Search Results (9,353)

The proliferation of power converters in modern energy production systems has led to increased harmonic content due to the commutation of active switching devices. This increase in harmonics contributes to lower system efficiency, reduced power factor, and consequently, a higher reactive power requirement. To address these issues, this paper presents both simulation and experimental results of various control strategies implemented on Parallel Voltage Source Inverters (PVSI) for harmonic mitigation. The proposed control strategies are categorized into direct and indirect control methods. The direct control techniques implemented include the instantaneous power method (PQ), the synchronous algorithm (DQ), the maximum principle method (MAX), the algorithm based on synchronization of current with the voltage positive-sequence component (SEC-POZ), and two methods employing the separating polluting components approach using a band-stop filter and a low-pass filter. The main innovation in these active power filter (APF) control strategies, compared to traditional or existing technologies, is the real-time digital implementation on high-speed platforms, specifically FPGAs. Unlike slower microcontroller-based systems with limited processing capabilities, FPGA-based implementations allow parallel processing and high-speed computation, enabling the execution of complex control algorithms with minimal latency. Additionally, the enhanced reference current generation achieved through the seven applied methods provides precise harmonic compensation under highly distorted and nonlinear load conditions. Another key advancement is the integration with Smart Grid functionalities, allowing IoT connectivity and remote diagnostics, which enhances system monitoring and operational flexibility. Following validation on an experimental test bench, these algorithms were implemented and tested on industrial APF prototypes powered by a standardized three-phase network supply. All control strategies demonstrated an effective reduction in total harmonic distortion (THD) and improvement in power factor. Experimental findings were used to provide recommendations for choosing the most effective control solution, focusing on minimizing THD and enhancing system performance. Full article

Minerals are essential for ruminant health, productivity, and metabolic function, with trace minerals playing critical roles at narrow dietary margins. Cobalt (Co) is essential as it supports ruminal microbial synthesis of vitamin B12 (cobalamin), which acts as a crucial cofactor in energy and protein metabolism. This review summarizes the role of cobalt in dairy cattle nutrition, emphasizing its contribution to vitamin B12 synthesis, propionate metabolism, and milk production. Only 3–15% of dietary cobalt is converted to vitamin B12, and efficiency depends on dietary composition, forage-to-concentrate ratio, and ruminal microbiome. Deficiency leads to reduced intake, poor growth, anemia, reproductive failure, and decreased milk yield. Cow’s milk contains ~0.5 µg/L of vitamin B12, with greater concentrations in colostrum; diet composition, supplementation, and genetics contribute to variability. Current recommendations set the cobalt requirement at 0.2 mg/kg diet DM, yet multiple environmental and nutritional factors can restrict vitamin B12 synthesis. Limitations of this review include heterogeneity among the studies reviewed, such as differences in trial design, animal genetics, diet composition, and environmental conditions, which may introduce variability and affect the generalizability and consistency of the findings. Collectively, findings highlight cobalt’s pivotal role in supporting microbial activity, energy metabolism, and production outcomes in dairy cows. Full article

This paper presents the effect of modifiers on the properties of a mixture of asphalt concrete with bitumen emulsion (ACBE). The mineral-asphalt mixture is the only one that can be produced using the cold-mix technology (CMA). The theoretical part of the article details the characteristics of the methods for producing mineral-asphalt mixtures in terms of their production temperature. Thus, hot (HMA), half-warm (H-WMA), warm (WMA) and cold (CMA) mixtures are discussed. The research section presents the design of the asphalt concrete composition with bitumen emulsion, the research methods, the experiment design and the research results. The design of the mixture of asphalt concrete with bitumen emulsion was carried out in accordance with the guidelines set out in EN 13108-31. In the experiment, Portland cement (C), bitumen emulsion (A), synthetic latex (styrene-butadiene rubber SBR) (B) and redispersible polymer powder EVA (polyethylene-co-vinyl acetate) (P) were used as modifiers. Twenty-four mixtures were designed as part of the experiment, according to the 3⁴ experiment design. The following physical and mechanical properties were assessed in the design of the research: air void content V_m, water ab-sorption n_w, indirect tensile strength ITS and IT-CY stiffness modulus. When analysing the research results, the authors observed a noticeable impact of the content of asphalt (A) and synthetic latex (B) on the air void content V_m. A significant effect was also observed for the interaction of Portland cement (C) and redispersible polymer powder (P) on the indirect tensile strength ITS. The next step was the optimisation of the ACBE mixture composition, which effect made it possible to identify the optimum amounts of modifiers in the mixture of asphalt concrete with bitumen emulsion (ACBE), which constituted recommendations for the requirements for mixtures of asphalt concrete with bitumen emulsion. Full article

