Search Results (638)

Multilayer packaging—engineered by integrating complementary materials such as plastics, paper, and aluminum—has become a cornerstone technology for enhancing shelf life, minimizing spoilage, and reinforcing the mechanical integrity of packaging formats including films, pouches, and bottles. In this study, a laminate was developed by thermally bonding polylactic acid (PLA) with a poly(butylene adipate-co-terephthalate) (PBAT)/thermoplastic starch (TPS) matrix embedded with silver nanoparticles (Ag-NPs) at 0–3 wt.%. The resulting structures were systematically evaluated for their barrier performance, physicochemical characteristics, and antimicrobial functionality. Fourier-transform infrared (FTIR) spectroscopy confirmed the absence of chemical interactions between Ag-NPs and the polymer matrix, indicating physical dispersion rather than chemical bonding. However, at higher loading (3 wt.%), scanning electron microscopy with energy-dispersive X-ray spectroscopy (SEM-EDX) revealed notable nanoparticle aggregation. Functionally, the multilayer films demonstrated markedly improved water vapor barrier properties compared to single-layer PBAT/TPS films. Migration studies showed that silver release increased with nanoparticle concentration and was significantly enhanced under acidic conditions relative to distilled water. Importantly, Ag-NP-incorporated laminates exhibited pronounced antibacterial activity against Staphylococcus aureus. Collectively, these findings highlight the potential of Ag-NP-enriched, starch-based multilayer laminates as next-generation active packaging systems that combine with effective microbial control. Full article

Most water supply systems rely on free chlorine residual to ensure disinfection through the network and at the user’s tap. Temperature increase is known to accelerate the chlorine decay process and is typically associated with water quality deterioration. This is a challenging situation under the current climate change scenario, which is bound to increase average temperatures and the intensity and frequency of extreme-temperature events. Moreover, water temperature varies through the supply network due to seasonal changes and thermal interaction, so it is not straightforward to model chlorine evolution through the network considering temperature effects. Previous works have highlighted the importance of considering the Arrhenius formula when accounting for temperature changes in the bulk chlorine decay coefficient (typically characterized through bottle tests), but these studies have never explicitly considered the uncertainty of the bulk decay coefficient itself. Recent studies have identified that the uncertainty of the bulk decay coefficient may be relevant (>15%) and should be considered when cross-comparing bottle test results (e.g., at different temperatures). The aim of this work is to propose a new method that statistically computes the mean and standard deviation of the key parameters in the Arrhenius formula (the reference bulk decay coefficient $k_{b_0}$ and activation coefficient E/R) from free chlorine residual bottle test results (with replicated measurements over samples from the entrance to the network) at different temperatures. This approach (here called the ensemble temperature state estimation approach) ensures that bottle test measurements at different temperatures are jointly assessed to derive an equation that provides the bulk decay coefficient at any water temperature. Therefore, the new method improves the characterization of the bulk decay component (and its associated uncertainty) and could be crucial for improving the understanding and modeling capabilities of complex chlorine dynamics within supply infrastructure. Full article

The recycling of polyethylene terephthalate (PET) into value-added products suitable for additive manufacturing remains challenging due to molecular degradation and insufficient melt strength. In this study, post-consumer recycled PET was upcycled via chain extension to develop filaments suitable for fused filament fabrication (FFF). Two chain extenders were evaluated: an epoxy-based multifunctional oligomer (Joncryl^® ADR-4468) and a tetrafunctional aromatic dianhydride (pyromellitic dianhydride, PMDA). Joncryl^® ADR-4468 increased the complex viscosity and viscoelastic moduli of rPET; however, the response was non-monotonic and resulted in limited filament dimensional stability. In contrast, rPET/vPET (70/30) blends modified with PMDA exhibited a pronounced and reproducible enhancement in melt viscosity and elasticity, enabling the production of a continuous filament with a stable diameter (1.75 ± 0.05 mm). Differential scanning calorimetry indicated that PMDA had a negligible effect on the glass transition temperature, while slightly reducing crystallinity, which is beneficial for FFF processing. Preliminary printing trials confirmed stable extrusion and controlled deposition behaviour for the PMDA-modified formulation. Overall, the results demonstrate that chain extension using PMDA is an effective strategy to restore melt processability and enable the use of recycled PET in filament-based additive manufacturing. Full article

