWCNTs) in a dispersion minimizes the number of carbon particles to obtain a hydrogel with the same level of specific conductivity. When developing neuroimplants intended to restore damaged neural networks or modulate pain transmission, biocompatibility and the permeability of stimulating currents are key requirements. The specific conductivity of the resulting hydrogels with the addition of different carbon nanoparticles was 19 mS/cm (1-SWCNTs), 17 mS/cm (2-rGO), and 35 mS/cm (3-SWCNTs/rGO). The results confirm the possibility of regulating the degradation time. Colorimetric assay for assessing cell metabolic activity (MTT) assay using the Neuro 2A cell line showed sufficient biocompatibility for the amount of SWCNTs and rGO used. Full article

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8 pages, 1306 KB

Open AccessProceeding Paper

Prediction and Optimisation of Cr (VI) Removal by Modified Cellulose Nanocrystals from Aqueous Solution Using Machine Learning (ANN and ANFIS)

by Banza Jean Claude, Vhahangwele Masindi and Linda L. Sibali

Eng. Proc. 2025, 117(1), 12; https://doi.org/10.3390/engproc2025117012 - 9 Dec 2025

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Abstract

Cellulose nanocrystals (CNCs) have emerged as highly efficient adsorbents for heavy metal removal owing to their biodegradability, wide availability, and rich surface chemistry. Their abundant hydroxyl and other reactive functional groups provide a high density of active sites, significantly enhancing their affinity and [...] Read more.

Cellulose nanocrystals (CNCs) have emerged as highly efficient adsorbents for heavy metal removal owing to their biodegradability, wide availability, and rich surface chemistry. Their abundant hydroxyl and other reactive functional groups provide a high density of active sites, significantly enhancing their affinity and adsorption capacity for toxic metal ions such as chromium (VI). The green adsorbent was characterised using FTIR to identify the functional groups. The optimum conditions were pH 6, concentration 140 mg/L, time 120 min, and adsorbent dosage 6 g/L, with a percentage removal of 95%. Deep machine learning was employed to predict the removal capacity of green and biodegradable adsorbents for chromium (VI) removal from wastewater. The findings show that adaptive neuro-fuzzy inference systems effectively model the prediction of Chromium (VI) adsorption. The Levenberg–Marquardt algorithm (LM) was used to train the network through feedforward propagation. In the training dataset, R² was 0.966, Mean Square Error (MSE) 0.042, Absolute average relative error (AARE) 0.053, Root means square error (RMSE) 0.077, and average relative error (ARE) 0.053 for the artificial neural network. The RMSE of 0.021, AARE of 0.015, ARE of 0.01, MSE of 0.017, and R² of 0.998 for the adaptive neuro-fuzzy inference system. These findings confirm the strong adsorption potential of CNCs and the suitability of advanced machine learning models for forecasting heavy metal removal efficiency. Full article

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9 pages, 971 KB

Open AccessProceeding Paper

Parametric Study of Slow Pyrolysis on Invasive Water Hyacinth for Energy Recovery and Towards Cleaner Blue Carbon Technologies

by Pauline Patrice Tamoria, Eugenie Mhel Chavez, Trisha Camille Garcia, Winnieruth Manio, Ivy Jane Milana, Rugi Vicente Rubi, Eric Halabaso and Rich Jhon Paul Latiza

Eng. Proc. 2025, 117(1), 13; https://doi.org/10.3390/engproc2025117013 - 10 Dec 2025

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Abstract

The urgent need for cleaner energy sources has driven exploration into innovative and sustainable solutions. This study investigates the potential of the invasive aquatic plant, the water hyacinth, to contribute to energy recovery and support the preservation of blue carbon ecosystems through biomass [...] Read more.

