Additive manufacturing, particularly 3D printing, is increasingly shaping the production of polymer-based components, enabling complex geometries and tailored functional performance. Yet, predicting their mechanical behavior remains challenging due to material anisotropy and sensitivity to processing conditions. This work presents an exploratory study designed to provide the experimental basis for the development and calibration of predictive models of mechanical properties in 3D-printed components.

Standard ISO 527-2 Type 1A specimens were fabricated using two thermoplastics, PLA (polylactic acid) and ABS (acrylonitrile butadiene styrene), with systematic variations in layer orientation, infill overlap, and printing velocity. Mechanical characterization was carried out through uniaxial tensile testing to determine tensile strength and elastic modulus of the material specimens, while scanning electron microscopy (SEM) provided complementary insights into interlayer bonding, filament alignment, porosity, and fracture morphology.

Results showed that both material type and processing strategies strongly influenced mechanical response, with SEM highlighting microstructural features that govern interlayer adhesion and failure mechanisms. These findings contribute to a deeper understanding of process–structure–property relationships in additive manufacturing and establish the groundwork for predictive model development. Ongoing efforts will integrate these experimental insights into numerical simulations employing anisotropic and homogenized material models, thereby enhancing design optimization and reliability of 3D-printed structural components

Air pollution is one of the major global concerns impacting the pillars of sustainability—economic, environmental, and social factors. In the Philippines, air pollution continues to deteriorate due to multiple factors, as reflected in the exceeding threshold value of the country’s air quality parameters set by the World Health Organization (WHO). With the rapid urbanization of the country, research shows that building morphology affects the air flow in urban and rural areas, contributing to air pollution concentration.

This study aims to compare and analyze the concentrations of the key pollutants—PM_2.5, CO, NO₂, and SO₂—from the open dataset of Copernicus Sentinel-5P Precursor in association with the building morphology and meteorological factors of urban and suburban areas over the past five years. Moreover, two analytical methods were conducted: (1) a multivariate time-series analysis was performed to examine the trend of air pollutants in correlation with meteorological factors and urban morphology in these areas, and (2) a comparative analysis was performed to assess the similarities and differences of pollution concentrations across geographical areas. The results indicate that the concentration of the key pollutants is slightly higher in the urban areas than in the suburban areas. This pattern may be attributed to the morphology of geographical areas with low-rise and medium-rise buildings, which predominate in suburban areas, indicating a better air flow in these areas. These findings formulate recommendations that will benefit geographical areas in targeted air quality mitigation.

The semi-arid nation of South Africa deals with critical water shortages and deteriorating water quality because of rising population numbers as well as expanding urban areas and industrial operations. The protection of water resources depends heavily on wastewater treatment, yet treated wastewater continues to serve as a significant pollution source. The study assesses environmental effects from the Atlantis (Wesfleur) Wastewater Treatment Works (WWTW) located in the Western Cape while studying its pollution impact on the Donkergat River. The research team obtained water samples from the treatment plant effluent and river water downstream between October and November 2023 to measure COD, TSS, nitrates, orthophosphates, chloride, conductivity, sulphates, and pH levels. The Atlantis WWTW effluent met all requirements set by the Department of Water and Sanitation (DWS) and South African National Standards (SANS 241-1:2015). The COD, TSS, and nutrient measurements in the treated water stayed within the established limits. The river water quality showed high chloride (264 mg/L) and sulphate (1543 mg/L) levels during multiple sampling events because of wastewater discharge accumulation and suspected human-made pollution sources. The WWTW achieves satisfactory treatment performance, but the research demonstrates that ongoing surveillance, facility enhancements, and environmental protection strategies are essential to protect water bodies. The results support the ongoing discussion about achieving proper wastewater treatment and environmental protection in areas with limited water resources.

Cooking oil waste is a common by-product from households, restaurants, and food industries, and its improper disposal can cause severe environmental pollution. Repeated use of cooking oil leads to chemical degradation through oxidation, hydrolysis, and polymerization, resulting in darkening, off-odors, elevated free fatty acids (FFAs), and increased peroxide values, posing potential health and environmental risks. This study aimed to investigate the purification efficiency of coconut shell-derived activated carbon in reducing free fatty acid contents and improving oil quality parameters, including pH, calorific value, viscosity, and density. Activated carbon was produced by carbonizing coconut shells at 450 °C for 3 hours under limited oxygen using a lab-scale pyrolysis reactor. The resulting charcoal was then chemically activated with KOH, washed to a neutral pH, dried, and ground to ≤250 µm. Adsorption experiments were performed by adding 2.5% (w/w) activated carbon to 450 ml of cooking oil waste and stirring at 600 rpm for contact times of 30, 60, and 90 minutes. The treated oil was filtered using Whatman No. 1 filter paper (110mm diameter) and analyzed for FFA, pH, calorific value, viscosity, and density. Our results showed that the FFA content decreased significantly from 0.286% to 0.049% (82.9% reduction) with increasing contact time, while the pH improved from 4.62 to 5.91, indicating effective removal of acidic degradation products. The calorific value increased slightly from 8981 to 9019 Cal/g, suggesting removal of oxidized and polar compounds. The purified waste cooking oil, with reduced acidity and improved pH, is suitable for biodiesel production and non-food industrial applications, demonstrating potential for circular economy implementation.

