Search Results (877)

This study investigates the sustainable reuse of industrial enamel frit production waste generated during enamel application processes and evaluates its potential from a process-oriented glass-forming and -shaping perspective. Enamel frit waste collected from an industrial production line in Türkiye was subjected to comprehensive characterization, including XRD, XRF, TG/DTA, dilatometry, and CIE Lab* color analysis, with the primary aim of assessing forming compatibility rather than final product performance. Following calcination and controlled fritting, the waste material was processed through mold-based glass-forming experiments using firing schedules derived from thermal analysis. The results reveal pronounced chemical and thermal heterogeneity among enamel frit production wastes, leading to variable melting behavior across samples. Nevertheless, selected waste compositions exhibited sufficient viscous flow for shaping at reduced firing temperatures of approximately 850 °C. This study demonstrates that selected enamel frit production wastes—obtained from industrial enameling processes in slurry, powder, or granular form—can be reshaped into glass forms under controlled low-temperature conditions. The novelty of this study lies in investigating industrial enamel production frit waste as a reusable material within a circular economy framework, specifically focusing on its application in mold-based glass forming for artistic and educational contexts, thereby fostering collaboration between industrial waste management and glass art practice. Full article

Glass wool waste constitutes a rapidly increasing fraction of construction and demolition residues, yet it remains one of the most challenging insulation materials to recycle. Its non-combustible nature, extremely low bulk density, and high fibre elasticity preclude energy recovery and severely limit conventional mechanical recycling routes, resulting in long-term landfilling and loss of mineral resources. Converting glass wool waste into a fine mineral powder represents a potentially viable pathway for its integration into low-carbon construction materials, provided that industrial scalability, particle-size control, and chemical compatibility with cementitious binders are ensured. This study investigates the industrial-scale milling of end-of-life glass wool waste in a ventilated horizontal ball mill. It compares two grinding routes: a corundum-free route (BK) and an abrasive-assisted route (ZK) employing α-Al₂O₃ corundum to intensify fibre fragmentation. Particle size distribution was quantified by laser diffraction using cumulative and differential analyses, as well as characteristic diameters. The results confirm that abrasive-assisted milling significantly enhances fragmentation efficiency and reduces the coarse fibre fraction. However, the study demonstrates that this gain in fineness is inherently coupled with the incorporation of α-Al₂O₃ into the milled powder, introducing a chemically foreign crystalline phase that cannot be removed by post-processing. From a cement-oriented perspective, this contamination represents a critical limitation, as α-Al₂O₃ may interfere with hydration reactions, aluminate–sulfate equilibria, and microstructural development in Portland and calcium sulfoaluminate binders. In contrast, the corundum-free milling route yields a slightly coarser, chemically unmodified powder, offering improved process robustness, lower operational complexity, and greater compatibility with circular economy objectives. The study establishes that, for the circular reuse of fibrous insulation waste in cementitious systems, particle fineness alone is insufficient as an optimization criterion. Instead, the combined consideration of fineness, chemical purity, and binder compatibility governs the realistic and sustainable reuse potential of recycled glass wool powders. Full article

The structural origin of the germanate anomaly in glasses, which involves complex Ge–O coordination environments, is frequently studied using crystalline analogs. This study aims to provide reliable spectroscopic fingerprints by performing a detailed structural and thermal analysis of crystalline A₄Ge₉O₂₀ model systems with A = Li, Na, K. The compounds were synthesized via melt crystallization and characterized using powder X-ray diffraction (PXRD), differential scanning calorimetry (DSC), and Raman spectroscopy techniques. The results demonstrate clear cation-dependent crystallization pathways. The Li-containing system predominantly forms Li₂Ge₇O₁₅ in mixture with Li₄Ge₉O₂₀, indicating a preference for thermodynamically stable phases. The Na-system successfully yields the target Na₄Ge₉O₂₀ compound. In contrast, the K-system primarily produces the likely metastable K₂Ge₄O₉ phase with a significant amorphous fraction, highlighting the role of kinetic limitations. This comparative study demonstrates that the size of the alkali cation is a critical factor for controlling phase formation under identical stoichiometric and thermal conditions. Full article