The urgent need for cleaner energy sources has driven exploration into innovative and sustainable solutions. This study investigates the potential of the invasive aquatic plant, the water hyacinth, to contribute to energy recovery and support the preservation of blue carbon ecosystems through biomass removal. Employing slow pyrolysis, this study examines the influence of temperature (300–500 °C) and residence time (30–90 min) on bio-oil and biochar production in a fixed-bed reactor. Results revealed that residence time was the key operational parameter significantly influencing total liquid condensate yield, which peaked at 34.34 wt% at 400 °C after 90 min. Moisture content reveals an actual organic bio-oil yield of approximately 3.4–4.8 wt%. In contrast, biochar yield (max. 43.74 wt%) was not significantly affected by the tested parameters. The resulting bio-oil exhibited a high heating value of up to 25.84 MJ/kg, suggesting its potential as a renewable fuel. This study concludes that slow pyrolysis of invasive water hyacinth provides a dual-benefit pathway: it co-produces renewable bio-oil for energy recovery alongside a stable biochar, offering a tangible route for blue carbon sequestration. This integrated approach transforms an environmental liability into valuable resources, contributing to a cleaner environment and a more sustainable future. Full article

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8 pages, 1520 KB

Open AccessProceeding Paper

Robust Control Design for an Off-Board EV Charger Considering Grid Impedance Variation

by Chhaytep Born, Menghorng Sy, Panha Soth, Heng Tang, Socheat Yay, Seven Siren, Channareth Srun and Chivon Choeung

Eng. Proc. 2025, 117(1), 14; https://doi.org/10.3390/engproc2025117014 - 12 Dec 2025

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Abstract

Grid impedance variation has the possibility of leading to voltage oscillation and control instability, which poses a serious problem to electric vehicle (EV) charger design. In response to this problem, this paper proposes a robust control approach that is capable of dealing with [...] Read more.

Grid impedance variation has the possibility of leading to voltage oscillation and control instability, which poses a serious problem to electric vehicle (EV) charger design. In response to this problem, this paper proposes a robust control approach that is capable of dealing with grid impedance variation and system uncertainties. The proposed dual-loop control strategy is composed of an outer-loop proportional–integral (PI) controller and an inner-loop robust state feedback controller with integral action. The benefits of control are maximized according to linear matrix inequality (LMI) techniques. This paper aims to address the effects of grid impedance variation by including the uncertainty model considering the potential varying parameters in the control design process. Additionally, the uncertainty model considers sixteen possible sets, which are described by variations in the four most important parameters: grid impedance, grid resistance, filter impedance, and filter resistance. The simulations suggest that the proposed controller maintains stable current regulation for uncertainty factors as high as γ = 3.3, where all closed-loop poles remain within the unit circle. For all the tested uncertainty levels, the grid-current tracks the reference of 10 A with a faster settling time at γ = 1.1 and no overshoot for higher uncertainty levels. Full article

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18 pages, 2500 KB

Open AccessProceeding Paper

Interface Engineering in Hybrid Energy Systems: A Case Study of Enhance the Efficiency of PEM Fuel Cell and Gas Turbine Integration

by Abdullatif Musa, Gadri Al-Glale and Magdi Hassn Mussa

Eng. Proc. 2025, 117(1), 15; https://doi.org/10.3390/engproc2025117015 - 18 Dec 2025

Viewed by 548

Abstract

Integrating electrochemical fuel cells and internal combustion engines can enhance the total efficiency and sustainability of power systems. This study presents a promising solution by integrating a Proton Exchange Membrane Fuel Cell (PEMFC) with a mini gas turbine, forming a hybrid system called [...] Read more.

Integrating electrochemical fuel cells and internal combustion engines can enhance the total efficiency and sustainability of power systems. This study presents a promising solution by integrating a Proton Exchange Membrane Fuel Cell (PEMFC) with a mini gas turbine, forming a hybrid system called the “Oya System.” This approach aims to mitigate the efficiency losses of gas turbines during high ambient temperatures. The hybrid model was designed using Aspen Plus for modelling and the EES simulation program for solving mathematical equations. The primary objective of this research is to enhance the efficiency of gas turbine systems, particularly under elevated ambient temperatures. The results demonstrate a notable increase in efficiency, rising from 37.97% to 43.06% at 10 °C (winter) and from 31.98% to 40.33% at 40 °C (summer). This improvement, ranging from 5.09% in winter to 8.35% in summer, represents a significant achievement aligned with the goals of the Oya System. Furthermore, integrating PEMFC contributes to environmental sustainability by utilising hydrogen, a clean energy source, and reducing greenhouse gas emissions. The system also enhances efficiency through waste heat recovery, further optimising performance and reducing energy losses. This research highlights the critical role of interface engineering in the hybrid system, particularly the interaction between the PEMFC and the gas turbine. Integrating these two systems involves complex interfaces that facilitate the transfer of electrochemistry, energy, and materials, optimising the overall performance. This aligns with the conference session’s focus on green technologies and resource efficiency. The Oya System exemplifies how innovative hybrid systems can enhance performance while promoting environmentally friendly processes. Full article

