Search Results (2,281)

Pipeline systems are essential across various industries for transporting fluids over various ranges of distances. A notable application is natural circulation through thermo-syphoning, driven by temperature-induced density variations that generate fluid flow in closed loops. This passive mechanism is widely employed in sectors such as process engineering, oil and gas, geothermal energy, solar water heaters, fertilizers, etc. Natural Circulation Loops eliminate the need for mechanical pumps. While this passive mechanism reduces energy consumption and maintenance costs, maintaining stability and efficiency under varying operating conditions remains a challenge. This study investigates thermo-syphoning in a rectangular closed-loop system and develops optimal control strategies like using a Linear Quadratic Regulator (LQR) and Model Predictive Control (MPC) to ensure stable and efficient heat removal while explicitly addressing physical constraints. The results demonstrate that MPC improves system stability and reduces energy usage through optimized control actions by nearly one-third in the initial energy requirement. Compared to the LQR and unconstrained MPC, MPC with active constraints effectively manages input limitations, ensuring safer and more practical operation. With its predictive capability and adaptability, the proposed MPC framework offers a robust, scalable solution for real-time industrial applications, supporting the development of sustainable and adaptive natural circulation pipeline systems. Full article

Learning Natural Sciences represents a key opportunity to spark scientific interest and foster fundamental skills across different educational stages. This study aimed to analyze the influence of motivation on academic performance in the learning of Natural Sciences at various educational levels. To this end, a systematic review method was employed following PRISMA guidelines, consulting the Web of Science and Scopus databases, identifying four relevant studies. The results showed that high levels of motivation were associated with a more positive classroom attitude and better conceptual understanding, which enhanced academic performance. The use of innovative methodological strategies, such as implementing immersive virtual reality in the classroom, PhET simulations (Physics Educational Technology), and the use of hypertext, significantly increased both student motivation and academic performance. The meta-analysis revealed a favorable effect in experimental groups, showing moderate heterogeneity (I² = 49) and significance of p = 0.0001. The concurrence analysis reported that current pedagogical practices should focus on strengthening student autonomy and active engagement, integrating critical reflection, the use of innovative methodological strategies, and technological resources that enhance meaningful learning in scientific literacy. Among the instruments used to measure motivation, the Motivation to Learn Science Questionnaire was identified, and for academic performance, the Motivated Strategies for Learning Questionnaire. In conclusion, the importance of implementing the identified methodological strategies across different educational stages is emphasized, in order to promote competency-based learning through meaningful and innovative acquisition of content in Natural Sciences. Full article

The pursuit of a comprehensive understanding of human consciousness, which includes the subjective experience of perception, is a long-standing endeavor. A multitude of disciplines have sought to elucidate and define consciousness, with a particular emphasis on its etiology. What is the cause of consciousness? One particularly eye-opening idea is that humans attempt to identify the source of consciousness by leveraging their own consciousness, as if something is attempting to elucidate itself. Strikingly, the results of brain-imaging experiments indicate that the brain processes a considerable amount of information outside conscious awareness of the organism in question. Perhaps, the vast majority of decision making, thinking, and planning processes originate from non-conscious brain processes. Nevertheless, consciousness is a fascinating phenomenon, and its intrinsic nature is both intriguing and challenging to ascertain. In the end, it is not necessarily given that consciousness, in particular the phenomenon of perception as the subjective experience it is, is a tangible function or process in the first place. This is why it must be acknowledged that this theoretical paper is not in a position to offer a definitive solution. However, it does present an interesting new concept that may at least assist future research and potential investigations in achieving a greater degree of elucidation. The concept is founded upon a physical (mathematical) phenomenon known as stochastic resonance. Without delving into the specifics, it is relatively straightforward to grasp one of its implications, which is employed here to introduce a novel direction regarding the potential for non-conscious information within the human brain to become conscious through the introduction of noise. It is noteworthy that this phenomenon can be visualized through a relatively simple approach that is provided in the frame of this paper. It is demonstrated that a completely white image is transformed into an image depicting clearly recognizable content by the introduction of noise. Similarly, information in the human brain that is processed below the threshold of consciousness could become conscious within a neural network by the introduction of noise. Thereby, the noise (neurophysiological energy) could originate from one or more of the well-known activating neural networks, with their nuclei being located in the brainstem and their axons connecting to various cortical regions. Even though stochastic resonance has already been introduced to neuroscience, the innovative nature of this paper is a formal introduction of this concept within the framework of consciousness, including higher-order perception phenomena. As such, it may assist in exploring novel avenues in the search for the origins of consciousness and perception in particular. Full article