Under impact loading, the performance of ordinary waste glass powder concrete is lower than that of ordinary concrete. To enhance the impact resistance of waste glass powder concrete, renewable polyvinyl alcohol (PVA) fibers are introduced. Considering the effects of PVA fiber volume content (0.4%, 0.8%, 1.2%) and fiber length (6 mm, 12 mm, 18 mm), the basic mechanical properties and impact resistance of PVA-fiber-reinforced waste glass powder concrete are investigated through compression tests, flexural tests, and drop hammer impact tests. The results show that the incorporation of PVA fibers can effectively improve the impact resistance of waste glass powder concrete, and both the compressive and flexural strength are enhanced to varying degrees. The experimental results show that when the fiber volume content is 0.8% and the length is 12 mm, the flexural strength of the sample is the best. In addition, the impact of fiber length on performance varies by index; shorter fibers (6 mm) perform more prominently in enhancing impact toughness, while longer fibers (12 mm) are more conducive to the growth of flexural strength. There is a positive correlation between the impact resistance of the specimens and the fiber content; as the content of PVA fibers increases, both the initial crack impact number and the failure impact number show an increasing trend, and the energy absorbed by the concrete during initial cracking and failure gradually increases. The highest impact energy dissipation is achieved with the incorporation of 1.2% 6 mm fibers. Based on the experimental results, a functional relationship between fiber length, fiber content, and impact energy absorption is proposed for PVA-fiber-reinforced waste glass powder concrete. Full article

In recent years, new methods to reuse, repurpose, recycle, and recover decommissioned wind turbine blades (dWTBs) have actively been developed in the wind industry. In this study, the authors address the scientific challenge of repurposing decommissioned wind turbine blades for earthwork applications, particularly as part of retaining structures. A gravity retaining structure made entirely from recycled materials is introduced, consisting of glass fibre-reinforced polymer (GFRP) composite modular units derived from dWTBs. To improve the structure’s sustainability, a mixture of typical sand and lightweight waste materials is considered for filling and backfilling of the GFRP units. In particular, two waste materials are examined—a polymer foil derived from recycled laminated glass and tyre-derived aggregate (TDA) in the form of rubber powder—which are incorporated into the sand matrix in typical dry mass proportions ranging from 2% to 32% and 5% to 20%, respectively, reflecting practical ranges considered in geotechnical backfill applications. The research involved material testing of all recyclates and their mixtures with standard sand, as well as two-dimensional finite-element (2D FE) analysis of a retaining structure using the determined material properties. To facilitate the real-world implementation of this novel technology, a structure was designed to account for ground conditions at a specific site to protect against an existing landslide. In summary, this study presents the concept of a sustainable retaining structure along with results from material tests and an initial design for implementation, supported by FE analysis of overall stability. Full article

This study investigates the valorisation of mixed municipal waste glass (MMWG; EWC 20 01 02) as a sustainable supplementary material in cement mortars. In contrast to most existing studies, which focus almost exclusively on homogeneous container glass, this work addresses a heterogeneous waste stream derived from municipal selective collection, containing flat glass, mirrors, ceramics, porcelain, and metallic residues. Such mixed household glass has not previously been systematically evaluated in cement mortars, thereby addressing a clear research gap. The MMWG was washed, dried, and ground in a Los Angeles drum with corundum abrasives to obtain a fine glass powder (FGP < 63 µm) with a median particle size of approximately 20 µm and a Blaine fineness of 360 m²/kg. Microstructural and chemical characterisation of the milled glass confirmed its highly amorphous nature and angular particle morphology resulting from grinding. In addition, coarse glass granules (0–4 mm) were used as partial replacements for natural sand in mortar mixtures. The incorporation of FGP led to a 4–12% reduction in flowability, attributable to the angular shape and increased specific surface area of the ground-glass particles. At 28 days, mortars containing 5–10% FGP exhibited mechanical properties comparable to the reference mix, while at 56 days their compressive strength increased by up to 8%, indicating delayed pozzolanic activity typical of finely milled, amorphous glass. Mortars containing coarse glass primarily reflected a filler and aggregate-replacement effect. Leaching tests conducted in accordance with PN-EN 12457-4 demonstrated that all mortars, both reference and MMWG-modified, complied with the non-hazardous waste limits defined in Council Decision 2003/33/EC. Minor exceedances of Ba and Cr relative to inert-waste thresholds were observed; however, these values remained within the permissible range for non-hazardous classification and were attributed to ceramic and metallic contaminants inherently present in the mixed glass fraction. Overall, this study demonstrates that mixed municipal waste glass—a widely available yet rarely valorised heterogeneous waste stream—can be effectively utilised as a finely ground supplementary material and as a partial aggregate replacement in cement mortars, provided that particle fineness is adequately controlled and durability-related effects are monitored. The findings extend the applicability of glass waste beyond container cullet and support the development of circular-economy solutions in construction materials. Full article

