Search Results (432,963)

In recent years, a new type of natural gas hydrate reservoir (designated as Class 1S reservoir) has been discovered in the Qiongdongnan Basin. Within this hydrate reservoir, free gas and hydrate coexist within the same stratum. The Class 1S reservoir is comprised of three distinct zones: the gas accumulation zone, the three-phase zone, and the hydrate-bearing zone. It exhibits significant commercial development potential. This paper analyzes the formation mechanism and geological context of Class 1S hydrates. A geological model was established and numerical simulation methods were employed to evaluate its production capacity, elucidating the evolutionary patterns of hydrate saturation distribution at different well locations. The simulation results indicate that production wells should be prioritised in gas accumulation zones in order to achieve the highest cumulative gas production. Additional production wells may be considered in later stages to enhance recovery rates. Secondary hydrate formation significantly impacts production in Hydrate-bearing zone and three-phase zone. Measures such as wellbore heating can be employed to minimize secondary hydrate formation around the wellbore. Full article

The study of the destruction mechanisms of mineral component particles during processing in grinding units is a relevant scientific problem that requires further theoretical and experimental solutions. This work is dedicated to determining the kinetic characteristics of ferromagnetic bodies moving under the influence of an electromagnetic field within a vortex mill. Dependencies of the velocity of these bodies on the radial coordinate for various values of magnetic induction and its gradient were obtained, establishing that velocities can reach approximately 50 m/s. A model for the disintegration of Portland cement particles, caused by their interaction during mechanical processing in a vortex mill, has been developed. It is shown that the average number of disintegration events for the predominant portion of the studied particles is two, which is significantly lower than the total number of collisions. An analysis of the key factors influencing the intensity and nature of particle destruction was conducted, including the magnitude of magnetic induction, the switching frequency of electromagnets, and the magnetic susceptibility of the processed materials. Based on a statistical analysis of the particle size distributions of the mineral raw material after dispersion, a principle for dividing the space within the working volume of the unit into functional zones was formulated: (1) a zone of mixing, grinding, and particle activation (at ferromagnetic element speeds of 0–12 m/s); (2) a zone of intensive grinding and particle activation (with speeds of 12–50 m/s). Full article

This study investigates the influence of suspension elastokinematics on vehicle handling and stability through a combined research of experimental testing and numerical simulation. Laboratory tests were conducted on the front suspension of a Mercedes-Benz S320 using a quarter-car test rig equipped with specialized sensors to measure wheel displacements, steering angles, camber, and accelerations. Complementary dynamic tests were carried out under real driving conditions, including braking in a turn and “fishhook” maneuvers, to capture suspension behavior under critical operating scenarios. Based on the experimental data, an MSC Adams/Car multibody simulation model was used, incorporating varying stiffness values of suspension elastomeric elements that replicated progressive aging and degradation effects. The simulation results were compared with experimental data to validate the model’s predictive capability. Key findings indicate that reductions in elastomer stiffness significantly affect wheel kinematics, vehicle yaw response, and lateral acceleration, particularly during high-intensity maneuvers. The results underline the critical importance of accounting for elastomeric component degradation in suspension modeling to ensure vehicle safety and performance over the operational lifespan. The developed methodology demonstrates the effectiveness of integrating experimental measurements with advanced simulation tools to assess elastokinematic effects on vehicle dynamics. Full article

This paper explores how collective resilience is built and sustained through situated, relational, and reparative approaches to design within conditions of deep spatial inequality. Focusing on Johannesburg’s Slovo Park settlement and the long-standing 15 year collaboration between the Slovo Park Community Development Forum (SPCDF) and 1to1—Agency of Engagement, it examines how participatory tool-making—centred on two keystone tools, the Blue File (a community-held, cloud-based knowledge repository) and the Timeline Tool (a multi-workshop planning and accountability device)—supports iteration, voice change, leadership transitions, and decision-making “with the map in hand.” Grounded in Southern urbanist theory and spatial justice scholarship, the paper re-politicises resilience as ongoing negotiation, repair, and shared authorship. It details how a map-based pointing practice translated situated knowledges into spatial choices; how the Blue File preserved continuity and evidence through leadership turnover; and how the Timeline Tool embedded care and transparency. Alongside benefits, the paper surfaces key tensions—expectation management, idea overload, triage and prioritisation, and legitimacy during leadership changes—and shows the concrete decision protocols used to move from many inputs to buildable design options. It concludes with ethical reflections for practitioners working in postcolonial/post-apartheid contexts and offers transferable lessons for allied urban conditions. Full article