This study investigated the influence of solvent evaporation on the ultimate tensile strength (UTS) and water-related weight changes in contemporary universal dental adhesives. Two two-step universal adhesives (OptiBond eXTRa Universal and G2-BOND Universal) and two one-step universal adhesives (OptiBond Universal and BeautiBond Xtreme) were evaluated. Adhesives were used either under normal storage conditions or after active solvent evaporation by removal of the bottle caps and storage at 37 °C for 2 weeks. Hourglass-shaped specimens were prepared, light-cured, and stored in water at 37 °C for 1 h or 7 days prior to UTS testing (n = 10). Specimen weights were measured before and after water storage. For OptiBond eXTRa Universal, no significant difference in UTS was observed between the original and desiccated groups after 7 days of water storage (p > 0.05). In contrast, G2-Bond Universal exhibited significantly higher UTS values in the desiccated group compared with the original group (p < 0.05). In the original group, the one-step universal adhesives failed to polymerize under the original (non-evaporated) conditions, whereas adequate polymerization was achieved following active solvent evaporation. Weight changes after water storage varied depending on the adhesive composition. These results suggest that residual solvent may influence the polymerization behavior, mechanical performance, and water-related properties of universal dental adhesives, emphasizing the importance of adequate solvent evaporation before light curing. Full article

Background/Objectives: Sex differences in ethanol consumption have been reported in both humans and laboratory rodents, but the independent/dependent contributions of genetic and hormonal sex biasing mechanisms to these phenotypes have not yet been fully explored. Methods: To examine the contributions of sex-chromosome complement (SCC) and gonadal sex (GS) to ethanol consumption, we studied adolescent (28–32 days old) four core genotypes (FCG) mice on a C57BL/6J background, a model which allows for independent assortment of GS and SCC. A modified drinking-in-the-dark (DID) procedure was employed, in which mice were offered concurrent access to 20%, 10% and 0% ethanol (in water) in four daily 2 h sessions. Consumption at the level of individual bouts was recorded. Results: Overall ethanol intake differed substantially by group and was driven almost entirely by differences in consumption of the 20% ethanol solution; all groups preferred the 20% solution over the 10% and 0% solutions, but consumed similar amounts of the 10% and 0% solutions. Intake of the 20% ethanol solution followed the rank order XXM > XYM > XYF > XXF. This pattern reflects an interaction between SCC and GS, such that SCC effects were greatest in gonadal females (XY > XX), whereas GS effects were greatest in XX mice (gonadal males > gonadal females). Moreover, the magnitude of these effects varied both across and within drinking sessions. The behavioral microstructure of ethanol consumption (i.e., parameterization of within-session discriminable drinking bouts) support the validity of our three-bottle modification of the DID procedure as a model of binge-like consumption, because (1) the consumption rate of the 20% ethanol solution was ~80 g EtOH/kg/h within a bout (~12 s/bout, ~three bouts/session), (2) most of this ethanol consumption was completed in a single bout and (3) within-session ethanol consumption was greater earlier than later, indicating “front loading.” Conclusions: These results suggest that the effects of GS on binge-like ethanol consumption are observed in early adolescence and moderated by SCC in adolescent FCG mice, with GS effects most pronounced in XX mice and SCC effects evident mainly in gonadal females. Full article