The present paper reports the preparation of a nanocomposite thin film consisting of calcium itaconate and graphene oxide (GO). The composite is a black powder consisting of individual shiny prismatic crystals at varying degrees of maturity. The crystal size distribution is quite narrow: from 3.6 to 6.2 μm in length and from 0.7 to 1.1 μm in width. Thin-film-based acetone sensor made of a nanocomposite was fabricated by spin coating of calcium itaconate–GO nanoparticles on glass plates. The thin-film acetone sensor was characterized using FTIR, XRD, SEM, TEM, and the low-temperature nitrogen sorption–desorption method. The sensor response time is 7.66 ± 0.07 s (s_r = 0.92%), and the relaxation time when blowing the surface with clean air or inert gas (nitrogen, argon) is 9.26 ± 0.12 s (s_r = 1.28%). The sensing mechanism of the sensor for detecting acetone at room temperature was also is proposed based on phenomenological understanding due to the absence of direct electronic/charge-transport evidence. Full article

This work investigated the comparative performance of two fluidized bed agglomeration systems for producing instant coconut milk powder: a commercially manufactured unit and a hybrid dryer previously modified into a fluidized bed agglomerator. Three binder solutions, distilled water, xanthan gum, and xyloglucan polysaccharide, were employed to examine how equipment configuration and binder type influence key powder properties. The aim was to evaluate the effects of fluidized bed agglomerator design and binder selection on coconut milk powder characteristics, including moisture content, bulk density, solubility, and glass transition temperature. All samples, including the non-agglomerated control, exhibited moisture contents ranging from 2.1% and 2.6% (w.b.), meeting the criterion for safe long-term storage. Powders produced with hydrocolloid binders (xanthan gum and xyloglucan) possessed lower bulk densities than those agglomerated with water, reflecting the formation of more open particle structures. When identical binders were applied, the two agglomerators produced comparable solubility outcomes, although water-based agglomerates consistently dissolved the fastest. Differential scanning calorimetry indicated a substantial increase in glass transition temperature after agglomeration, confirming improved structural stability. Overall, the results demonstrate that both agglomeration systems effectively enhanced the physicochemical and functional characteristics of coconut milk powder, with only minor variations that were attributable to equipment design. Full article

To improve night-time visibility of pavement markings, a long-afterglow road-marking coating was developed using strontium aluminate as the phosphorescent component. The influences of particle size (100–400 mesh), dosage (15–35 wt%), filler type, and coating thickness (200–600 μm) on optical behavior were systematically evaluated. The optimal formulation—200-mesh strontium aluminate at 30 wt%, titanium dioxides combined with ultrafine glass powder, and a thickness of 500 μm—achieved an initial brightness of 3.08 cd/m² and maintained visible afterglow for more than 9 h. Durability tests confirmed satisfactory resistance to water, alkali, and abrasion, meeting the requirements of JTT 280-2022. Twinmotion simulations further demonstrated that when the coating brightness remains above 0.1 cd/m², it provides effective visual guidance on unlit road sections, thereby enhancing night-time driving safety. This study verifies the feasibility of using long-afterglow coatings to improve road visibility and reduce night-time accident risks. Full article

Three processes for the production of ceramics close to stoichiometric MgAl₂O₄ are benchmarked against each other. The traditional ceramic route is based on mostly crystalline starting powder, which is converted into ceramic via shaping and heat treatment (IKTS). The other two processes are based on glasses. Partial or complete crystallization without pressure (ISC) or complete crystallization with pressure (CAU) leads to (glass) ceramics. Spinel powder is mixed with various dopants (BaO, TiO₂, CaO and SrO), with the aim to reduce the grain size (IKTS). The doping results in a second, partly interfering phase, and the transmission decreases strongly due to absorption with increasing content of the added oxide. For the glass route without pressure (ISC), it is shown that a network-forming oxide (B₂O₃, TiO₂) is needed to produce the glasses. Compared to the starting glasses, the resultant glass ceramics suffer loss of transparency due to crystallization. Using the levitation furnace, it is possible to produce amorphous glass beads from MgAl₂O₄ enriched with 25 wt% SiO₂ without a container. The nanocrystalline ceramics synthesized from these glasses and the ISC glasses via the high-pressure route (CAU) are moderately transparent to translucent. Full article