Background: Chronic kidney disease (CKD) requires strict dietary management tailored to disease stage and individual needs. Recent advances in artificial intelligence (AI) have introduced chatbot-based tools capable of generating dietary recommendations. However, their accuracy, personalization, and practical applicability in clinical nutrition remain largely unvalidated, particularly in non-Western settings. Methods: Simulated patient profiles representing each CKD stage were developed and used to prompt GPT-4 (OpenAI), Gemini (Google), and Copilot (Microsoft) with the same request for meal planning. AI-generated diets were evaluated by three physicians using a 5-point Likert scale across three criteria: personalization, consistency with guidelines, practicality, and availability. Descriptive statistics, Kruskal–Wallis tests, and Dunn’s post hoc tests were performed to compare model performance. Nutritional analysis of four meal plans (Initial, GPT-4, Gemini, and Copilot) was conducted using both GPT-4 estimates and manual calculations validated against clinical dietary sources. Results: Scores for personalization and consistency were significantly higher for Gemini and GPT-4 compared with Copilot, with no significant differences between Gemini and GPT-4 (p = 0.0001 and p = 0.0002, respectively). Practicality showed marginal significance, with GPT-4 slightly outperforming Gemini (p = 0.0476). Nutritional component analysis revealed discrepancies between GPT-4’s internal estimations and manual values, with occasional deviations from clinical guidelines, most notably for sodium and potassium, and moderate overestimation for phosphorus. Conclusions: While AI chatbots show promise in delivering dietary guidance for CKD patients, with Gemini demonstrating the strongest performance, further development, clinical validation, and testing with real patient data are needed before AI-driven tools can be fully integrated into patient-centered CKD nutritional care. Full article

With an emphasis on common-mode voltage (CMV) and leakage current suppression, this research offers a thorough examination of three-phase, two-level buck inverter topologies for transformerless (TL) grid-tied photovoltaic (PV) systems. A comprehensive classification and comparative evaluation of modern voltage-source inverter (VSI) and current-source inverter (CSI) topologies, such as H6, H7, H8, H10, and hybrid setups, constitute the paper’s main contribution. The main conclusions show that CSIs naturally offer better leakage current suppression, albeit at the expense of cost and complexity, while sophisticated VSIs (such as specific H8 and H10 topologies) in conjunction with specialized modulation techniques (like modified discontinuous PWM) provide balanced performance. The study finds intriguing research possibilities for further work in this area and indicates that the ideal topology depends on the specific application. Full article

Parkinson’s disease (PD) is a progressive neurodegenerative disorder whose primary manifestation is motor dysfunction. Previous research showed that (1R,2R,6S)-3-methyl-6-(prop-1-en-2-yl)cyclohex-3-ene-1,2-diol (Prottremine) exhibits potent antiparkinsonian activity in animal models of PD, with an efficacy comparable to levodopa. Herein, we report the synthesis of a new Prottremine derivative, (1R,2R,6S)-3-methyl-6-(3-(4-phenylpiperidin-1-yl)prop-1-en-2-yl)cyclohex-3-ene-1,2-diol. The compound was fully characterized and its structure was confirmed through single-crystal X-ray diffraction analysis. Full article