Bottled drinking water is widely consumed in Saudi Arabia; however, the chemical composition of these products and the accuracy of the information presented on their labels remain insufficiently characterized. This study evaluated the composition of 41 still bottled waters purchased from major supermarkets in Riyadh, Saudi Arabia, with emphasis on fluoride, calcium, magnesium, sodium, potassium, hardness, and pH, and examined their potential contributions to dietary mineral intake and caries-preventive fluoride exposure. Products were categorized according to label descriptions, and elemental analyses were performed using a fluoride ion-selective electrode for fluoride and ICP-MS for calcium, magnesium, sodium, and potassium. The pH was measured using a calibrated multiparameter analyzer, and hardness was calculated from calcium and magnesium concentrations. Mineral and purified waters accounted for 75.6% of the sampled products. Fluoride concentrations were generally modest (mean 0.76 ppm; median 0.74 ppm), indicating that the potential contribution of bottled water to caries prevention may vary substantially by brand, and only one product would provide the adult adequate intake for fluoride at a hypothetical intake of 2 L/day. Mean concentrations of calcium, magnesium, sodium, and potassium were 15.10, 7.19, 12.08, and 3.55 mg/L, respectively, indicating limited nutritional significance for most products. Most waters were soft to moderately hard, and pH values were close to neutral. Agreement between label declarations and measured values was inconsistent for fluoride, calcium, and pH. These findings show that bottled waters sold in Riyadh differ considerably in composition and that product labels do not always provide a reliable estimate of fluoride content, mineral content, or pH. From a water quality and public health perspective, bottled water can contribute to daily intake of selected constituents, but in most cases, this contribution is modest and highly brand dependent. Full article

Reliable surveillance of dissolved ²²²Rn in arid-region aquifers is challenged by very low natural activity and method-dependent biases, especially humidity sensitivity in electrostatic detectors and air–water partitioning during closed-loop aeration, which can obscure true concentrations needed for defensible drinking-water baselines under preventive frameworks. This study aimed to optimize and field-validate a low-background RAD7 Big-Bottle (RAD H₂O) closed-loop protocol tailored for arid conditions and apply it in a regional survey of groundwater used for potable supply in northeastern Saudi Arabia. Groundwater from wells across the region (shallow and deep completions) was collected and analyzed using isotope-resolved alpha spectroscopy (Po-218 and Po-214 windows) with strict chamber humidity control (≤7% RH), background checks, systematic blanks, duplicates, drift control (±10%), and uncertainty propagation. Air-phase chamber counts were mandatorily converted to water-phase activity using the CAPTURE parameterized by measured loop volumes, temperature, salinity, and humidity, and agreement was evaluated using regression diagnostics and Bland–Altman analysis. The optimized method achieved sub-Bq·L⁻¹ performance, with MDL improving from ~0.1645 Bq·L⁻¹ (30 min) to ~0.0233 Bq·L⁻¹ (1500 min) and ~0.0165 Bq·L⁻¹ (3000 min), and LOQ decreasing from ~0.50 to ~0.0707 and ~0.050 Bq·L⁻¹, respectively. Raw air-phase readings systematically overestimated dissolved radon by ~26% (slope ≈ 1.26), a bias removed by the validated air → water conversion. Surveyed ²²²Rn concentrations were uniformly low (0.03–3.20 Bq·L⁻¹), far below commonly used reference values (e.g., ~11.1 and ~100 Bq·L⁻¹), with no persistent spatial hotspots and broadly overlapping shallow/deep distributions, indicating variability dominated by local lithology and fracture-controlled flow rather than depth. A tiered monitoring scheme is recommended: short screening, routine baselining at ~900–1500 min total counting, and ~3000 min for ultralow verification, providing a transferable template for sustainable baseline programs in arid aquifers. Full article