Rapid urbanization and the widespread use of impervious materials have intensified the urban heat island (UHI) effect, raising surface temperatures and energy demands. Conventional concrete pavements contribute significantly due to their high thermal conductivity and low reflectivity. This study systematically investigates the development of thermally efficient concrete paver blocks using sustainable alternative fine aggregates to mitigate heat accumulation while retaining a minimum compressive strength of 35–45 MPa (recommended for medium traffic). Unlike prior isolated studies, this research offers a comprehensive comparative analysis of three sand replacements—Vermiculite powder (12.5–50%), Perlite powder (20–80%), and Crushed Glass (7.5–30%)—in M30-grade concrete. Fresh and hardened properties were evaluated through slump, density, and compressive strength tests at 7, 14, and 28 days, while infrared thermography quantified surface temperature variations under controlled heat exposure. Results showed significant thermal improvements, with optimal mixes Vermiculite 25% (VC-25), Perlite 40% (PR-40), and Crushed Glass 15% (CG-15) reducing surface temperatures by 25.1 °C, 22.2 °C, and 18.2 °C, respectively, while maintaining compressive strengths of 47.8 MPa, 38.8 MPa, and ~58 MPa. VC-25 proved superior, achieving the lowest surface temperature (26.3 °C) and 48.8% lower heat absorption than conventional concrete. The study establishes optimal replacement thresholds balancing insulation and strength, supporting SDGs 11, 12, and 13 through climate-responsive, resource-efficient construction materials. Full article

Background/Objectives: The poor aqueous solubility of curcumin (CUR) limits its pharmaceutical application. Although amorphization can enhance its solubility, the amorphous form often exhibits insufficient physical stability. Co-amorphization, particularly drug–drug co-amorphous (CAM) formation, offers a promising approach to improve solubility, stability, and therapeutic efficacy. This study aimed to prepare and evaluate two CUR-based CAM systems using isoquinoline alkaloids berberine hydrochloride (BER) and palmatine hydrochloride (PAL) as co-formers to achieve simultaneous stabilization and synergistic bioactivity. Methods: CUR-BER and CUR-PAL CAM systems were prepared via rotary evaporation under vacuum at a 1:1 molar ratio. The solid-state properties were characterized by powder X-ray diffraction (PXRD), differential scanning calorimetry (DSC), scanning electron microscope (SEM), and ¹³C solid-state nuclear magnetic resonance spectroscopy (ssNMR). Dissolution, solubility, and stability studies were conducted, while antioxidant and anticancer activities were assessed by DPPH/ABTS⁺ radical-scavenging and MTT assays using HT-29 colorectal cancer cells. Results: PXRD and DSC confirmed the formation of single-phase amorphous systems with higher glass transition temperatures, indicating strong intermolecular interactions between CUR and BER/PAL. ¹³C ssNMR spectroscopy evidenced hydrogen-bond formation between the enolic hydroxyl moiety of CUR and the methoxy oxygen atoms in BER or PAL molecules. Both CAM systems significantly enhanced the solubility and dissolution rate of CUR, with CUR-PAL CAM showing up to a 15.1-fold solubility improvement. The CAM systems also displayed superior thermal stability, photolytic stability, and improved short-term humidity resistance, together with enhanced antioxidant and anticancer activities compared with pure amorphous CUR. Conclusions: Co-amorphization of CUR with isoquinoline alkaloids effectively improved solubility, stability, antioxidant and anticancer activities, representing a promising strategy for the rational design of multifunctional amorphous CUR-based drug formulations. Full article

This research highlights the mechanical performance of alkali-activated polypropylene fiber (PPF) mortar containing natural pozzolan (NP) and waste glass powder (WGP) as partial replacements for cement. A total of 45 mix combinations and 405 samples were prepared by varying the levels of NP, WGP, PPF, and sodium silicate (SS), with sodium hydroxide (SH) as an alkali activator. The levels for these variables are NP (0%, 10%, and 20%) and WGP (0%, 10%, 20%, and 30%) by weight of the cement; PPF (0%, 0.5%, and 1.5%) by volume of mortar; and SS + SH (30%, 40%, and 50%) by weight of the binder. The molarity of the SH solution was kept at 10 M, while the SS/SH ratio was maintained at 2.5. Compressive (f’c), flexural (fr), and split tensile strength (ft) were evaluated at 7, 28, and 90 days. The results showed that strength development is strongly age-dependent, with 85–90% of the total strength achieved at 28 days and continued moderate gains to 90 days. SS + SH was the most significant variable, with 50% of activator content achieving the highest f’c, fr, and ft values. Within the tested ranges of NP (0–20%) and WGP (0–30%), strength showed a decreasing trend with increasing replacement due to dilution. PPF had a very minute effect on f’c but significantly improved fr and ft at 0.5% dosage because of crack-bridging. Correlation analysis confirmed that cement and SS + SH are the most dominant strength-controlling factors. The results suggest that the combined use of NP, WGP, and PPF maintains mechanical performance while reducing cement consumption, highlighting the feasibility of this hybrid alkali-activated mortar as a low-carbon construction material. Full article

