Search Results (27,293)

This study investigated the efficacy of Isomalt-containing toothpaste in preventing development of dental caries. Methods: Human dental enamel slabs were allocated to six groups (30/group) at random: De-ionized distilled water (DDW), and toothpaste containing 10% Isomalt, 1100 ppm fluoride, 0.05% cetylpyridinium chloride [CPC] (ICT); 10% Isomalt, 1100 ppm fluoride (IT); 10% Isomalt, 1100 ppm fluoride, 1.5% Sodium lauryl sulfate [SLS] (IST); 1100 ppm fluoride only (FT); 1100 ppm fluoride with SLS (FST). The enamel slabs were exposed to caries development via plaque growth in a Microbial Caries Model for 7 days. Toothpastes were applied as slurries (one toothpaste–three DDW) for 2 min twice daily. Demineralization was measured as the change in surface microhardness (ΔSMH) and amount of mineral lost (∆Z), and these metrics were assessed using Transverse Microradiography. Intra-group (SMH) and intergroup (%∆SMH and ∆Z) comparisons were paired t-test and Tukey’s test (α = 0.05), respectively. Results: With SMH, demineralization was found to be significant (p < 0.001) in all groups compared to sound enamel baseline, except ICT group. With %ΔSMH, all other groups had significantly (p < 0.001) less demineralization compared to DDW. Significantly (p < 0.001) greater demineralization was observed in IT, FT and FST compared to ICT, and no significant difference was observed between IST and ICT or FT. With ∆Z, relative to the DDW group, the inhibition of demineralization was significant (p < 0.0001) in all groups at varying percentages. Conclusions: Toothpaste containing 10% Isomalt, 1100 ppm fluoride, and 0.05% CPC demonstrated greater efficacy in inhibiting caries development amid dental plaque compared to toothpaste containing only 1100 ppm fluoride. Full article

The wettability of the proppant is crucial in optimizing the flowback of fracturing fluids and improving the recovery of the produced hydrocarbons. Neutral wet proppants have been proven to improve the fluid flow by reducing the interaction between the fluid and the proppant surface. In this study, a lightweight amphiphobic proppant (LWAP) was prepared by coating a lightweight ceramic proppant (LWCP) with phenolic resin, epoxy resin, polytetrafluoroethylene (PTFE), and trimethoxy(1H,1H,2H,2H-heptadecafluorodecyl)silane (TMHFS) using a layer-by-layer method. The results indicated that the LWAP exhibited a breakage ratio of 2% under 52 MPa (7.5 K) closure stress, with an apparent density of 2.12 g/cm³ and a bulk density of 1.21 g/cm³. The contact angles of water and olive oil were 125° and 104°, respectively, changing to 124° and 96° after displacement by water and diesel oil. A comparison showed that the LWAP could transport over a significantly longer distance than the LWCP, with the length increasing by more than 80%. Meanwhile, the LWAP displayed notable resistance to scale deposition on the proppant surface compared to the LWCP. Furthermore, the maintained conductivity of the LWAP was higher than that of the LWCP after displacement by water and oil phases alternately. The modified proppant could minimize production declines during hydrocarbon extraction in unconventional reservoirs. Full article

The leading cause of hospital-acquired infections worldwide includes Enterococcus faecium, Staphylococcus aureus, Klebsiella pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa, and Enterobacter spp. (ESKAPE) infections. These bacteria are commonly isolated from clinical settings and linked to a number of potentially fatal diseases associated with hospitals. The objective of this study was to review the prevalence of ESKAPE pathogens in Africa. We gathered and systematically reviewed the literature concerning the prevalence of ESKAPE pathogens, published in the English language from January 2014 to February 2024, from three databases (PubMed, Web of Science and ScienceDirect). Our overall results revealed that S. aureus was the most prevalent species (79.5%), followed by A. baumannii (27.6%), K. pneumoniae (24.2%), Enterobacter spp. (20%), P. aeruginosa (9.0%), and E. faecium (5.1%). Moreover, stool samples had the highest Pooled Prevalence Estimates (PPEs) of 44.0%, followed by urine, nasal, and blood samples with 37.3%, 26.9%, and 22.9%, respectively. For the diagnostic method used to identify these ESKAPE pathogens, VITEK-MS had the highest PPE of 55.2%, followed by whole genome sequencing and PCR with 37.1% and 33.2%, respectively. The highest PPE of ESKAPE pathogens was recorded in West Africa with 77.3%, followed by Central/Middle Africa and East Africa with 43.5% and 25.1%, respectively. The overall PPE of ESKAPE pathogens from humans, animals, the environment (water, soil, and surfaces) and food sources was 35.8%, 37.3%, 47.7%, and 34.2%, respectively. Despite their prevalence in nosocomial settings, studies have shown that the ESKAPE pathogens may be isolated from a range of environmental reservoirs, including soil, dumping sites, beach sand, wastewater, food, and fish farms, among others. This wide source of ESKAPE pathogens substrates indicates the need for a multidisciplinary collaborative partnership for epidemiological studies and intervention efforts by the human, veterinary, and environmental health sectors in Africa. Full article