The potato chip processing (PCP) industry generates huge amounts of wastewater heavily polluted with organic matter and nutrients. The current treatment technology of PCP wastewater uses dissolved air flotation (DAF) and an activated sludge sequential batch reactor (SBR); both consume large amounts of chemicals and represent energy-intensive systems. This study explores the utilization of algae for the sustainable treatment of PCP wastewater, nutrient recovery, and algal biomass production. Conical flasks (1-L) and 6-L transparent plastic bottles were used as lab-scale algae photobioreactors (APBRs). Raw wastewater, an anaerobically pre-treated effluent and a DAF–SBR or shortly SBR effluent were used in the first, second, and third APBR. Three feed volumes from each source (150 mL, 300 mL, and 500 mL for first and second APBR and 400 mL, 600 mL, and 800 mL for third APBR) to a fixed volume of algal seed (200 mL) were tested to select the optimal feed volume and harvest time using a 1-L APBR. System performance and impact of water characteristics on quantity and quality of algal biomass were explored at pre-selected feed volume and harvest time in 6-L APBRs. All experiments were carried out in a growth chamber with continuous light (148.75 μmol.m⁻².S⁻¹). The results showed that 150 mL is the optimal feed volume for the first and second APBR at 10 days and 9 days growth cycles. An amount of 500 mL and 6 days were selected as the optimal feed volume and growth cycle for the third APBR. The average dry biomass yields at the pre-selected optimal conditions were 65.3 ± 11.4, 69.9 ± 12.0, and 100.6 ± 11.7 mg/L.d in the first, second, and third APBR, respectively. The first APBR achieved removals of 99.2 ± 0.4%, 98.7 ± 0.8%, 89.1 ± 4.3%, and 97.5 ± 1.4% for turbidity, COD, TKN, and TP, respectively, on average. Corresponding removal in the second APBR is 97.6 ± 2.6%, 91.6 ± 7.5%, 93.6 ± 4.5%, and 96.1 ± 1.4%, respectively, while the third APBR achieved 98.5%, 76.2%, and 97.0%, respectively. Additionally, the results of protein content and amino acids profiles indicate significant impacts of feed water quality on both parameters. The protein content was 30.64%, 32.53%, and 35.65% in the first, second, and third APBR, respectively. Similarly, the amino acids profile indicated a significant higher percentage of the amino acids in the third reactor compared with the first and second reactor. Full article

Reliable estimates of volumetric water content at field capacity (θFC) are important inputs for irrigation scheduling because θFC contributes to the estimation of plant-available water, depletion thresholds, and refill targets. In irrigated systems, θFC is therefore an operational decision variable rather than a fixed soil property. However, θFC varies systematically across estimation methods, introducing uncertainty into irrigation management. This study evaluated method-dependent differences in θFC for irrigated tropical soils in the Roldanillo–Unión–Toro agricultural irrigation district (Valle del Cauca, Colombia). Field capacity was estimated at 42 sampling points (0–0.10 m depth) using four methods: Mariotte bottle (MB), filter paper (FP), a pedotransfer function (PTF), and the Richards pressure plate method (RPP). The RPP method was used as an operational reference for comparative purposes, not as an absolute representation of true FC. Agreement and bias were assessed using descriptive statistics, error metrics, regression, Bland–Altman analysis, and texture-stratified comparisons. RPP θFC averaged 39.37% (range: 29.85–46.41%), whereas MB, FP, and PTF produced higher mean values of 42.66%, 44.26%, and 46.38%, respectively. Relative to RPP, mean error and root mean square error increased from MB (3.29% and 5.21%) to FP (4.89% and 8.16%) and PTF (7.01% and 10.82%). Disagreement also varied with soil texture. These results show that low-cost θFC methods are not directly interchangeable with RPP measurements in the evaluated surface layer. Because θFC is commonly used in irrigation calculations, the observed method-dependent differences may affect the estimation of depletion thresholds and refill targets if surface-layer values are extrapolated without local validation. Overall, surface-layer θFC in the Roldanillo–Unión–Toro irrigation district was strongly method-dependent, highlighting the need to account for method-related uncertainty before using alternative θFC estimates as inputs for irrigation decision support. Full article

