Search Results (407,892)

This study proposes a hardware-based approach to address agricultural water shortages by directly improving water supply operations, rather than estimating agricultural water demand or supply. Unlike previous studies that focus on evaluating water supply capacity or predicting reservoir inflows through modeling or data-driven methods, this work proposes an operational strategy involving the physical interconnection of reservoirs. Specifically, the study investigates the coordinated use of surplus storage capacity from reservoirs with high watershed ratios to support those with low watershed ratios, thereby enhancing overall water supply reliability. Reservoir inflows were estimated using the Hydrological Operation Model for Water Resources Systems (HOMWRS). The analysis was conducted on reservoirs managed by the Korea Rural Community Corporation (KRC), selected based on data accessibility and availability. Full article

Inflammatory bowel disease (IBD) is a chronic, heterogeneous condition characterized by recurrent intestinal inflammation and sustained mucosal barrier damage, profoundly impairing patients’ quality of life and imposing a considerable socioeconomic burden. Current therapeutic options are often constrained by low oral bioavailability, pronounced systemic toxicity, and inadequate tissue specificity, limiting their ability to achieve precise and durable efficacy. In recent years, membrane vesicle-based drug delivery systems (MV-DDSs) have shown considerable promise for precision IBD therapy owing to their excellent biocompatibility, mucosal barrier-penetrating capacity, and low immunogenicity. Building upon a systematic discussion of the roles of MV-DDSs in suppressing inflammatory signaling, modulating oxidative stress, preserving barrier integrity, reshaping the gut microbiota, and regulating programmed cell death, this review further compares the differences in key molecular targets and functional outcomes among vesicles of diverse origins and carrying distinct therapeutic payloads. These insights provide a comprehensive strategic reference and theoretical foundation for the rational design, mechanistic optimization, and clinical translation of MV-DDSs in IBD therapy. Full article

With the rapid development of hydrogen fuel cell vehicles, the research on the throttling effect of high-pressure hydrogen is crucial to the safety of hydrogen circulation systems for fuel cells. This paper studies the Joule-Thomson coefficients (${\mathsf{\mu }}_{\mathrm{J}\mathrm{T}}$) of ten gas state equations. The four equations, Van Der Waals (VDW), Redlich-Kwong (RK), Soave-Redlich-Kwong (SRK), and Beattie Bridgeman (BB), were selected for calculation. These were compared with the database of the National Institute of Standards and Technology (NIST), aiming to determine the optimal state equation under different temperature and pressure conditions. The empirical formula of the ${\mathsf{\mu }}_{\mathrm{J}\mathrm{T}}$ pressure and temperature was compounded, and the temperature rise effect was further calculated using the empirical formula of compounding. The results show that the calculated value of ${\mathsf{\mu }}_{\mathrm{J}\mathrm{T}}$ by using the VDW equation in the low-pressure range (0–2 MPa) is closer to the value in the NIST database with an error less than 0.056 $\mathrm{K}\bullet {\mathrm{M}\mathrm{P}\mathrm{a}}^{-1}$. The tendency of ${\mathsf{\mu }}_{\mathrm{J}\mathrm{T}}$ described by the RK equation corresponds to the NIST database; meanwhile, the maximum error in the SRK equation is 0.143916 $\mathrm{K}\bullet {\mathrm{M}\mathrm{P}\mathrm{a}}^{-1}$. The BB equation is more applicable within the pressure range of 20 to 50 MPa with a maximum error of 0.042853 $\mathrm{K}\bullet {\mathrm{M}\mathrm{P}\mathrm{a}}^{-1}$. The fitting error of the empirical formula is within 9.52%, and the relative error of the calculated temperature rise is less than 4%. This research might provide several technical ideas for the study of the throttling effect of hydrogen refueling stations and the hydrogen circulation system of on-board hydrogen fuel cells. Full article