Background/Objectives: The 24 h activity cycle highlights the need to consider sedentary behavior (SED), non-exercise physical activity (NEPA), and sleep when introducing aerobic exercise. This study assessed changes in these components among breast cancer survivors (BCS) and non-oncologic menopausal women after a 3-month walking (W) or Nordic walking (NW) program. Methods: A total of 324 menopausal women participated: 156 non-oncologic (Meno), 102 BCS with natural menopause (BCS_Meno), and 66 BCS with medically induced menopause (BCS_Ind_Meno). Linear Mixed Effects (LME) modeling was applied. Age, BMI, hormonal therapy, cancer treatments, hypertension, sleep, and METs were included as covariates. Results: BCS_Meno and BCS_Ind_Meno had longer sleep durations at baseline (adj. diff.: +26.5 min/day, 95% CI 10.1 to 43.0; p = 0.002 and +25.7, 95% CI 6.7 to 44.6; p = 0.008). Sleep improved across all groups post-intervention (overall adj. effect = +17.4 min/day, 95% CI 4.8 to 30.0; p = 0.007). Higher sleep and METs were associated with reduced SED (sleep: β = −43.7 min/day per unit increase, −52.6 to −34.8; METs: β = −115.4, −126.4 to −104.4; both p < 0.001). A significant group × time interaction showed a decrease in SED in the BCS_Ind_Meno group (adj. diff. = −65.1 min/day, −102.8 to −27.4; p = 0.001). NEPA was negatively influenced by sleep (β = −8.7 min/day, −16.2 to −1.1, p = 0.024) and positively by METs (β = +121.1, 111.8 to 130.3; p < 0.001). NEPA increased only in BCS_Ind_Meno (adj. diff.: +70.6 min/day, 38.4 to 102.7; p < 0.001), not in BCS_Meno (+9.87, −18.7 to 38.4; p = 0.497). Conclusions: BCS_Ind_Meno showed the greatest benefits, with reduced SED, increased NEPA, and improved sleep. Sleep improved across all groups following aerobic interventions. Full article

Hydrogels are hydrophilic biocompatible polymers that can be used as a drug delivery material in different medical branches, including vital pulp therapy. The aim of this study is to characterize the physical and biological properties of the newly developed formula as a candidate direct pulp-capping material. The hydrogel composite was prepared from natural and synthetic origins (polyvinyl alcohol (PVA), hyaluronic acid (HA), and sodium alginate (SA)) with the incorporation of bioactive Moringa. Different formulas of hydrogel containing different concentrations were evaluated for physicochemical (FTIR, XRD, SEM, degradation, and swelling), mechanical (viscosity, folding endurance, film thickness), and biological (antioxidant, antibacterial, and cytotoxicity) properties. FTIR and XRD confirmed successful incorporation and partial cross-linking between moringa and hydrogel compounds. At low concentrations of moringa, the hydrogel formula showed integrity, scavenging activity, and homogeneity. The moringa-loaded films showed concentration-dependent antioxidant and antibacterial properties, especially at higher concentrations, with acceptable cytocompatibility. The low concentration of moringa (0.5%) may be considered a promising candidate as a novel pulp-capping agent supporting tissue healing and regeneration. Full article