Background: Chronic venous disease (CVD) substantially influences workers’ comfort, productivity, and capacity to remain employed, yet many occupational settings complicate the implementation of effective symptom management strategies. Temperature fluctuations, in particular, influence daily functioning: heat often worsens swelling, heaviness, pain, and fatigue, while cold may offer partial relief. This study examines how workplace thermal and organizational conditions affect adults with CVD, paying attention to the challenges they face in applying clinical recommendations. Methods: Fifty adults with CEAP C1–C6 disease were interviewed and observed in clinical settings. A qualitative descriptive approach was adopted to capture workers’ accounts rather than generate a new theory. Data were analyzed using Braun and Clarke’s reflexive thematic analysis within a qualitative descriptive framework. Results: Heat exposure consistently aggravated swelling, pain, and fatigue, whereas moderate cold often improved comfort and functional capacity. Participants highlighted numerous workplace barriers, including rigid schedules, restrictive uniforms, and difficulties maintaining compression in hot environments. Supportive supervisors, micro-breaks, access to hydration, and flexibility in posture facilitated better symptom control. Workers frequently described tensions between clinical advice and job demands, noting that instructions such as leg elevation or frequent breaks were often unrealistic in their occupational context. Conclusions: Aligning clinical guidance with workplace realities is essential for the well-being and long-term employability of individuals with CVD. Climate-sensitive and ergonomic job design represents an important strategy for supporting employees’ ability to manage symptoms and sustain productivity amid increasing thermal variability. Full article

Potatoes, possessing the characteristics of being suitable for food crop, vegetable, and fodder use, have become an important supplementary product for ensuring food security and vegetable supply. Their price fluctuations play a significant role in regulating production and consumption. Against the backdrop of establishing a unified national market, studying potato price fluctuations from a spatial perspective is crucial for scientifically and systematically understanding the patterns of China’s potato market. This study employs Ensemble Empirical Mode Decomposition, Spatial autocorrelation and Vector Autoregression models to analyse spatial variations and inter-regional transmission mechanisms in China’s potato price fluctuations, utilising wholesale market price data from January 2014 to December 2024 across diverse regions. Findings indicate distinct spatial patterns in potato price dynamics with significant inter-regional interactions. The Northern Crop Region exhibits predominantly short-term, high-frequency fluctuations, whereas the Central Crop Region, Southern Crop Region, and Southwestern Crop Region are characterized by long-term, low-frequency fluctuations. Potato prices in China exhibit significant spatial heterogeneity, and potato price fluctuations at both national and regional levels are primarily influenced negatively by those in other regions. The degree of interactive influence between potato prices across regions exhibits considerable variation, with the Central China crop region holding a certain degree of dominance in the national market. Based on these findings, policy recommendations are proposed, including strengthening tiered and regional monitoring and analysis of potato prices, standardizing inter-regional transmission pathways for potato prices, and guiding the formation of a complementary regional structure for potato production. Full article

Based on the “three-dimensional” perspective of modern circulation theory, this study constructs an index system for evaluating the circulation efficiency of agricultural products. The circulation efficiency index values are computed from panel data from 2015 to 2022 in China, and regression estimation is applied to estimate their impact on contract farming coverage. The findings reveal that the circulation efficiency of agricultural products has a significant driving effect on the development of contract farming, and the key mechanism lies in logistics efficiency. Moreover, its impact exhibits regional heterogeneity. Accordingly, we propose policy recommendations to improve contract farming coverage. Full article