Disinfection is essential to ensure safe drinking water and hygienic conditions in environmental, industrial, and clinical settings. However, conventional methods for monitoring free residual chlorine are often laboratory-based and not suited for decentralized analysis. Here, we report a novel paper-based colorimetric biosensing platform that translates the ISO 7393-2 standard, a method based on the reaction of chlorine with N,N-diethyl-p-phenylenediamine (DPD), into a portable and user-friendly format. The proposed device integrates the DPD chemistry within a paper architecture, enabling reagent-free operation at the point of need. The sensor provides a rapid visual readout that is detectable by the naked eye, while quantitative analysis is achieved within 3 min through smartphone-based image acquisition. This work constitutes the first implementation of the ISO standard in a portable paper-based format suitable for both environmental and clinical matrices. The sensor provided a detection limit of 12 μM for sodium hypochlorite and was successfully validated in real samples, including bottled water and exhaled breath condensate, with satisfactory recoveries. Furthermore, the stability of the paper-based sensor was assessed under storage conditions of 4 °C and room temperature (23 °C), demonstrating excellent performance over 30 days in both cases, indicating that refrigeration is not required for maintaining sensor performance. Full article

The present study aimed to investigate the migration of potentially hazardous compounds from plastic food packaging into edible oils, bottled water and soft drinks available on the market in the Republic of Moldova. GC–MS screening was applied to identify plastic additives and unintentionally added substances (NIAS). The influence of key extraction parameters, including solvent type, extraction time, pH, alcohol content and sugar concentration, was systematically investigated. The optimized procedure demonstrated satisfactory analytical performances, with recoveries ranging from 81 to 96%, repeatability below 5% and detection limits between 0.006 and 0.01 mg/L. To allow a comprehensive assessment of total phthalate contamination, an additional analytical approach based on the hydrolysis of phthalate esters and the determination of o-phthalic acid using capillary electrophoresis with spectrophotometric detection was proposed. The method showed a linearity range of 0.1–5.0 mg/L and a limit of quantification of 0.07 mg/L. The combined chromatographic and hydrolysis-capillary electrophoresis approaches provide a reliable tool for the integrated determination and evaluation of phthalate residues in aqueous-alcoholic systems and beverages, accessible to laboratories performing food quality control. Full article

Background/Objectives: Gastro-resistant multiparticulate systems are designed to protect drugs in acidic environments and to ensure intestinal release. In practice, the method of administration may need to be modified: pellet-containing capsules opened or tablets halved for patients with swallowing difficulties, yet the type of liquid used for administration is often not specified. This study examined the stability of gastro-resistant coated pellets after exposure to various aqueous media prior to ingestion. Methods: To evaluate administration instructions, 103 Summaries of Product Characteristics of gastro-resistant products were reviewed. Pellets were produced using a bottom-spray fluidized bed process and coated with Eudragit L 30 D-55. Dissolution testing in pH 1.2 medium was performed after pre-soaking the pellets for 5, 15, and 30 min in beverages with various pH and conductivity. Drug release was measured by UV-VIS method, and morphological changes were assessed by image analysis. Marketed gastro-resistant products were also examined visually. Results: SmPC review revealed that the beverage for intake was frequently unspecified. Among the tested beverages differences in pH and conductivity were observed. Alkaline medicinal mineral waters induced increased and time-dependent premature drug release compared to tap and filtered water. Image analysis indicated a reduction in surface area after exposure to alkaline media. Conclusions: Contact with non-specified aqueous media before swallowing may weaken the protective function of gastro-resistant films. More explicit recommendations on suitable administration manipulation and media may improve therapeutic consistency. Full article