The global production of electronic waste (e-waste) has increased due to the quick turnover of electronic devices, creating urgent problems for resource management and environmental sustainability. As a result, e-waste-derived materials (EWDMs) are being explored in pavement engineering research as sustainable substitutes in line with Sustainable Development Goals (SDGs), specifically SDG 9 (Industry, Innovation, and Infrastructure), 11 (Sustainable Cities and Communities), 12 (Responsible Consumption and Production), and 13 (Climate Action). Therefore, to assess global research production and the effectiveness of EWDMs in asphalt applications, this review combines scientometric mapping and systematic evidence synthesis. A total of 276 relevant publications were identified via a thorough search of Web of Science, Scopus, and ScienceDirect (2010–2025). These were examined via coauthorship structures, keyword networks, and contributions at the national level. The review revealed that China, India, and the United States are prominent research hubs. Additionally, experimental studies have shown that EWDMs, such as printed circuit board powder, fluorescent lamp waste glass, high-impact polystyrene, and acrylonitrile–butadiene–styrene, improve the fatigue life, Marshall stability, rutting resistance (up to 35%), and stiffness (up to 28%). However, issues with long-term field durability, microplastic release, heavy metal leaching, and chemical compatibility still exist. These restrictions highlight the necessity for standardised toxicity testing, harmonised mixed-design frameworks, and performance standards unique to EWDMs. Overall, the review shows that e-waste valorisation can lower carbon emissions, landfill build-up, and virgin material extraction, highlighting its potential in the circular pavement industry and promoting sustainable paving practices in accordance with SDGs 9, 11, 12, and 13. This review suggests that further studies on large-scale field trials, life cycles, and technoeconomic assessments are needed to guarantee the safe, long-lasting integration of EWDMs in pavements. It also advocates for coordinated research, supportive policies, and standardised methods. Full article

Titanium-based bulk metallic glasses (BMGs) offer high strength, lower stiffness than Ti-6Al-4V, and superior corrosion resistance, but conventional Ti glass-forming systems often contain toxic Ni, Be, or Cu. This work investigates five novel Ti-based alloys free of these elements—Ti₄₂Zr₃₅Si₅Co_12.5Sn_2.5Ta₃, Ti₄₂Zr₄₀Ta₃Si₁₅, Ti₆₀Nb₁₅Zr₁₀Si₁₅, Ti₃₉Zr₃₂Si₂₉, and Ti_65.5Fe_22.5Si₁₂—synthesized by arc melting and suction casting. Single-track laser remelting using a selective laser melting (SLM) system was performed to simulate additive manufacturing and examine microstructural evolution, cracking behavior, mechanical properties, and cytocompatibility. All alloys solidified into fully crystalline α/β-Ti matrices with Ti/Zr silicides; no amorphous structures were obtained. Laser remelting refined the microstructure but did not induce glass formation, consistent with the known limited glass-forming ability of Cu/Ni/Be-free Ti systems. Cracking was observed at low laser energies but crack density decreased as laser energy increased. Cracks were eliminated above ~0.4 J/mm for most alloys. Ti₄₂Zr₃₅Si₅Co_12.5Sn_2.5Ta₃ exhibited the lowest stiffness (~125 GPa), while Ti₆₀Nb₁₅Zr₁₀Si₁₅ showed the highest due to silicide precipitation. Cytotoxicity tests (ISO 10993-5) confirmed all alloys to be non-toxic, with some extracts even enhancing fibroblast proliferation. This rapid laser-remelting approach enables cost-effective screening of Ti-based glass-forming alloys for additive manufacturing. Ti–Zr–Ta–Si systems demonstrated the most promising properties for further testing using the powder bed method. Full article