This study extends previous investigations on the thermal performance of slab-on-ground foundations by applying dynamic numerical simulations to analyse ground temperature distribution. In contrast to earlier research based on steady-state conditions, the present work incorporates transient boundary conditions that capture both seasonal and diurnal climatic variations. Such an approach allows for a more comprehensive representation of heat transfer processes between the foundation, insulation and surrounding soil. The research focuses on a parametric study of edge insulation configurations, considering variations in thickness, depth and horizontal extension. The analysis aims to assess how different design strategies influence the thermal regime of the soil adjacent to the foundation edge, with particular regard to frost protection and long-term durability. By addressing the time-dependent nature of ground temperature changes, this study seeks to provide a methodological framework for evaluating insulation performance under realistic environmental conditions. The novelty of the approach lies in highlighting the limitations of simplified steady-state calculations and exploring the advantages of dynamic modelling in foundation engineering. The outcomes are expected to support designers and engineers in optimising edge insulation systems, improving the accuracy of building energy models, enhancing the resilience of structures to climate variability, and supporting energy-efficient and resilient building practices in cold and temperate climates.

The growing demand for renewable energy and resource-efficient waste management has intensified interest in alternative lignocellulosic feedstocks. This study investigates the thermal decomposition behavior and proximate composition of eight cultivars of Camellia japonica flowers, a widely cultivated but underutilized ornamental species. Thermogravimetric analysis was employed to assess weight loss dynamics under controlled heating, while derivative thermogravimetry and heat flow data provided further insights into decomposition stages and energy release patterns. All samples exhibited a characteristic three-step degradation: (i) initial moisture loss below 120 °C, (ii) an active devolatilization stage between 200 and 400 °C associated with hemicellulose and cellulose breakdown, and (iii) a final slow degradation phase above 450 °C, typically attributed to lignin decomposition and char formation. Among the cultivars studied, Carolyn Tuttle and Conde de la Torre showed the highest volatile matter contents (97.34- 97.26%), indicating strong potential for pyrolysis-based valorization. Conversely, Elegans Variegated exhibited the highest apparent fixed carbon retention (−0.15%), with a slightly lower volatile fraction (96.59%). Ash content was consistently low. The average volatile matter content across all samples exceeded 96%, confirming the high organic fraction that is typical of floral biomass. Fixed carbon values remained within a narrow range (−0.01% to −0.15%), suggesting minimal residual char formation and indicating suitability for fast pyrolysis or combustion with limited solid waste output. These findings highlight Camellia japonica flowers as a promising biomass resource with favorable thermochemical properties. Their high volatility, low ash contents, and consistent thermal profiles support their inclusion in circular bioeconomy models and localized bioenergy strategies, particularly in regions with substantial ornamental plant waste.

Life Cycle Assessments (LCAs) have emerged as essential tools for identifying critical environmental aspects across the life cycle of products, processes, or services, thereby helping to reduce associated environmental impacts, compare alternative scenarios and implement strategies for enhanced sustainability. This methodology has been applied to Living Wall Systems (LWSs), which are conceived as sustainable systems designed to improve environmental conditions in the built environment. However, context-specific analyses are required for tropical countries, as well as system designs that can more effectively account for their entire life cycle. The aim of this study is to evaluate the Global Warming category of a LWS in the city of Medellín through life cycle modeling using SimaPro software (version 10.1.0.6). For the environmental inventory, the Ecoinvent® v3.10 database was employed, covering materials, energy, transportation, and end-of-life processes, with a focus on the Global Warming Potential (GWP) impact category. The results show a total of 39.11 kg CO₂ eq for the entire system. Of this, the Construction stage accounted for 34.67 kg CO₂ eq, representing 89% of the total (GWP) impact category. This highlights the need for special attention during this stage, particularly regarding the polyethylene pipe for the irrigation system (21.79 kg CO₂ eq) and the reinforcing steel used in the support structure (11.84 kg CO₂ eq).