The multi-wing centrifugal fan is an important part of air conditioning systems, particularly in the automotive domain. Due to the compact structure and short blade passage of the fan, it may reduce the aerodynamic performance and generate noise. As a key part of the multi-wing centrifugal fan, the volute tongue has an important impact on the aerodynamic performance and noise of the multi-wing centrifugal fan. In this paper, the volute tongue of a multi-wing centrifugal fan is modified for air conditioning systems, and a novel gradient-radius volute tongue is designed. Specifically, a simulation calculation model for the multi-wing centrifugal fan is developed based on the Realizable $k-\epsilon$ turbulence model and the Ffowcs Williams–Hawkings (FW-H) equation. The simulation results are analyzed, and the reliability of the proposed method is assessed by comparing the total pressure efficiency and noise levels with the corresponding experimental measurements. Subsequently, the aerodynamic performance and noise characteristics of the gradient-radius volute tongue are investigated, with particular attention given to variations in the flow field, pressure pulsation, and noise before and after the modification. The results indicate that the gradient-radius volute tongue effectively attenuates the pressure pulsations arising from the interaction between the volute and the airflow, thereby reducing the tongue-region noise. Compared with the original fan, a noise reduction of 3.5 dB is achieved through the implementation of the gradient-radius volute tongue. Full article

With a high proportion of renewable energy sources connected to the distribution network, traditional optimal power flow (OPF) methods face significant challenges including multi-objective co-optimization and dynamic scenario adaptation. This paper proposes a dynamic optimization framework based on the Dynamic Gravitational Search Algorithm (DynaG) for a multi-energy complementary distribution network incorporating wind power, photovoltaic, and energy storage systems. A multi-scenario OPF model is developed considering the time-varying characteristics of wind and solar penetration (low/medium/high), seasonal load variations, and demand response participation. The model aims to minimize both network loss and operational costs, while simultaneously optimizing power supply capability indicators such as power transfer rates and capacity-to-load ratios. Key enhancements to DynaG algorithm include the following: (1) an adaptive gravitational constant adjustment strategy to balance global exploration and local exploitation; (2) an inertial mass updating mechanism constrained to improve convergence for high-dimensional decision variables; and (3) integration of chaotic initialization and dynamic neighborhood search to enhance solution diversity under complex constraints. Validation using the IEEE 33-bus system demonstrates that under 30% penetration scenarios, the proposed DynaG algorithm reduces capacity ratio volatility by 3.37% and network losses by 1.91% compared to non-dominated sorting genetic algorithm III (NSGA-III), multi-objective particle swarm optimization (MOPSO), multi-objective atomic orbital search algorithm (MOAOS), and multi-objective gravitational search algorithm (MOGSA). These results show the algorithm’s robustness against renewable fluctuations and its potential for enhancing the resilience and operational efficiency of high-penetration renewable energy distribution networks. Full article

Background: Obesity is a multisystemic health problem causing chronic diseases like diabetes or cardiovascular diseases, but also reproductive dysfunctions like infertility in adults or altered puberty onset in children. Exercise is a recognized intervention to control or prevent energy imbalance, thus deeply contributing to metabolic health in physiological and pathological conditions. The kisspeptin system (KS), the main gatekeeper of reproduction and puberty onset in mammals, is also an upcoming “metabolic sensor”, linking energy homeostasis to reproductive ability both centrally and peripherally. Objectives: This narrative review aims at summarizing recent evidence from animal models and human studies on the role of the KS in energy homeostasis, with a focus on the upcoming role of the KS as a metabolic sensor able to modulate the functionality of the hypothalamus–pituitary–gonad axis in males as an adaptive response to exercise. Methods: PubMed and Scopus search (date: 2015–2025; keywords: kisspeptin and metabolism, male reproduction or exercise; kisspeptin and doping). Results and Conclusions: This review article illustrates the crucial role of the KS in linking energy homeostasis and male reproduction at the central and peripheral levels, and modulation of the KS by exercise in physiological and pathological conditions. Due to the large amount of data from animal models, knowledge gaps occur in the analysis of the relationship among KS, energy homeostasis, male reproduction and exercise in humans, particularly in the case of overtraining. Lastly, kisspeptin inclusion in the doping list is also discussed. Full article