Background: University students are particularly vulnerable to psychological distress due to the transitional nature of this life phase and increasing academic, social, and financial pressures. Accumulating evidence indicates that lifestyle behaviors—especially nutrition and physical activity—play a critical role in shaping mental health, cognitive functioning, and overall well-being in this population. Methods: The objective of this scoping review was to systematically map the literature on the combined impacts of diet and physical activity on psychological well-being among university students. Following PRISMA-ScR guidelines, an initial search of three major databases (PubMed, Sciencedirect, and Wiley) yielded 718 articles. After a multi-stage screening process, 39 articles of various designs (including cross-sectional, interventional, and review studies) focusing on non-clinical student populations were included. The studies were then thematically analyzed. Results: While most research explored isolated behaviors, a smaller set of integrated studies revealed synergistic effects, reporting enhanced outcomes in mental health and quality of life. Notably, several articles proposed practical strategies—such as app-based tools, structured wellness initiatives, and interdisciplinary educational programs—as effective means to support healthier habits. Conclusions: The evidence strongly suggests that universities should prioritize holistic, multi-component wellness strategies over siloed, single-behavior initiatives. Developing integrated programs that combine nutritional education and physical activity support represents a practical and effective approach to enhance student well-being. Full article

In the present study three composite materials based on iron in combination with bismuth, copper or lithium carbonates FeNO₃@Li₂CO₃ (SFL), FeNO₃@CuCO₃ (SFC), and FeNO₃@(BiO)₂CO₃ (SFB) were synthesized by coprecipitation. The purpose was to obtain materials that possess targeted adsorbent properties for the recovery of silver ions from aqueous solutions. After synthesis, to emphasize the adsorptive qualities of materials for the recovery of silver ions, the synthesized composite materials, as well as those doped with silver ions following the adsorption process (SFL-Ag, SFC-Ag, and SFB-Ag), were characterized and several adsorption-specific parameters were examined, including temperature, contact time, pH, adsorbent dose, and the initial concentration of silver ions in solution. Subsequently, the ideal adsorption conditions were determined to be as follows: pH > 4, contact time 60 min, temperature 298 K, and solid–liquid ratio (S–L) of 0.1 g of adsorbent to 25 mL of Ag (I) solution for all three materials. The Langmuir model properly fits the experimental equilibrium data of the adsorption process; however, the Ho–McKay model closely represents the adsorption kinetics. The maximum adsorption capacities of the materials, 19.7 mg Ag(I)/g for SFC, 19.3 mg Ag(I)/g for SFB, and 19.9 mg Ag(I)/g for SFL, are comparable. The adsorption mechanism is physical in nature, as evidenced by the activation energies of 1.6 kJ/mol for SFC, 4.15 kJ/mol for SFB, and 1.32 kJ/mol for SFL. The highest Ag(I) concentration used for doping all three materials in the study was 150 mg Ag(I)/L. The process is endothermic, spontaneous, and takes place at the interface between the adsorbent and the adsorbate, according to thermodynamic theory. Subsequently, the antimicrobial activity against Staphylococcus aureus, Escherichia coli, Pseudomonas aeruginosa, and Candida albicans microorganisms was evaluated by rate of inhibition assessment. The SFC-Ag material showed a percentage of 100% inhibition with respect to the positive control for each microorganism. All synthetized materials have better efficiency as antifungal agents. Full article