Background: Gut microbiota plays a critical role in host metabolism, immunity, and intestinal barrier integrity. Both chronic kidney disease (CKD) and kidney transplantation (KTR) are associated with gut dysbiosis, driven by uremic toxins, comorbidities, and immunosuppressive therapy. However, direct comparisons between hemodialysis (HD), KTR, and healthy controls (HC), while accounting for dietary factors, remain limited. Methods: We conducted a cross-sectional study including 48 HD patients, 75 KTR patients, and 13 HC. Stool patient samples were analyzed using 16S rRNA amplicon sequencing targeting the V4-V4 region to assess microbial composition and diversity. Data on clinical status, laboratory parameters, and dietary intake were collected and integrated with microbiome profiling. Results: Firmicutes and Bacteroidota dominated all groups, with Akkermansia enriched in HD and SCFA-producing genera (Faecalibacterium, Roseburia) more abundant in KTR. LEfSe and sPLS-DA analyses identified Akkermansia and Clostridia-related taxa as discriminants of HD, while Acidaminococcus and Megasphaera characterized KTR. HD patients exhibited higher alpha diversity (Faith’s PD and Chao1) than KTR (p < 0.05). Dietary intake differed across groups, but explained only a small proportion of microbial variance. Conclusions: Both HD and KTR patients display persistent gut dysbiosis with distinct microbial signatures. While transplantation partially restores SCFA producers, immunosuppression and diet shape new ecological shifts. These findings underscore the potential of microbiota as a biomarker and therapeutic target in renal replacement therapies. Full article

Autonomous driving is anticipated to increase safety, efficiency, and accessibility of passenger transportation. Passengers are given freedom in the use of travel time through the potential to conduct non-driving related tasks (NDRTs). However, factors such as trust and motion sickness pose challenges to the widespread adoption of this technology. Human–machine interfaces (HMIs) have shown potential in mitigating motion sickness and fostering trust calibration in autonomous vehicles (AVs), e.g., by visualizing upcoming or current maneuvers of the vehicle. The majority of research on such HMIs relies on the passengers’ attention, preventing uninterrupted NDRT execution and thus impeding the automation’s usefulness. In this paper, we present a visual HMI, providing AV passengers with information about current driving maneuvers through their peripheral fields of view. This method of information transmission is compared to conventional in-vehicle displays and LED strips regarding perceptibility and distraction. In a controlled laboratory setting, N = 34 participants experienced each HMI condition, indicating their perception of the maneuver visualizations using joystick input while either focusing on a fixation cross to measure perceptibility or solving math tasks to measure distraction. The peripheral HMIs caused better maneuver perception ($\eta p^2=0.12$) and lower distraction ($\eta g^2=0.16$) from a visual NDRT than the conventional displays. These results yield implications for the design of HMIs for motion sickness mitigation and trust calibration in AVs. Full article

The Arctic Puffin Optimization (APO) algorithm, proposed in 2024, is a swarm intelligence optimization. Similar to other swarm intelligence optimization algorithms, it suffers from issues such as slow convergence in the early stage, being easy to fall into local optima, and insufficient balance between exploration and exploitation. To address these limitations, an improved APO (IAPO) algorithm incorporating multiple strategies is proposed. Firstly, a mirror opposition-based learning mechanism is introduced to expand the search scope, improving the efficiency of searching for the optimal solution, which enhances the algorithm’s convergence accuracy and optimization speed. Secondly, a dynamic differential evolution strategy with adaptive parameters is integrated to improve the algorithm’s ability to escape local optima and achieve precise optimization. Comparative experimental results between IAPO and eight other optimization algorithms on 20 benchmark functions, as well as CEC2019 and CEC2022 test functions, show that IAPO achieves higher accuracy, faster convergence, and superior robustness, securing first-place average rankings of 1.35, 1.30, 1.25, and 1.08 on the 20 benchmark functions, CEC 2019, 10- and 20-dimensional CEC 2022 test sets, respectively. Finally, simulation experiments were conducted on three engineering optimization design problems. IAPO achieved optimal values of 5.2559 × 10⁻¹, 1.09 × 10³, and 1.49 × 10⁴ for these engineering problems, ranking first in all cases. This further validates the effectiveness and practicality of the IAPO algorithm. Full article

Land is a limited yet vital resource, which is fundamental for food security and national stability. Ensuring its effective use requires modern tools to support informed decision making. This study evaluates land suitability for irrigation in the Kyzylorda region of Kazakhstan, with the objective of identifying areas appropriate for crop expansion. A multidimensional approach was employed, integrating soil properties, topography, proximity to water sources, and existing land use patterns, with suitability classes defined according to the Food and Agriculture Organization’s framework. The Analytic Hierarchy Process, based on pair-wise comparisons and Saaty’s scale, was used to assign weights to each factor. The findings reveal that 30% of highly suitable land and 80% of suitable land remain uncultivated. Conversely, 10% of the current cropland is located in marginally suitable area—likely a result of historical land use decisions or the limited availability of optimal land. This research responds to the specific challenges of arid climates and water scarcity by providing a decision-support tool that promotes sustainable land use, strengthens food security, and encourages responsible land management. Full article