Background: Inflammation and nutritional status are known to affect outcomes in patients with chronic obstructive pulmonary disease (COPD). However, their prognostic relevance in critically ill COPD patients remains unclear. This study investigated whether C-reactive protein (CRP), serum albumin, and the CRP/albumin ratio (CAR) were associated with in-hospital mortality in ICU patients with COPD. Methods: We conducted a retrospective cohort study using data from the MIMIC-IV database. Adult ICU patients with a diagnosis of COPD were included. We analyzed CRP, albumin, CAR, glucose, lactate, and creatinine. The primary outcome was in-hospital mortality. Multivariable logistic regression was used to identify variables that were independently associated with in-hospital mortality. Subgroup analyses stratified by age and sex were performed. Results: We included 1000 ICU patients with COPD. In-hospital mortality was 19.6%. In univariate analyses, glucose, creatinine, and lactate levels were significantly higher in non-survivors. In multivariable models, only elevated creatinine (OR 1.60, 95% CI 1.01–2.53) remained independently associated with mortality, while glucose was no longer statistically significant. CRP, albumin, and CAR were not significantly associated with in-hospital mortality. Subgroup analyses showed consistent results across age and sex strata. Conclusion: In critically ill COPD patients, glucose and creatinine levels upon ICU admission were independently associated with in-hospital mortality, whereas inflammation- and nutrition-related markers, such as CRP, albumin, and CAR, were not. However, given that albumin is heavily influenced by systemic inflammation, it cannot serve as a standalone nutritional marker in the ICU setting. Composite nutritional scores such as the Nutritional Risk Screening (NRS-2002) or the Global Leadership Initiative on Malnutrition (GLIM), which were not available in the MIMIC-IV database, may provide more accurate assessments. These findings highlight the need for integrated risk models incorporating metabolic and renal parameters for early prognostication. Full article

With the large-scale integration of renewable energy devices into the power grid, the voltage stability of the renewable energy base is becoming increasingly weak, and the problem of transient overvoltage is becoming increasingly severe. Grid-forming (GFM) converters can provide strong voltage support. When GFM converters are paralleled with grid-following (GFL) converters, they can effectively reduce transient overvoltage. However, hybrid systems involve many parameters and exhibit complex dynamics, making assessment of transient overvoltage difficult. To address this, this paper first uses Thevenin’s theorem to reduce the renewable transmission system to an equivalent model. Next, the voltage assessment of the hybrid system is analyzed across the pre-fault, mid-fault, and post-fault stages of a short-circuit fault. Then, based on the characteristics of a phase-locked loop (PLL), this paper innovatively derives an assessment method for transient overvoltage at the common coupling point (PCC) under different PLL stability conditions. Additionally, the influence of GFL converter parameters, GFM converter parameters, the GFM capacity ratio on transient overvoltage, and the external system reactance are analyzed. Finally, the proposed evaluation method and factor analysis are validated through electromechanical transient simulation using the simulation software STEPS v2.2.0. Full article

Micro and small wind turbines (MAWTs) are increasingly integrated into residential and prosumer hybrid energy systems. However, their real-world performance often falls short of catalog specifications due to mismatched wind resources, siting limitations, and insufficient attention to human comfort. This paper presents a comprehensive decision-support framework for selecting the type and scale of MAWTs under actual local conditions. The energy assessment module combines aerodynamic performance scaling, wind speed-frequency modeling based on Weibull distributions, turbulence intensity adjustments, and component-level efficiency factors for both horizontal and vertical axis turbines. The framework addresses three key design objectives: efficiency—aligning turbine geometry and control strategies with local wind regimes to maximize energy yield; comfort—evaluating candidate designs for noise emissions, shadow flicker, and visual impact near buildings; and climate adaptation—linking turbine siting, hub height, and rotor type to terrain roughness, turbulence, and built environment characteristics. Case studies from low and moderate wind locations in Central Europe demonstrate how multi-criteria filtering avoids oversizing, improves the autonomy of hybrid PV–wind systems, and identifies configurations that may exceed permissible limits for noise or flicker. The proposed methodology enables evidence-based deployment of MAWTs in decentralized energy systems that balance technical performance, resilience, and occupant well-being. Full article