This study explores the intricate relationship between trade openness, energy intensity, technological innovation, and carbon emissions across emerging and advanced economies, emphasizing their implications for sustainable development. Using balanced panel data, the analysis employs the Method of Moments Quantile Regression (MMQR) and Dumitrescu–Hurlin panel causality approaches to capture heterogeneous effects across varying emission levels. The results reveal that trade openness plays a pivotal role in mitigating carbon emissions by facilitating access to cleaner technologies and promoting energy-efficient production processes. Conversely, energy intensity demonstrates a positive and significant association with carbon emissions, confirming the persistence of fossil fuel dependence in energy structures. Technological innovation exhibits asymmetric effects—reducing emissions in emerging economies while marginally increasing them in advanced economies due to rebound effects associated with industrial expansion. The causality analysis highlights bidirectional linkages among trade openness, energy intensity, and emissions, suggesting that economic and environmental dynamics are mutually reinforcing. These findings imply that both emerging and advanced economies must design integrated policies that align trade liberalization with energy transition strategies and innovation-driven decarbonization. The study contributes novel insights into the energy–carbon nexus by distinguishing the heterogeneous impacts of trade and innovation across different development stages, thereby offering actionable recommendations for achieving global low-carbon growth. Full article

Incorporating biochar into pavement materials is a novel and environmentally sustainable approach that aligns with global sustainability goals and advances greener pavement technologies. Studies have shown that biochar significantly enhances the strength, durability, and stability of pavements, while also contributing to sustainability by lowering the carbon footprint associated with traditional construction materials. Additionally, the incorporation of biochar contributes to the sustainability of asphalt engineering by reducing reliance on petroleum-based products and promoting the valorization of biomass. The primary objective of this review is to critically evaluate and synthesize existing research on the use of biochar in bitumen and asphalt mixtures, identifying key performance trends, influencing factors, and optimum modification conditions. Despite these benefits, several drawbacks and challenges remain. These include variability in biochar properties, determining the optimal dosage for different applications, and the lack of standardized testing methods. This review investigates a wide range of studies and experimental investigations that evaluate the sources and production methods of biochar, as well as its effects on bitumen binders and asphalt mixtures. Furthermore, the paper highlights the environmental consideration of biochar modification, including carbon sequestration and Life cycle assessment. Substantial findings and their engineering implications are presented, along with recommendations for future research aimed at advancing the broader adoption of biochar in sustainable pavement engineering, in alignment with the principles of the circular economy. Full article

Blackberry (Rubus subg. Eubatus Focke) ranks among the four most commercially valuable berry crops globally, alongside raspberry, strawberry, and blueberry, owing to its high antioxidant content—particularly flavonoids, anthocyanins, and polyphenols. Compared to other berry crops, blackberry cultivation requires lower labor and financial inputs, with plantations remaining productive for 12–15 years. In Russia, total blackberry area is limited (~100 ha), and the Moscow Region is particularly suited for trailing and semi-trailing cultivars with early-to-mid-season ripening. This three-year study (2021–2023) conducted at the Tsitsin Main Botanical Garden (RAS) evaluated ten promising blackberry cultivars to (i) assess interrelationships among phenological, morphological, and fruit quality traits; and (ii) identify optimal market niches for each genotype. Cultivars were grouped by ripening time: early (‘Karaka Black’, ‘Loch Tay’, ‘Natchez’) and medium (‘Columbia Sunrise’, ‘Hall’s Beauty’, ‘Caddo’, ‘Columbia Giant’, ‘Victoria’, ‘Brzezina’). Morphologically, ‘Columbia Giant’, ‘Columbia Star’, ‘Columbia Sunrise’, ‘Hall’s Beauty’, and ‘Loch Tay’ exhibited the most balanced architecture. For fresh-market retail, ‘Hall’s Beauty’ (650.3 gf), ‘Loch Tay’ (632.0 gf), and ‘Victoria’ (882.2 gf) stood out for high fruit firmness, whereas ‘Columbia Giant’ (11.5 g fruit mass, 354.1 gf) is recommended for direct consumer sales due to its large fruit size and acceptable firmness. Key trait associations included flowering duration and drupelet number (r = −0.83); fruiting onset and lateral length (r = 0.75); central leaflet length and fruiting laterals per shoot (r = −0.86); fruit number per lateral and Soluble Solids Content (SSC, r = 0.83); and lateral length (r = 0.84). These findings indicate the importance of proper variety selection for establishing blackberry plantations in the specific climatic conditions of the Moscow Region. Full article