Heavy metal contamination in drinking water remains a pervasive global challenge with significant consequences for environmental quality and human health. This review synthesizes findings from recent studies examining heavy metal concentrations in different sources of drinking water, including municipal tap water, groundwater, surface water, and bottled/sachet water across various geographical regions. The study used a systematic review of studies published from 2015 to 2024. The result showed a variation in the concentrations of heavy metals from all the sources, with tap water generally exhibiting lower heavy metal levels. Pb, Fe, Mn, and other metals persist in different sources and from many regions with levels above the permissible limits recommended by the World Health Organization (WHO) in some instances, which were sometimes linked to aging distribution systems and other pollution sources. Bottled and sachet water, commonly regarded as safer alternatives, also showed some levels of heavy metals such as Pb, Cd, and Cr, reflecting inconsistent packaging or production oversight. Surface waters display variability with heavy metals pollution, driven by industrial discharge, mining activities, agricultural runoff, and urban wastewater inputs. Groundwater sources, although naturally shielded, frequently contained elevated concentrations of As, Hg, and Ni due to both geological and anthropogenic factors. Pb concentrations were below detection limit in some of the published papers; however, the values reported in this study ranged from ND to 260.0 µg/L (tap water), ND to 0.259 mg/L (surface water), ND to 0.791 mg/L (groundwater), and ND to 123.15 µg/L (bottled water). Arsenic (As) concentrations ranged from ND to 692 µg/L from different sources, with the highest concentration from groundwater. Collectively, these patterns underscore the need for strengthened monitoring frameworks, improved water treatment technologies, and integrated pollution-prevention strategies. Addressing heavy metal contamination in drinking water requires coordinated policy approach and continuous monitoring to reduce human exposure and safeguard global public health. Full article

This study employs a constructivist grounded theory approach based on 69 in-depth interviews conducted between March 2022 and December 2023 to examine socio-cognitive dynamics in Korea’s bottled water and household water purifier markets. The study addresses a gap in prior research by explaining how product meanings and stakeholder strategies co-evolve across adjacent “safe-water” markets under regulatory and sustainability pressures. Drawing on qualitative data from 69 stakeholders, including producers (n = 30), consumers (n = 19), and institutional experts (n = 20), we analyze how distrust, risk perception, and health consciousness reshape conceptual systems and market strategies. These shifts drive innovation across markets, including new technologies, service models, and branding strategies. The findings show that socio-cognitive stabilization arises through iterative interactions among institutional shocks, producer reinterpretation, and consumer adaptation. In the bottled water market, the meanings of “natural purity” became materially embedded in packaging, mineral labeling, and brand narratives. In the purifier sector, “technological reliability” was institutionalized through service-based maintenance systems and visible quality control technologies. These processes developed within asymmetric communicative environments shaped by corporate branding capacity and media amplification. This study refines socio-cognitive market theory by specifying boundary conditions under institutional distrust in developed economies. Although Republic of Korea possesses advanced drinking water infrastructure comparable to that of other developed economies, public confidence in tap water has periodically weakened following highly salient contamination incidents and regulatory transitions. This paradox provides a theoretically informative context for examining how product meanings and stakeholder behaviors mutually adapt over time. Although environmental impact metrics were not directly measured, the findings suggest that sustainability policies must address socio-cognitive trust dynamics alongside regulatory instruments such as plastic levies, certification schemes, and transparent risk communication. Full article

In this paper, the target compound, 4-hydroxy-3-[[(2-hydroxy-1-naphthalenyl)methylene]amino]benzenesulfonamide (hereafter referred to as HA), was synthesized via the reaction of 2-hydroxy-1-naphthaldehyde with 2-aminophenol-4-sulfonamide in an 86% yield. In methanol–water (v/v, 1:1, pH 5.0 acetate buffer), HA displays a “turn-on” fluorescence response at 531 nm (λex = 411 nm) toward Al³⁺ with high selectivity over 17 common metal ions and 11 anions. The fluorescence intensity is linearly correlated to an Al³⁺ concentration from 1 to 10 µM (R² = 0.999) with a detection limit of 58 nM (3σ/k). Job’s plot and DFT calculations (M06/6-31G) both support a 1:1 binding stoichiometry. Under the tested conditions (with the methanol–water medium having an effective ionic strength equivalent to a low-salinity environment), the probe’s performance was unaffected. In natural aqueous samples (tap water and bottled water), which typically have low salinity (estimated as 0–5‰), Al³⁺ in the samples can also be chelated by the HA probe with a precision of relative standard deviation of less than 1%, and the recovery rate is higher than 90%. The probe exhibited acceptable relative recovery and low standard deviation, demonstrating a rapid and convenient novel method for detecting Al³⁺ in a natural aqueous sample. Full article