This study explores innovative approaches for sustainable food preservation by incorporating Sichuan pepper extract into biodegradable gelatin and alginate films. In response to growing environmental and health concerns, these natural polymers offer alternatives to petroleum-based plastics and synthetic additives. The aim of this study was to compare films made from gelatin and alginate and containing Sichuan pepper extract (2.5 and 5%) and to evaluate their effectiveness in extending the shelf life of refrigerated beef patties. Scavenging activity and polyphenol content of the extract were evaluated by DPPH (4.70 µmol TE/mL), ABTS (4.03 µmol TE/mL), and Folin–Ciocalteu assays (2.35 mg GAE/mL). In addition, the physical characteristics of the films were also assessed. Film characterization showed that gelatin-based films had greater stiffness (water-based alginate film; 1156 MPa), which diminished with increased extract content (5% extract-based alginate film: 215.5 MPa), and surface homogeneity also declined with higher extract content. However, higher concentrations of the extract (5%) improved optical properties such as UV protection and opacity. Preservation tests performed on beef patties revealed that the films with the extract could significantly reduce lipid oxidation, with lower TBARS values observed in samples covered with these films. Nevertheless, no significant differences were detected between films with the extract. Moreover, samples without the extract were the most oxidized, proving that the film without the extract had no protective effect against oxidation. Overall, these findings underscore the potential of Sichuan pepper as a natural ingredient and highlight the promise of biodegradable films as an effective and eco-friendly strategy for meat product packaging. Full article

Motor skills in students can be developed or improved through regular physical activity such as walking in nature, Nordic walking, hiking, cycling and swimming. This study aimed to examine the relationship between motor skills and various anthropometric and health-related factors, and to appraise any differences in motor performance and body mass index (BMI) on a sample of university students from Croatia. A total of 122 students (73 of them in health programs and 49 in non-health programs) aged 18 to 44 years participated in the study. Motor abilities were evaluated using standardized motor tests, while body composition was assessed via bioelectrical impedance analysis, which measured fat tissue, muscle and bone mass, metabolic age, degree of obesity, total body water, and BMI. While the groups were similar in terms of BMI and weight, students in non-health-related study programs had significantly higher values across a wide array of detailed body composition measures, particularly related to fat and muscle mass. Significant negative correlations were observed between body fat percentage and trunk lift performance (r = −0.55, p < 0.01), as well as between metabolic age and trunk lift performance (r = −0.44, p < 0.01) in health students. In non-health students, the strongest negative correlation was found between body fat percentage and flexibility (r = −0.47, p < 0.01). Higher muscle mass was a positive predictor of motor performance while higher fat mass and metabolic age were significant negative predictors. These findings underscore the impact of body composition on motor performance, particularly strength and flexibility, and highlight the need for targeted preventive strategies among university students. The study supports the implementation of early interventions promoting physical activity and healthy body composition to preserve motor abilities and long-term functional health in this critical age group—especially since lifestyle habits formed during university years tend to persist into adulthood. Full article

Enzymatic browning (EB) is a physiological alteration that compromises the sensory and commercial quality of tree nuts, significantly reducing their market value and functional compound content. Due to its complexity and economic impact, this review compiles updated information on mechanisms and factors driving EB in tree nut species, as well as strategies for its prevention. The EB in tree nuts results from the oxidation of phenolic compounds (PCs) to brown pigments. This process is driven by enzymatic activity such as polyphenol oxidase (PPO), peroxidase (POD), and phenylalanine ammonium lyase (PAL) and strongly enhanced by cellular stress and associated regulation of gene expression. The EB has been documented in several tree nut species, including almonds, betel nuts, chestnuts, hazelnuts, macadamias, pecans, pistachios, and walnuts. This alteration developed both pre-harvest and post-harvest and was influenced by agronomic factors (such as cultivar, nutritional status, climatic conditions, and altitude) and handling (including shelling, storage, and processing). Mitigation strategies include the use of synthetic inhibitors, physical treatments, and the use of plant extracts rich in natural antioxidants, the latter perceived as more sustainable and safer alternatives. Full article