Coated SS316L is a potential alternative to the graphite bipolar plates (BPPs) used in proton-exchange membrane fuel cells (PEMFCs) owing to their low manufacturing cost and machinability. Due to their susceptibility to corrosion and passivation, which increases PEMFC ohmic resistance, protective and conductive coatings on SS316L have been developed. However, coating adhesion is one of the challenges in the harsh acidic environment of PEMFCs, affecting the performance and durability of BPPs. This study compares mechanical polishing and the frequently adopted chemical etchants for SS316L: Adler’s, V2A, and Carpenter’s etchant with different etching durations and their impact on the wettability, adhesion, and corrosion resistance of a Nb-coated SS316L substrate. Contact angle measurements and laser microscopy revealed that all etching treatments increased the hydrophobicity and surface roughness of SS316L substrates. Ex situ potentiodynamic and potentiostatic polarization tests and interfacial contact resistance analysis revealed high corrosion resistance, interfacial conductivity, and adhesion of the Nb-coated SS316L substrate pretreated with V2A (7 min) and Adler’s (3 min) etchant. Increased hydrophobicity (contact angle = 101°) and surface roughness (R_a = 74 nm) achieved using V2A etchant led to the lowest corrosion rate (3.3 µA.cm⁻²) and interfacial resistance (15.4 mΩ.cm²). This study established pretreatment with V2A etchant (a solution of HNO₃, HCl, and DI water (1:9:23 mole ratio)) as a promising approach for improving the longevity, electrochemical stability, and efficiency of the coated SS316L BPPs for PEMFC application. Full article

The aim of this in vitro study was to evaluate the effectiveness of highly concentrated fluoride products and remineralizing products (F-APC) in preventing erosive dental lesions in competitive swimming patients. A total of 48 teeth were extracted, preserved in saline solution and divided into three groups. In G1 (control group), each tooth was half-immersed in chlorinated pool water; in G2 (fluoride-treated group), after being totally immersed in chlorinated water, each tooth had half of its surface treated with a highly concentrated fluoride product once a week; in G3 (remineralization product-treated group), each tooth was totally immersed in chlorinated water and half of its surface was treated with a remineralizing product after each immersion. The study was conducted over a 4-week period, immersing the teeth for 4 h per day. In G1, statistically significant differences were observed in submerged versus non-submerged tooth surfaces at week 3 (T3) (p = 0.019) and week 4 (T4) (p = 0.0007), with four and eight surfaces showing erosive tooth wear (ETW), respectively. In G2, a difference was observed between fluoride-treated and non-fluoride-treated surfaces at T4 (p = 0.039), with three surfaces with ETW among the non-treated ones. In G3, the difference was observed between portions treated with F-APC and those not treated at T4 (p = 0.019), with four surfaces with ETW among the untreated ones. Chlorinated pool water is a potential erosive agent for teeth if water pH values reach a critical value. Treating the teeth surface with highly concentrated fluoride products, once a week for 5 min, and F-APC are effective in protecting teeth against tooth erosion. Full article

The detection of unknown waters has been studied and applied in various fields, such as national defense, military operations, engineering surveying and mapping, and scene reconstruction. To improve exploration efficiency in unknown waters, this paper proposes a framework for autonomous exploration using unmanned surface vehicles (USVs). This framework, comprising a multi-stage exploration strategy and a hierarchical navigation strategy, is designed to mitigate the inherent restrictions between the exploration target point and exploration direction in USV operations. These two strategies are optimized for the exploration target point and feasible navigation route to address the problem of the USV’s limited mobility during exploration. Rapidly exploring random tree (RRT) and boundary detection methods are used in the local layer to find the boundary in front of and behind the USV, and the gain of the target point is optimized. The hierarchical navigation method is implemented in the global layer to plan appropriate navigation paths. The proposed method is tested in simulations in several virtual environments and contrasted with the conventional methods currently in use. The findings indicate that our strategy covers more ground more effectively than other methods (our method achieved an exploration efficiency ranging from 4.9 to 5.3 m2/s, whereas traditional methods ranged from 2.3 to 3.9 m2/s, which demonstrates that our approach can improve exploration efficiency by up to 200% compared to traditional methods), spending less time exploring while significantly reducing collision probability. Full article