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9 pages, 1298 KB

Open AccessProceeding Paper

A Novel Circular Waste-to-Energy Pathway via Cascading Valorization of Spent Coffee Grounds Through Non-Catalytic Supercritical Transesterification of Pyrolytic Oil for Liquid Hydrocarbon

by Elmer Jann Bantilan, Joana Batistil, Bernice Ann Calcabin, Ephriem Organo, Neome Mitzi Ramirez, Jayson Binay, Reibelle Raguindin, Rugi Vicente Rubi and Rich Jhon Paul Latiza

Eng. Proc. 2025, 117(1), 16; https://doi.org/10.3390/engproc2025117016 - 4 Jan 2026

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Abstract

The ever-growing global consumption of coffee generates millions of tons of spent coffee grounds (SCG) annually, posing a significant waste disposal problem. Although some SCG find use in composting or biogas production, a large portion remains underutilized. This study introduces a novel circular [...] Read more.

The ever-growing global consumption of coffee generates millions of tons of spent coffee grounds (SCG) annually, posing a significant waste disposal problem. Although some SCG find use in composting or biogas production, a large portion remains underutilized. This study introduces a novel circular waste-to-energy pathway to tackle this challenge. Our proposed technology employs a cascading valorization approach, utilizing non-catalytic supercritical transesterification of pyrolytic oil derived from SCG for liquid hydrocarbon production. The process begins with pyrolysis, which converts SCG into pyrolytic oil. This oil is then upgraded via supercritical transesterification with methanol. Experiments were conducted using a 1:6 oil-to-methanol ratio at precisely controlled conditions of 239.4 °C and 1200 psi for 20 min. This optimized process yielded an impressive 96% of valuable liquid hydrocarbon product. The resulting product exhibited highly favorable characteristics, including a density of 755.7 kg/m³, a viscosity of 0.7297 mm²/s, and a high heating value (HHV) of 48.86 MJ/kg. These properties are remarkably comparable to conventional biofuels and standard fossil fuels, demonstrating the product’s potential as a viable energy source. Full article

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10 pages, 1994 KB

Open AccessProceeding Paper

A Leptolyngbya-Dominated Consortium for the Optimized Biological Treatment of Mixed Agro-Industrial Effluents

by Vasiliki Patrinou, Dimitris V. Vayenas and Athanasia G. Tekerlekopoulou

Eng. Proc. 2025, 117(1), 17; https://doi.org/10.3390/engproc2025117017 - 7 Jan 2026

Abstract

Many individual wastewater streams exhibit imbalanced or poor nutrient profiles, limiting their suitability for efficient biological treatment. In regions where several agro-industrial activities coexist, these streams are often produced in small volumes and vary considerably in composition, making their combined use an effective [...] Read more.

Many individual wastewater streams exhibit imbalanced or poor nutrient profiles, limiting their suitability for efficient biological treatment. In regions where several agro-industrial activities coexist, these streams are often produced in small volumes and vary considerably in composition, making their combined use an effective way to obtain a more balanced influent. This study aimed to identify the optimal mixing ratio of two agro-industrial wastewaters, second cheese whey (SCW) and poultry wastewater (PW), for the cultivation of a Leptolyngbya-dominated consortium. Four mixing ratios of SCW:PW (50:50%, 60:40%, 70:30%, and 85:15%) were examined based on an initial dissolved chemical oxygen demand (d-COD) concentration of 3000 mg L⁻¹. The 70:30% ratio was led to significant biomass production (268.3 mg L⁻¹ d⁻¹), while simultaneously exhibiting the highest lipid content (14.0% d.w.), and the highest removal of d-COD (89.2%), total nitrogen (64%) and PO₄³⁻-P (60%). Overall, the experiments showed that using nutritionally balanced wastewater streams is a promising strategy to enhance biological treatment efficiency and lipid production. Full article

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Eng. Proc., 2025, ECP 2025

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