In mountainous canyon regions, BeiDou Navigation Satellite System (BDS)/Global Navigation Satellite System (GNSS) receivers are susceptible to multireflection and tropospheric factors, which frequently reduce the accuracy in monitoring vertical deformation monitoring under short-baseline methods. This limitation hinders the application of BDS/GNSS in high-precision monitoring scenarios in those cases. To address this issue, this study proposes a three-dimensional (3D) deformation measurement method that integrates BDS/GNSS positioning with dihedral corner reflectors (CRs). By incorporating high-precision horizontal positioning results obtained from BDS/GNSS into the radar line-of-sight (LOS) correction process and utilizing ascending and descending Synthetic Aperture Radar (SAR) data for joint monitoring, the method achieves millimeter-level- accuracy in measuring vertical deformation at corner reflector sites. At the same time, it enhances the 3D positioning accuracy of BDS/GNSS to the 1 mm level under short-baseline configurations. Based on monitoring stations deployed at the Jinsha River dam site, the proposed deformation fusion monitoring method was validated using high-resolution SAR imagery from Germany's TerraSAR-X (TSX) satellite. Simulated horizontal and vertical displacements were introduced at the stations. The results demonstrate that BDS/GNSS achieves better than 1 mm horizontal monitoring accuracy and a vertical accuracy of around 5 mm. Interferometric SAR (InSAR) CRs achieve approximately 2 mm in horizontal accuracy and 1 mm in vertical accuracy. The integrated method yields a 3D deformation monitoring accuracy better than 1 mm. This paper’s results show high potential for achieving high-precision deformation observations by fusing BDS/GNSS and dihedral CRs, offering promising prospects for deformation monitoring in reservoir canyon regions. Full article

Cutaneous leishmaniasis (CL) is a vector-borne parasitic disease caused by protozoa of the Leishmania genus. Once confined to endemic regions such as the Middle East, Americas, North Africa, and Central Asia, CL is increasingly emerging in non-endemic areas due to a multitude of drivers, including population displacement, environmental disruption, and political instability. These overlapping drivers contribute to expanding sand fly habitats, degrading living conditions, and weakening health systems, increasing transmission. Rising global temperatures further facilitate vector expansion into new regions, where clinical unfamiliarity often leads to misdiagnosis, delayed treatment, increased morbidity, and greater financial burden. Despite its rising incidence and global spread, CL remains a neglected tropical disease since it is seldom fatal, with scant interest by public health authorities and financial donors, limiting activities that further research and prevent spread of the disease. This review synthesizes current evidence on how geopolitical instability, forced migration, and climate-driven ecological changes collectively reshape CL epidemiology and complicate diagnosis, treatment, and surveillance. As CL extends beyond traditional geographic boundaries, it requires integrated strategies that address its multifaceted drivers through strengthened cross-border surveillance, provider education, and international coordination—focusing on prevention, diagnosis, and equitable access to diagnostics and therapeutics, especially among displaced and underserved populations. Full article

Core mathematics courses are fundamental to the academic success of engineering students in higher education. These courses equip students with skills and knowledge applicable to their specialized fields. However, first-year engineering students often face significant challenges in mathematics due to a range of factors, including insufficient preparation, mathematics anxiety, and difficulty connecting theoretical concepts to real-life applications. The transition from secondary to tertiary mathematics remains a key area of educational research, with ongoing discussions about effective pedagogical approaches for teaching engineering mathematics. This study utilized a belief survey to gain general insights into the attitudes of first-year mathematics students towards the subject. In addition, it employed the activity theory framework to conduct a deeper exploration of the experiences of first-year engineering students, aiming to identify contradictions, or “tensions,” encountered within a flipped-classroom learning environment. Quantitative data were collected using surveys that assessed students’ self-reported confidence, competence, and knowledge development. Results from Friedman’s and Wilcoxon’s Signed-Rank Tests, conducted with a sample of 20 participants in 10 flipped-classroom sessions, statistically showed significant improvements in all three areas. All of Friedman’s test statistics were above 50, with p-values below 0.05, indicating meaningful progress. Similarly, Wilcoxon’s Signed-Rank Test results supported these findings, with p values under 0.05, leading to the rejection of the null hypothesis. The qualitative data, derived from student questionnaire comments and one-to-one interviews, elucidated critical aspects of flipped-classroom delivery. The analysis revealed emerging contradictions (“tensions”) that trigger “expansive learning”. These tensions encompassed the following: student expectation–curriculum structure; traditional versus novel delivery systems; self-regulation and accountability; group learning pace versus interactive learning; and the interplay between motivation and anxiety. These tensions are vital for academic staff and stakeholders to consider when designing and delivering a first-year mathematics course. Understanding these dynamics can lead to more effective, responsive teaching practices and support student success during this crucial transition phase. Full article