Greenscaping, a key sustainable practice, helps cities combat rising temperatures and climate change. Urban parks, a pivotal greenscaping element, mitigate the urban heat island (UHI) effect. In this study, we utilized high-resolution remote sensing imagery (GF-2 and Landsat 8, 9) and in situ measurements to analyze the seasonal thermal regulation of different park types in Zhengzhou, China. We calculated vegetation characteristic indices (VCIs) and landscape patterns (LMs) and employed boosted regression tree models to explore their relative contributions to land surface temperature (LST) across different seasons. Our findings revealed that urban parks lowered temperatures by 0.65 °C, 1.41 °C, and 2.84 °C in spring, summer, and autumn, respectively, but raised them by 1.92 °C in winter. Amusement parks, comprehensive parks, large parks, and water-themed parks had significantly lower LSTs. The VCI significantly influenced LST in autumn, with trees having a stronger cooling effect than shrubs. LMs showed a more prominent effect than VCIs on LST during spring, summer, and winter. Parks with longer perimeters, larger and more dispersed green patches, higher plant species richness, higher vegetation heights, and larger canopies were associated with more efficient thermal reduction in an urban setting. The novelty of this study lies in its detailed analysis of the seasonal thermal regulation effects of different types of urban parks, providing new insights for more effective urban greenspace planning and management. Our findings assist urban managers in mitigating the urban surface heat effect through more effective urban greenspace planning, vegetation community design, and maintenance, thereby enhancing cities’ potential resilience to climate change. Full article

The shortage of water resources seriously limits sustainable production in agriculture, and the ridge–furrow planting pattern is an effective water-saving cultivation pattern. However, the mechanism of the ridge–furrow planting pattern that drives the efficient utilization of field water resources in the North China Plain (NCP) is still unclear. A two-year field experiment was conducted in the NCP from 2021 to 2023. The ridge–furrow planting patterns followed a randomized block design as follows: ridge–furrow ratios of 50 cm:50 cm (M2), 75 cm:50 cm (M3), and 100 cm:50 cm (M4). A traditional planting pattern was used as the control (M1). These were used to investigate the effects of different treatments on water use and roots. The results showed that M3 reduced the amount of irrigation, improved water distribution after irrigation, increased water use efficiency (WUE), and promoted root growth. Compared with other treatments, M3 increased soil water consumption at a 0–100 cm soil depth by 6.76–21.34% (average values over two years), root length density by 8.46–20.77%, and root surface area density by 7.87–22.13%. On average, M3 increased grain yields by 3.96–9.80%, biomass yields by 5.32–10.94%, and WUE by 4.5–9.87%. In conclusion, M3 is an effective planting pattern for improving the yield and WUE of wheat in the NCP. Full article

The atmosphere is a complex nonlinear system, with the information of its temperature, water vapor, pressure, and cloud being crucial aspects of remote-sensing data analysis. There exist intricate interactions among these internal components, such as convection, radiation, and humidity exchange. Atmospheric phenomena span multiple spatial and temporal scales, from small-scale thunderstorms to large-scale events like El Niño. The dynamic interactions across different scales, along with external disturbances to the atmospheric system, such as variations in solar radiation and Earth surface conditions, contribute to the chaotic nature of the atmosphere, making long-term predictions challenging. Grasping the intrinsic chaotic dynamics is essential for advancing atmospheric analysis, which holds profound implications for enhancing meteorological forecasts, mitigating disaster risks, and safeguarding ecological systems. To validate the chaotic nature of the atmosphere, this paper reviewed the definitions and main features of chaotic systems, elucidated the method of phase space reconstruction centered on Takens’ theorem, and categorized the qualitative and quantitative methods for determining the chaotic nature of time series data. Among quantitative methods, the Wolf method is used to calculate the Largest Lyapunov Exponents, while the G–P method is used to calculate the correlation dimensions. A new method named Improved Saturated Correlation Dimension method was proposed to address the subjectivity and noise sensitivity inherent in the traditional G–P method. Subsequently, the Largest Lyapunov Exponents and saturated correlation dimensions were utilized to conduct a quantitative analysis of FY-4A and Himawari-8 remote-sensing infrared observation data, and ERA5 reanalysis data. For both short-term remote-sensing data and long-term reanalysis data, the results showed that more than 99.91% of the regional points have corresponding sequences with positive Largest Lyapunov exponents and all the regional points have correlation dimensions that tended to saturate at values greater than 1 with increasing embedding dimensions, thereby proving that the atmospheric system exhibits chaotic properties on both short and long temporal scales, with extreme sensitivity to initial conditions. This conclusion provided a theoretical foundation for the short-term prediction of atmospheric infrared radiation field variables and the detection of weak, time-sensitive signals in complex atmospheric environments. Full article