Türkiye’s forest governance exhibits a persistent policy–implementation gap rooted in a governance paradox: while the Ecosystem-Based Functional Planning (EBFP) system promotes ecological integrity and adaptive management, the foundational Forest Law No. 6831 (1956) still legitimizes extractive uses under a broad “public interest” doctrine. This contradiction has enabled 94,148 permits covering 654,833 ha of forest conversion, while marginalizing nearly seven million forest-dependent villagers from decision-making. The study applies a doctrinal and qualitative document-analysis approach, integrating legal, institutional, and socio-economic dimensions. It employs a comparative design with five EU transition countries—Poland, Romania, Bulgaria, Czechia, and Greece—selected for their shared post-socialist administrative legacies and diverse pathways of forest-governance reform. The analysis synthesizes legal norms, policy instruments, and institutional practices to identify drivers of reform inertia and regulatory capture. Findings reveal three interlinked failures: (1) institutional and ministerial conflicts that entrench centralized decision-making and weaken environmental oversight—illustrated by the fact that only 0.97% of Environmental Impact Assessments receive negative opinions; (2) economic and ecological losses, with foregone ecosystem-service values exceeding EUR 200 million annually and limited access to carbon markets; and (3) participatory deficits and social contestation, exemplified by local forest conflicts such as the Akbelen case. A comparative SWOT analysis indicates that Poland’s confrontational policy reforms triggered EU infringement penalties, Romania’s fragmented legal restitution fostered illegal logging networks, and Greece’s recent modernization offers lessons for gradual legal harmonization. Drawing on these insights, the paper recommends comprehensive Forest Law reform that integrates ecosystem-service valuation, climate adaptation, and transparent participatory mechanisms. Alignment with the EU Nature Restoration Regulation (2024/1991) and Biodiversity Strategy 2030 is proposed as a phased transition pathway for Türkiye’s candidate-country obligations. The study concludes that partial reforms reproduce systemic contradictions: bridging the policy–law divide requires confronting entrenched political-economy dynamics where state actors and extractive-industry interests remain institutionally intertwined. Full article

Introduction: Evaluating cardiovascular function is crucial in the care of critically ill patients. Recent advancements in continuous cardiac output (CO) monitoring have led to the emergence of several arterial pulse contour devices. To effectively compare the accuracy of these devices, a comprehensive assessment is necessary. However, no experimental studies were found that have evaluated these devices in a controlled setting. Methods: In this innovative bench study, we used a Donovan mock circulatory system in conjunction with a total artificial heart (TAH-t) to simultaneously generate several comparable arterial waveforms and compared CO estimates from three different pulse contour devices: FloTrac™ (Vigileo™, v1.8 4th generation, Edwards LifeSciences, Irvine, CA, USA), proAQT™ (PulsioFlex™, Pulsion Medical Systems, Munich, Germany), and LiDCO™ Plus (LiDCO™, LidCO Ltd., Cambridge, UK). These devices underwent several hemodynamic challenges (HCs), including decreased preload, decreased afterload, and increased heart rate. To evaluate the degree of agreement between the devices, we performed a Bland–Altman analysis for the paired devices. The interclass comparison, error percentage, and variation coefficient for each device were also assessed. Results: The present study first tested the comparability between the three additional arterial line waveforms, and the arterial control line was simultaneously generated with the hemodynamic simulation bench. Comparing the reference values of the dP/dt and sAUC pulse pressure, we found no clinically significant difference between the simultaneously generated arterial waveforms. The different pulse contour devices were then each connected to the arterial lines, with the performance of HCs. HC1 with a decreased preload revealed that CO estimates significantly decreased compared to the baseline values: 3.2 ± 0.06 L.min⁻¹, 4.7 ± 0.05, 4.3 ± 0.07, and 4.0 ± 0.05 for reference methods FloTrac™, PulsioFlex™, and LiDCO™, respectively. HC2 with an increased heart rate revealed CO estimates with FloTrac™, PulsioFlex™, and LiDCO™—6.0 ± 0.03, 6.6 ± 0.06, and 6.0 ± 0.05 L.min⁻¹, respectively—when the CO estimate was 5.6 ± 0.2. HC3 with a decreased afterload that significantly increased CO estimates compared to the baseline with FloTrac™, PulsioFlex™, and LiDCO™—7.0 ± 0.18, 6.6 ± 0.15, and 7.1 ± 0.30 L.min⁻¹, respectively—when the CO estimate with the reference method did not change significantly (from 5.90 ± 0.13 to 5.94 ± 0.11 p = 0.26). The devices’ degree of agreement was estimated with Bland–Altman analysis. Conclusions: The Donovan Mock Circulatory System with SynCardia TAH-t can be used as an innovative experimental hemodynamic simulation bench. It was proven to be stable, accurate, and reliable in generating several controlled pulse pressure waveforms, while many parameters could be changed, such as the preload, heart rate, or afterload. This enables a simultaneous evaluation of different pulse contour devices submitted to several HCs. This is of interest for clinicians to better understand the underlying principles and realistically compare the performance and potentially inherent limitations of pulse contour devices experimentally in a controlled simulated environment. Full article