Streak cameras, essential for ultrahigh temporal resolution diagnostics in laser-driven inertial confinement fusion, underpin the streak tube imaging LiDAR (STIL) system—a flash LiDAR technology offering high spatiotemporal resolution, precise ranging, enhanced sensitivity, and wide field of view. This study establishes a theoretical model of the STIL system, with numerical simulations predicting limits of temporal and spatial resolutions of ~6 ps and 22.8 lp/mm, respectively. Dynamic simulations of laser backscatter signals from targets at varying depths demonstrate an optimal distance reconstruction accuracy of 98%. An experimental STIL platform was developed, with the key parameters calibrated as follows: scanning speed (16.78 ps/pixel), temporal resolution (14.47 ps), and central cathode spatial resolution (20 lp/mm). The system achieved target imaging through streak camera detection of azimuth-resolved intensity profiles, generating raw streak images. Feature extraction and neural network-based three-dimensional (3D) reconstruction algorithms enabled target reconstruction from the time-of-flight data of short laser pulses, achieving a minimum distance reconstruction error of 3.57%. Experimental results validate the capability of the system to detect fast, low-intensity optical signals while acquiring target range information, ultimately achieving high-frame-rate, high-resolution 3D imaging. These advancements position STIL technology as a promising solution for applications that require micron-scale depth discrimination under dynamic conditions. Full article

Wheat is a crucial crop for human nutrition, and the demand for high-quality indicators within the “from farm to fork” concept is increasing. Based on this premise, this study examined how, at the farm level, the fertilization system can influence key quality indicators relevant to wheat production and final products. This research was conducted under specific conditions of the Western Plain of Romania at the Agricultural Research and Development Station (ARDS), Lovrin, during 2015–2017. Fertilization involved the autumn application of phosphorus (concentrated superphosphate; 0, 40, 80, 120, 160 kg ha⁻¹ active substance, a.s.) and potassium (potassium chloride; 0, 40, 80, 120 kg ha⁻¹ a.s.). Nitrogen (ammonium nitrate; 0, 30, 60, 90, 120 kg ha⁻¹ active substance) was applied in spring in two stages. The combination of these three fertilizers resulted in 18 fertilized variants (T2 to T19), tested alongside an unfertilized control (T1). The experimental variants were arranged in four randomized replications. Grain quality was assessed based on protein content (PRO, %), gluten (GLT, g 100 g⁻¹), gliadins (Gliad, %), glutenins (Glut, g 100 g⁻¹), high-molecular-weight glutenins (HMW, g 100 g⁻¹), low-molecular-weight glutenins (LMW, g 100 g⁻¹), and the gliadin/glutenin ratio (Gliad/Glut). Compared to the average values for each indicator across the experiment, certain variants produced values above the mean, with statistical significance. Variant T16 stood out by producing values above the mean for all indicators, with statistical confidence. Multivariate analysis showed that five indicators with very strong (PRO, GLT) and strong (HMW, Glut, LMW) influence grouped in PC1, while two indicators (Gliad, Gliad/Glut) with very strong and strong influence grouped in PC2. The analysis revealed varying levels of correlation between the applied fertilizers, with nitrogen (N) showing very strong and strong correlations with most indicators, while phosphorus and potassium showed moderate-to-weak correlations. Regression analysis generated mathematical models that statistically described how each indicator varied in relation to the fertilizers applied. Full article

Background/Objectives: Reflecting the interaction between dissolution and absorption, the biphasic dissolution system is an appealing approach for estimating the intestinal absorption of drugs in humans. The study aims to characterize the suitability of the biphasic in vitro dissolution testing to set up an in vitro–in vivo correlation (IVIVC) for the original and generic immediate-release (IR) tablets of a Biopharmaceutics Classification System (BCS) Class II drug, bicalutamide (BIC). Methods: USP apparatus II paddle was used to conduct dissolution testing. A level A IVIVC was obtained between in vitro partitioning and in vivo absorption data of the original drug. The single-compartmental modeling was used for pharmacokinetic (PK) analysis. The generic product’s plasma concentrations were estimated. Results: There was a good correlation between in vitro and in vivo data (r² = 0.98). The area under the concentration–time curve (AUC) and maximum plasma concentration (C_max) ratios for generic/original were 1.04 ± 0.01 and 0.951 ± 0.026 (mean ± SD), respectively. Conclusions: The biphasic dissolution testing may present an in vivo predictive tool for developing generic products of poorly soluble and highly permeable drugs such as BIC, which are characterized by pH-independent poor solubility. Full article