In this work, pine and birch wood were modified by graphene oxide using a single vacuum impregnation method. The research results indicate that the impregnation of wood with graphene oxide increases the crystallinity of cellulose in both pine and birch wood, and the increase in crystallinity observed in the case of birch was more significant than in the case of pine. FT-IR analyses of pine samples impregnated with graphene oxide showed changes in intensity in the absorption bands of 400–600, 700–1500 cm⁻¹, and 3200–3500 cm⁻¹ and a peak separation of 1102 cm⁻¹, which may indicate new C-O-C connections. In the case of birch, only some differences were noticed related to the vibrations of the OH group. The proposed modification also affects changes in the color of the wood surface, with earlywood containing more graphene oxide than latewood. Analysis of scanning electron microscope images revealed that graphene oxide adheres flat to the cell wall. Considering the differences in the anatomical structure of both wood species, the research showed a statistically significant difference in water absorption and retention of graphene oxide in wood cells. Graphene oxide does not block the flow of water in the wood, as evidenced by the absorbability of the working liquid at the level of 580–602 kg/m³, which corresponds to the value of pure water absorption by wood in the impregnation method using a single negative pressure. In this case, higher graphene oxide retention values were obtained for pine wood. Full article

Mycelium-bound composites (MBCs) represent a promising advancement in bio-based building materials, offering sustainable alternatives for engineering and construction applications. This review provides a comprehensive overview of the current research landscape, production methodologies, and standardization ideas related to MBCs. A basic search on Scopus revealed over 250 publications on MBCs between 2020 and 2024, with more than 30% focusing on engineering and materials science. Key studies have investigated the physical and mechanical properties of MBCs, optimizing parameters such as substrate type, fungal species, incubation time, and post-processing to enhance material performance. Standardizing the inspection of MBC properties is crucial for ensuring quality and reliability. Various testing standards, including those from the American Society for Testing and Materials (ASTM), the International Organization for Standardization (ISO), the Japanese Industrial Standard (JIS), European Standards (EN), Deutsches Institut für Normung (DIN), and the Thai Industrial Standards Institute (TIS), are utilized to evaluate density, water absorption, compression strength, tensile strength, insulation, and other critical properties. This review highlights the distinction between lab-scale and apply-scale testing methodologies, emphasizing the need for comprehensive evaluation protocols. Additionally, the production process of MBCs involves critical steps like substrate preparation, fungal species selection, and mycelium growth, necessitating the implementation of good manufacturing practices (GMPs) to ensure consistency and quality. The internal and external structures of MBCs significantly influence their performance, necessitating standardized inspection methods using advanced techniques such as scanning electron microscopy (SEM), X-ray computed tomography (CT) scanning, and surface profilometry. By establishing robust inspection protocols and production standards, the industry can enhance the reliability and adoption of MBCs, contributing to innovations in materials science and promoting environmental sustainability. This review underscores the importance of interdisciplinary collaboration, advanced characterization tools, and regulatory frameworks to address challenges and advance the field of MBCs. Full article

In this work, a series of fluorinated microemulsions were synthesized using thermally decomposable N-dodecyl-N,N-dimethylamine N-oxide (LDAO) as surfactant. Then, polybutylene terephthalate nonwoven fabrics (PBT) were coated with microemulsion and heat-treated. Superhydrophobic and oil-repellent modified PBT with WCA (water contact angle) of about 152°, a sliding angle of about 2.1°, and oil repellency grade of 8 were prepared. The effect of surfactants on the surface wettability of hydrophobic materials was analyzed by TG-DTA, XPS, and WCA tests. The results show that surfactants decrease the WCA of hydrophobic materials, but LDAO can eliminate this effect by heat treatment. The anti-corrosion and permeability of LDAO coatings were compared with those of conventional fluorinated coatings through degradation and anti-permeability tests. It was shown that the LDAO fluorinated superhydrophobic coating is more resistant to corrosion by chemical solutions and significantly improves the impermeability of porous materials. Anti-fouling and self-cleaning tests showed excellent anti-fouling and self-cleaning properties on several common substrate surfaces modified with LDAO fluorinated microemulsions. It is expected that these new LDAO fluorinated microemulsions have promising applications in the preparation of corrosion-resistant surfaces and impermeable structures. Full article