In this study, polysaccharide xanthan gum (XG), used in the oil and gas industry as a thickening agent, was evaluated as an active anti-corrosion component against sweet corrosion at high temperatures and pressures in a saline environment for N80 carbon steel in the oil and gas industry. The evaluation involved measuring weight loss and conducting electrochemical assessments at 5 bar CO₂ partial pressure, different temperatures (e.g., 30 °C and 90 °C), and immersion times (up to 72 h). The electrochemical results indicated that XG effectively mitigated CO₂ corrosion at both low and high temperatures, demonstrating inhibition efficiencies of 70.10% at 30 °C and 61.41% at 90 °C using 1.0 g L⁻¹ of XG, after 24 h. The good inhibition efficiency observed even at high temperatures is likely due to the denaturation process that XG undergoes at high temperatures, where a rigid double-stranded helical structure transitions into two single-stranded, more flexible, worm-like macromolecular conformations. This increases the number and mobility of XG macromolecules available for adsorption on the metal surface. EIS measurements have shown that XG was capable of protecting the metal surface even after prolonged exposure. Potentiodynamic measurements indicated that the inhibitive action of XG is of a mixed type. The Temkin adsorption isotherm model provided a good fit for the observed data, and the calculated parameters suggested that the adsorption of XG primarily occurred through physical adsorption processes, with a contribution from chemical processes. The associated activation energy and the heat of adsorption further supported the physical nature of XG’s adsorption. FTIR analysis was employed to elucidate the interaction between the XG and the N80 carbon steel surface, while SEM-EDS analysis provided visual confirmation of the XG’s impact on the metal surface. Full article

Background/Objectives: Vitamin D (VD) is a fat-soluble vitamin essential for bone health, and calcium and phosphorus absorption. Recently, new interesting functions are reported such as neuroprotective activity, regulatory roles in the immune system, and protective effects in cancer patients. However, the lipophilic nature of VD represents a limitation, as it is associated with low solubility and poor absorption; additionally, VD exhibits poor stability. Methods: Two nanoliposomes containing VD, conventional (LP-VD) and conjugated with D-α-tocopheryl polyethylene glycol 1000 succinate (TPGS, LPT-VD), were developed. The physical and chemical stability during the storage and gastrointestinal stability, the dissolution profile, the cytotoxicity and the Caco-2 cellular uptake were investigated. Nanoliposomes were fully characterized determining sizes, PdI, Zeta potential, encapsulation efficiency and recovery and they were lyophilized to improve stability. Subsequently, the freeze-dried liposomes were encapsulated in hard gelatin capsules to mimic an oral dosage form, and they were subjected to dissolution test. Results: LP-VD exhibited an average size of 85.50 ± 5.70 nm, a PdI of 0.24 ± 0.06, and a ZP of −20.90 ± 4.37 mV. LPT-VD showed an average size of 61.70 ± 3.90 nm, a PdI of 0.26 ± 0.02, and a ZP of −9.45 ± 2.99 mV. The EE% values were 95.76 ± 1.26% and 97.54 ± 3.24% for LP-VD and LPT-VD, respectively. Both nanoliposomes solubilized 2 mg/mL of VD and improved both its storage stability and stability in aqueous and gastrointestinal environment. The freeze-dried products guarantee constant chemical-physical parameters for 28 days at 25 °C. VD dissolution profile was improved. Conclusions: Nanoliposomes, in particular LPT-VD, showed the best results in terms of chemical stability, dissolution profile, and Caco-2 cellular uptake, confirming the stabilization, bioenhancer properties and P-gp inhibition capabilities of TPGS. Full article