Spain’s olive oil production is world-leading. A significant portion of Spain’s olive oil production is in Andalusia, a southern region. In the Estepa region, a local agri-food system based on olive monoculture is emerging. Furthermore, producers are implementing strategies for differential quality and environmental sustainability to increase the competitiveness of their products. One of the main challenges facing the agricultural sector is generational change. The primary objective of this study is to analyze the results of the actions implemented to enhance the organization, sustainability, quality of production, and prices. The aim is to contrast, through a case study, the qualitative aspects that have enabled them to improve their product price through a competitiveness strategy based on quality improvement, which required synergistic actions in terms of productive structuring and sustainability. To this end, this study conducted structured interviews with key stakeholders in the PDO and consulted the National Reference Price Index at Origin. The results show that the pricing system based on olive oil quality has resulted in producers obtaining a differential income of €200/t in the market. However, it has been unable to halt the structural rural exodus and the progressive abandonment of productive agricultural activities. The study offers recommendations for rural development policymakers. Research into new models of production and organization for rural areas that offer social and environmental sustainability is vital, as these models have great relevance for political decision-making. Full article

Intestinal dysbiosis has been linked to metabolic disorders, including insulin resistance and type 2 diabetes mellitus (T2DM). T2DM typically follows a prediabetic stage, during which insulin resistance develops. During the early stages of T2DM, its development can be corrected, thus potentially preventing or delaying the onset of the disease. This secondary, exploratory, cross-sectional comparison study aimed to contrast the gut microbiome of individuals with elevated fasting blood glucose to that of individuals with glucose levels within the normal range. This study involved 65 older adults (ages 76–83 years) enrolled from the randomized controlled trial entitled the “Generation 100 Study”, all of whom consented to provide their gut microbiome samples. We employed a high-throughput sequencing of the bacterial 16S rRNA gene to obtain metagenomic microbial profiles for all participants. These profiles were then correlated with clinical measures. Overall, microbial alpha diversity was significantly reduced in the high glucose group. We have also observed distinct patterns of microbial beta diversity between high and normal glucose groups. At the phylum level, we found that Synergistes, Elusimicobia, Euryarchaeota, Verrucomicrobia, and Proteobacteria were all significantly decreased in participants with high blood glucose. Additionally, P. copri (ASV 909561) was significantly elevated (10-fold increase) in the high glucose groups, suggesting that it may serve as an early T2DM marker. In contrast to prior reports on the Fusobacterium genus, we found that it was significantly increased in the normal glucose group, with a significant 151-fold increase compared to the high glucose group. Directly linking gut microbiota profiles with clinical indicators such as fasting blood glucose and T2DM diagnosis allows the identification of specific microbial features associated with glucose dysregulation, providing preliminary population-level evidence to guide future translational research. Our results indicate significant changes in the microbiome that may provide valuable insights for early intervention in pre-diabetic states. Full article