Ensuring the protection of the aquatic environment and addressing the water scarcity and degradation of water quality in the Mediterranean region pose significant challenges. This study specifically aims to assess the impact of urban and industrial pollution on the ZAT River water quality. The study exploits a combination of field measurements and mathematical simulations using the PEGASE model. The objective is to evaluate how water quality changes throughout the different seasons and to determine whether olive oil factories discharge industrial wastewater into the river. The study reveals that the river water quality remains relatively stable along its course, up to km 64 in winter and km 71.77 in summer, where poor water quality is recorded. This degradation can be attributed to multiple factors. One of these factors is the discharge of industrial wastewater, which accounts for 47% of the COD pollution load. This industrial wastewater is released into the river without treatment during the production period (January–February) and inactivity period (March–May). The combined impact of urban and industrial wastewater is also associated with the decrease in water flow resulting from water withdrawals due to irrigation canals and groundwater recharge, which both contribute to the observed changes in river water quality. Importantly, field measurements combined with results obtained from the calibrated model provide compelling evidence of unauthorized wastewater discharges from the olive oil factories into the river. These results emphasize the need for stricter regulation, such as developing water quality monitoring strategies based on the use of modeling methodologies. They also emphasize the importance of improving wastewater management practices, such as setting up treatment plants for different sources of pollution or developing a co-treatment plant to mitigate the adverse impact of industrial pollution on river water quality. Full article

Sewage sludge (SS) holds promise for environmental, agricultural, and energy applications. However, its direct use is limited due to contaminant concerns. Pyrolysis can turn SS into beneficial products like bio-oil and biochar. This study explores biochar production from SS pyrolysis and its potential for pollutant adsorption. The effects of pyrolysis temperature (500, 650, 850 °C) and SS particle size (800–1000 µm, 400–800 µm, 100–400 µm, ≤100 µm) on biochar yield and adsorption capacity for methylene blue and mercury were investigated. Regardless of particle size and temperature, SS-derived biochar exhibited second-order adsorption kinetics. Biochar with a particle size of 100–400 µm displayed the highest potential for methylene blue adsorption. Subsequent alkali treatment (biochar:NaOH = 3:4) of these particles significantly increased specific surface area from 27.5 m²/g to 144.27 m²/g and further enhanced adsorption capacities for both methylene blue (from 9 mg/g to 35 mg/g) and mercury (from 17 mg/g to 36 mg/g). These findings suggest that SS-derived biochar, particularly the 100–400 µm fraction with alkali treatment, presents a promising cost-effective adsorbent for water treatment, aligning with circular economy principles. Full article

In this research, considering the air methodology, an axisymmetric model was developed, validated, and calibrated for the numerical simulation of an Oscillating Water Column (OWC) converter subjected to a realistic sea state, representative of the Cassino beach, in the south of Brazil. To do so, the Finite Volume Method (FVM) was used, through the Fluent software (Version 18.1), for the airflow inside the hydro-pneumatic chamber and turbine duct of the OWC. Furthermore, the influence of geometric parameters on the available power of the OWC converter was evaluated through Constructal Design combined with Exhaustive Search. For this, a search space with 100 geometric configurations for the hydro-pneumatic chamber was defined by means of the variation in two degrees of freedom: the ratio between the height and diameter of the hydro-pneumatic chamber (H₁/L₁) and the ratio between the height and diameter of the smallest base of the connection, whose surface of revolution has a trapezoidal shape, between the hydro-pneumatic chamber and the turbine duct (H₂/L₂). The ratio between the height and diameter of the turbine duct (H₃/L₃) was kept constant. The results indicated that the highest available power of the converter was achieved by the lowest values of H₁/L₁ and highest values of H₂/L₂, with the optimal case being obtained by H₁/L₁ = 0.1 and H₂/L₂ = 0.81, achieving a power 839 times greater than the worst case. The values found are impractical in real devices, making it necessary to limit the power of the converters to 500 kW to make this assessment closer to reality; thus, the highest power obtained was 15.5 times greater than that found in the worst case, these values being consistent with other studies developed. As a theoretical recommendation for practical purposes, one can infer that the ratio H₁/L₁ has a greater influence over the OWC’s available power than the ratio H₂/L₂. Full article