This study examines the feasibility of incorporating cathode-ray tube (CRT) panel glass as a partial replacement of natural aggregate in concrete, aiming to promote sustainable material utilization without compromising structural performance. Nine mixtures were prepared using three cement types—Normal 42.5 N, PC 50M(S-V-L) 42.5 N; Profi 42.5 R, PC 20M(S-L) 42.5 R; and Cement without additions, CEM I 42.5 R—and three CRT contents (0%, 5%, and 10%). A comprehensive experimental program was conducted, including tests on natural aggregates, mortars, and concrete in both fresh and hardened states, as well as flexural testing of reinforced concrete beams, supported by ground-penetrating radar (GPR) and digital image correlation (DIC) measurements. The results revealed that replacing up to 5% of natural aggregate with CRT glass had negligible effects on workability and density while slightly improving compressive and flexural strength. At 10% replacement, a minor reduction in strength and ductility was observed. Durability-related parameters, such as water absorption and carbonation depth, increased slightly but remained within acceptable limits. Flexural tests confirmed that beams with 5% CRT content exhibited comparable load capacity and crack propagation to reference beams. This study represents the first combined application of Digital Image Correlation (DIC) and Ground-Penetrating Radar (GPR) in evaluating reinforced concrete beams with CRT-modified concrete across different cement types. The results showed that incorporating 5% CRT glass increased flexural tensile strength by up to 15% compared with the control mix, confirming both the structural feasibility and sustainability of such composites. Overall, the findings indicate that CRT panel glass can be effectively utilized up to a 5% replacement level, offering both environmental and structural advantages for sustainable concrete production. Based on the experimental results, a replacement level of up to 5% CRT glass is recommended for structural concrete applications under the tested conditions, where CRT particles replaced the 4–8 mm medium aggregate fraction, as it ensures a balance between strength, ductility, and durability. Full article

Biochar has gained attention as a promising soil amendment capable of improving soil structure, nutrient retention and plant resilience to stress. However, its performance in perennial horticultural systems, particularly during the early stages of orchard establishment, remains insufficiently documented. This study, conducted in 2021 in a newly established apple orchard (‘Gala Brookfield Baigent’/P 60) in Wieluń, Central Poland, aimed to evaluate the effectiveness of three methods of using cattle-manure-derived biochar at a dose of 10 t ha⁻¹ (application before ploughing prior to orchard establishment, application to planting holes and surface spreading). Neither tree growth nor fruiting potential were affected by biochar, which made the comparison of its application methods inconclusive. According to the principal component analysis performed, mineral nitrogen showed a tendency to promote the formation of mixed-type buds on short shoots, a propitious growing pattern for intensive orchard management. In contrast, compost fertilisation favoured vegetative growth over generative development, as reflected by the significantly negative coefficient in regression analysis (b = −0.12; 95% CI: −0.25 to –0.00 for the Box-Cox-scaled fruiting-to-growth potential ratio). Nonetheless, the overall growth response of apple trees in the first year after planting to the applied soil-enriching practices was rather modest, with this observation validating the strategy of reducing fertiliser doses during orchard establishment on productive soils maintained in good agricultural condition. Long-term studies under abiotic or nutrient-limiting constraints, as well as the combined use of biochar with microbial inoculants, are recommended to fully elucidate its potential in apple production. Full article

Cannabidiol (CBD) has transitioned from anecdotal use to an evidence-based adjunctive therapy for Lennox–Gastaut syndrome, Dravet syndrome, and tuberous sclerosis complex. This review integrates knowledge on CBD’s pharmacology, pharmacokinetics, and clinical implementation, with focus on metabolism, therapeutic drug monitoring (TDM), and clinically relevant interactions with antiseizure medications. CBD exerts CB1/CB2-independent mechanisms—prominently GPR55 antagonism, TRP-channel desensitization, and adenosine-mediated network dampening—supporting efficacy across heterogeneous seizure phenotypes. Its pharmacokinetic profile is characterized by low and variable oral bioavailability, a pronounced food effect, extensive tissue distribution, and phase I/II biotransformation to the active 7-hydroxy-CBD and abundant 7-carboxy-CBD, resulting in substantial inter-individual variability and liability for drug–drug interactions. Clinically salient interactions include CYP2C19-mediated elevation of N-desmethylclobazam and increased transaminases in valproate co-therapy. We summarize emerging TDM practices—standardized fed-state trough sampling with paired measurement of CBD and 7-hydroxy-CBD—and discuss how preliminary interpretive ranges can support dose optimization, adherence assessment, and safety surveillance. Practical recommendations emphasize interaction-aware titration within evidence-based dose bands, liver function monitoring, and standardized documentation of formulation and sampling conditions. Future work should align pharmacogenomics with TDM, refine bioavailability through advanced delivery systems, and tighten analytical and product-quality standards to consolidate CBD as a precision-ready component of modern epilepsy care. Full article