This study developed antimicrobial composite coatings from gelatin (GL) and carboxymethyl chitosan (CMCS) functionalized with carvacrol (CA) as a natural alternative for the preservation of strawberries. Films incorporated with 0%, 1.5%, and 3% CA were characterized by their physical, mechanical, and structural properties. The addition of CA significantly improved opacity, tensile strength, elongation-at-break, and thickness, while reducing water vapor permeability, moisture content, and solubility (p < 0.05). Spectroscopy and microscopy also confirmed CA’s uniform dispersion within the matrix. During 14 days of storage at 4 °C, strawberries coated with GL/CMCS/CA-3% significantly reduced weight loss (50.91%) and fungal contamination, improved firmness (79.31%), and maintained color and pH. Conversely, uncoated strawberries showed rapid declines in soluble solids, acidity, phenolics, anthocyanins, vitamin C, and antioxidant activity (p < 0.05). Microbial growth was effectively suppressed in coated fruits, while sensory profiles were drastically impaired in uncoated samples at the end of storage (p < 0.05). These results demonstrate that GL/CMCS/CA coatings can effectively preserve strawberry quality and extend shelf life without synthetic preservatives. Full article

This study reviews the role of Child-Friendly Green Spaces (CFGS) in supporting children’s psychological, physical, and educational recovery following natural disasters. The main research question guiding this review is the following: how do CFGS contribute to holistic child well-being and resilience in disaster-affected contexts, and what barriers and strategies influence their effective integration into recovery frameworks? Employing a rigorous literature review methodology, we synthesized interdisciplinary evidence from environmental psychology, urban planning, public health, and education, encompassing studies published between 2000 and 2024. Findings demonstrate that CFGS significantly reduce trauma-related symptoms such as anxiety, depression, and post-traumatic stress, promotes physical health through active play, and foster educational engagement by improving concentration, attendance, and informal learning opportunities. Furthermore, CFGS contribute directly to multiple Sustainable Development Goals, particularly SDG 3 (Good Health and Well-being), SDG 4 (Quality Education), and SDG 11 (Sustainable Cities and Communities). Despite these advantages, CFGS are often overlooked in formal disaster recovery planning due to prioritization of immediate relief, financial and logistical challenges, and socio-cultural factors. To address these challenges, this study proposes a participatory, culturally sensitive framework for CFGS implementation, which integrates inclusive design, multi-sector collaboration, and ongoing monitoring and evaluation. Grounded in theoretical perspectives such as the Biophilia Hypothesis, Bronfenbrenner’s Ecological Systems Theory, and restorative environments, CFGS are reframed as critical infrastructures for children’s holistic recovery and resilience. The findings underscore the urgent need to embed CFGS within disaster recovery and urban planning policies to promote child-centered, sustainable community development. Full article

Background: Juvenile fibromyalgia (JFM) is a chronic pain disorder characterised by widespread musculoskeletal pain, functional impairment, fatigue, and mood disturbances. Treatment remains challenging, considering the multifactorial nature of the condition and the limited high-quality evidence supporting pharmacological or non-pharmacological interventions. Objectives: This review aimed to critically appraise level I evidence from randomised controlled trials assessing the efficacy and safety of pharmacological and non-pharmacological treatments for adolescents with JFM. Methods: Seven published peer-reviewed clinical trials were examined, including studies investigating duloxetine, milnacipran, pregabalin, cognitive-behavioural therapy (CBT), and the integrated Fibromyalgia Integrative Training Teens (FIT) program, which combines CBT with neuromuscular training. Outcomes of interest included pain intensity, functional disability, depression symptoms, physical activity, and adverse events. Results: Pharmacological agents such as duloxetine, milnacipran, and pregabalin demonstrated modest improvements in pain, but failed to produce consistent benefits in function or mood, and were associated with a high incidence of adverse effects. CBT significantly improved functional disability and depression symptoms, yet it had a limited impact on pain reduction or objectively measured activity levels. The FIT Teens program showed superior outcomes in pain intensity and biomechanical function compared to CBT alone, suggesting a synergistic effect of combining psychological and physical reconditioning strategies. Conclusions: Current evidence supports the use of multimodal treatment approaches in JFM. Non-pharmacological interventions, particularly when integrated with structured exercise, offer meaningful benefits with minimal safety concerns. Larger, methodologically rigorous trials are needed to establish optimal treatment pathways and long-term outcomes for this complex and underserved paediatric population. Full article