Mercury contamination of soils, even at relatively low levels, remains a global environmental and health concern due to its persistence, bioaccumulation, and toxicity. Phytoremediation offers a sustainable and cost-effective strategy, and the addition of organic amendments can improve plant growth and metal uptake. This study investigated the use of chicken manure compost to enhance mercury removal by Brachiaria dyctioneura, a tropical forage species with high adaptability and biomass production. Two soils with initial mercury concentrations of 106.07 ± 13.41 μg/kg and 672.234 ± 74.59 μg/kg were amended with chicken manure at 1:4 and 3:4 ratios (manure:soil). Physicochemical properties, organic carbon, nitrogen, phosphorus, and metal contents were characterized. Seeds of B. dyctioneura (1 g per experimental unit) were sown with five replicates per treatment. After 30 days, plants were separated into roots and shoots for mercury determination using EPA Method 7473 with a RA-915LAB Direct Mercury Analyzer. Results indicated that lower amendment levels enhanced mercury accumulation in shoots, favoring aerial translocation, while higher doses increased retention in roots and reduced translocation. For Soil 1, mercury concentrations were 3.49–24.92 μg/kg in roots and 10.32–14.63 μg/kg in shoots, whereas in Soil 2 values reached 13.44–191.53 μg/kg in roots and 67.59–90.47 μg/kg in shoots. These results suggest that amendment dosage significantly influences mercury partitioning in plants. The findings highlight the potential of B. dyctioneura as a promising species for mercury phytoremediation, with chicken manure compost serving as an effective amendment to optimize remediation performance.

Title:
Engineered Nanostructured Surfaces for Dual Antibacterial and Cell-Guiding Applications in Biomedical Devices

The rise of antibiotic-resistant pathogens, including Escherichia coli, presents a pressing global health concern, demanding innovative, non-chemical strategies to combat microbial infections. Among these, nanostructured surfaces inspired by natural bactericidal topographies offer a promising route. In this work, we present a robust approach to fabricate highly controlled nanopatterns—specifically nanogratings and nanopillar arrays—on poly(methyl methacrylate) (PMMA) substrates using Electron Beam Lithography, with pitch sizes varying from 160 to 210 nm.

Following detailed surface characterization, the interaction between these engineered nanotopographies and E. coli was assessed, focusing on bacterial adhesion, viability, and mechanical integrity. Advanced imaging techniques including Atomic Force Microscopy (AFM), Ultra High-Resolution Scanning Electron Microscopy (UHR-SEM), and Focused Ion Beam (FIB) milling enabled the observation of nanoscale morphological changes and structural damage to bacterial membranes, shedding light on the physical mechanisms behind their antibacterial activity.

Beyond antimicrobial functionality, these nanostructured surfaces were evaluated for their compatibility with human cells to explore their potential for biomedical applications. Cell adhesion, proliferation, and alignment were studied to determine cellular responses to the topographic features. The results confirm the feasibility of using a single platform to investigate and modulate both bacterial inhibition and guided cell behavior.

This study highlights a multifunctional surface engineering strategy that integrates bactericidal performance with cell-instructive capabilities, paving the way for next-generation implantable devices with enhanced infection resistance and improved tissue integration.

Cyanide contamination from mining and industrial activities represents a severe environmental hazard due to its acute toxicity and persistence in aquatic ecosystems. Effective removal technologies are urgently required to safeguard water resources and ecological health. This study addresses this challenge by evaluating the scale-up of a TiO₂-based rotary concentrator photoreactor (RCPR) specifically engineered for the photocatalytic degradation of cyanide in contaminated water. Building on a previously developed pilot-scale reactor, the system was assessed through integrated modeling and simulation approaches to enhance design efficiency. The methodology combined geometric sizing, a one-dimensional thermal energy balance, and optical simulations conducted in SolTRACE 3.0, under site-specific environmental conditions from the Colombian Caribbean. Results demonstrated that geometric configuration, optical concentration, and material selection exerted a strong influence on reactor performance. Cyanide removal efficiency was confirmed experimentally and validated by acute toxicity bioassays using Daphnia magna, which provided ecotoxicological evidence of treatment effectiveness. Degradation kinetics closely matched mathematical predictions, underscoring the robustness of the model. In addition, scenario analyses explored alternative reactor geometries and construction materials to support real-scale deployment. Environmental efficiency indicators and cost–benefit analyses further highlighted the feasibility of this technology for mining wastewater treatment. These findings deliver technical, ecological, and economic insights that advance photocatalytic processes toward sustainable and scalable water treatment solutions.