Background: Breast cancer is the most prevalent cancer among women worldwide, and therapeutic resistance represents a major clinical challenge. Mitochondria are key regulators of cancer metabolism, redox homeostasis, and apoptosis, making them potential therapeutic targets. Aim: This study aimed to evaluate the effects of combined Akt and PARP inhibition on mitochondrial metabolic function, energy production, and apoptosis in breast cancer cells. Methodology: The SRB assay was used to compare the viability of MDA-MB-231 and MCF7 cells. A colony formation assay was conducted to assess the capacity of individual cells to develop colonies, and ROS production was quantified using DHR123. Flow cytometric analysis was performed to evaluate cell death, and the Seahorse Mito stress test was used to measure ATP production and essential mitochondrial parameters. Results: The combination of Akt and PARP inhibitors impaired oxidative phosphorylation without inducing a compensatory shift to glycolysis, leading to reduced ATP production, increased ROS generation, and apoptotic cell death in breast cancer cells compared to monotherapy. Conclusions and Recommendations: These findings indicate that the combination of olaparib and capivasterib is a promising therapeutic strategy for breast cancer. Furthermore, evaluation of in vivo toxicity and antitumor effectiveness is essential to validate its potential. Full article

Background: In pediatric celiac disease (CD), intestinal malabsorption and the restrictive nature of a gluten-free diet (GFD) frequently result in persistent macro- and micronutrient imbalances, despite histological remission. The present review evaluates the evidence on nutritional adequacy of the GFD, identifies common deficiencies, and considers biomarker strategies and dietary recommendations to optimize growth and metabolic health. Methods: A narrative review of the literature was conducted, focusing on studies of nutrient intake, product composition of gluten-free foods, biomarker assessment, and clinical outcomes in children with CD. Both macronutrient (protein, fat, carbohydrate, fiber) and micronutrient (iron, vitamin D, calcium, B-vitamins, zinc, magnesium) domains were included. Results: Children with CD on long-term GFD demonstrate higher intake of lipids (especially saturated fat) and simple carbohydrates, alongside consistently low intake of dietary fiber and key micronutrients. Gluten-free products often exhibit lower protein content, higher glycemic index, and reduced fortification compared to gluten-containing equivalents. Nutritional deficits contribute to impaired linear growth, delayed puberty and increased metabolic risk. Conclusions: Nutritional adequacy of the GFD cannot be assumed in children with CD. Routine monitoring using standardized biomarker panels, combined with personalized dietary counseling and improved formulation and fortification of gluten-free products, is essential to mitigate long-term adverse outcomes. Future work should advance precision nutrition approaches and public-health initiatives to optimize dietary quality in this vulnerable population. Full article

This article focuses on the oil–water emulsification problem during steam injection in heavy oil thermal recovery. Emulsions were prepared through one-dimensional flow experiments, and key parameters including the inversion point water cut and micro-morphological characteristics (particle size and distribution range) of the emulsions were systematically measured under varied conditions (temperature: 150–360 °C; salinity: 0–7500 mg/L; water cut: 10.07–72.22%). By analyzing the experimental data, the emulsification mechanism and influencing rules were revealed: under the combined conditions of high temperature (150–360 °C), high salinity (up to 7500 mg/L), and low water cut (10.07–19.35%), crude oil and formation water form oil-in-water emulsions under the shear action of porous media. During this process, active substances in crude oil react with inorganic salts in formation water to generate natural surfactants, which reduce the oil–water interfacial tension and enhance emulsion stability, enabling the emulsion to maintain stability even at a high water cut of up to 72.22%, with particle sizes ranging from 1 μm to 350 μm and distribution spans varying from 4 μm to 50 μm. The formation of such emulsions leads to a significant increase in viscosity, adversely affecting oil recovery. In production practice, it is recommended to add chemical agents during the early stage of steam huff and puff development (water cut: 10.07–37.50%). This measure aims to destroy the oil–water liquid film, promote water droplet coalescence (narrowing the particle size distribution span), and facilitate emulsion breaking and phase inversion, thereby effectively mitigating the adverse impacts of oil–water emulsions and improving heavy oil recovery efficiency. Full article