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Construction of a New Hypersurface Family Using the Spherical Product in Minkowski Geometry
No full textThe spherical product of two curves, composed of a total of n components, gives rise to spherical product surfaces in Euclidean space (Formula presented.), frequently resulting in surfaces of revolution, including superquadrics, which often exhibit inherent symmetry. When (Formula presented.) -planar curves are considered, this construction enables the generation of hypersurfaces in n-dimensional spaces. Building upon this geometric framework, we conduct the first-ever investigation of spherical product hypersurfaces in the context of Minkowski geometry. We define these hypersurfaces in four-dimensional Minkowski space (Formula presented.) and derive explicit expressions for their Gaussian and mean curvatures. We also determine the conditions under which such hypersurfaces are flat or minimal. Furthermore, we reinterpret certain hyperquadrics as specific instances of spherical product hypersurfaces in (Formula presented.), supported by visual illustrations. Finally, we extend the construction to arbitrary-dimensional Minkowski spaces, providing a unified formulation for spherical product hypersurfaces across higher-dimensional Lorentzian geometries
Bridging performance and sustainability in supercapacitors: A review of advanced materials and synthesis strategies
No full textSupercapacitors (electrochemical double-layer capacitors (EDLCs), hybrids, and pseudocapacitive types) bridge the gap between conventional capacitors and batteries. They offer high power densities (kW kg−1 range), rapid charging, and cycle lives exceeding 106 cycles. The global market is growing rapidly; valued at ~3.0 billion USD in 2024, it is projected to reach ~14.7 billion USD by 2034 with a Compound Annual Growth Rate (CAGR) of ≈17.5%. To meet the demands of this expanding market, increasing energy density is a priority. While current EDLCs typically provide 5–10 Wh kg−1, hybrid systems exceed 20 Wh kg−1, and prototypes are now approaching 60 Wh kg−1, which significantly enhances electric vehicle (EV) applications. This review summarizes advances from 2020 to 2025 in electrode materials, including carbons, transition metal compounds, two-dimensional transition metal carbides and nitrides (MXenes), Metal-Organic Frameworks (MOFs), Covalent Organic Frameworks (COFs), and conducting polymers. It also analyzes electrolytes (aqueous, water-in-salt, organic, ionic liquid, and solid/quasi-solid) and device concepts such as asymmetric and micro-supercapacitors. The discussion emphasizes material–electrolyte synergies, sustainable electrode design, and scalable synthesis. Unlike previous reviews, this work critically evaluates materials based on industrial feasibility, cost, and environmental footprint, rather than just capacitance. Despite rapid progress, challenges remain in enhancing energy density and ensuring sustainable manufacturing. Future research must focus on safe electrolytes and hybrid integration to establish supercapacitors as reliable energy storage technologies
An experimental investigation on the influence of auxiliary heater position and wavy fin inclination on the performance of a novel hybrid solar air heater with phase change material
No full textMaintaining a stable and adequate outlet air temperature under fluctuating weather conditions remains a critical challenge in solar air heater applications. This study presents an experimental investigation of a novel hybrid double-pass solar air heater equipped with wavy fins featuring air gaps and a latent heat thermal storage unit, with a particular focus on improving outlet temperature stability. Indoor experiments considering various fin inclination angles (30°, 45°, and 60°) were initially conducted to determine the optimal fin inclination angle in order to enhance thermal performance, revealing 45° as the most effective. Following this phase, outdoor experiments evaluated the influence of the electric auxiliary heater's position on thermal behavior and energy consumption, where the auxiliary heater was installed either at the U-turn section (configuration 1) or at the outlet section (configuration 2). The findings indicate that configuration 2 achieved a more stable outlet temperature of 54 ± 1.3 °C. This configuration provided a maximum temperature rise of 32 °C, from an ambient temperature of 24 °C, and exhibited lower top heat losses. Further, configuration 2 reduced the electrical energy consumption by 4.2 % compared to configuration 1. Furthermore, the system demonstrated average thermal efficiencies of 65.6 % and 68.1 % for configurations 1 and 2, respectively, with a favorable energy payback time of 0.49 years, making it a simple and sustainable solution for various agricultural and industrial applications
Sustainable nanosystems for targeted drug delivery and their impacts on combination therapies and personalized medicine: Advancements and perspectives
No full textRecent advances in sustainable nanosystems for targeted drug delivery have emphasized biodegradable and biocompatible nanocarriers synthesized through eco-friendly methods to enable precise, controlled, and stimuli-responsive drug release with minimal environmental impact. This review focuses on green-synthesized and sustainable nanocarriers, highlighting emerging strategies that prioritize environmentally responsible design. Eco-friendly fabrication techniques, including microfluidics, solvent-free processes, supercritical fluid methods, and ionic gelation, are discussed for their potential to reduce resource use and environmental burden. Moreover, biomimetic approaches such as cell membrane-coated nanoparticles, virus-like particles, peptide-based nanostructures, and DNA/RNA carriers are examined for their enhanced targeting efficiency and biological compatibility. Besides, the use of waste-derived materials as renewable resources is also explored, reflecting the growing influence of circular economy principles in pharmaceutical nanotechnology. Furthermore, key applications in cancer, infectious diseases, and neurological disorders are summarized, with emphasis on stimuli-responsive platforms that support precision therapy. The novelty of this review lies in its integrated perspective that unifies green synthesis, circular-economy materials, and biomimetic engineering to present a comprehensive roadmap for next-generation sustainable drug delivery. We have also discussed challenges such as material variability, reproducibility, safety concerns, and scale-up issues, while also providing insights into future directions focused on renewable materials, sustainable manufacturing strategies, and smart multifunctional nanosystems
Kocaeli ilinde görev yapmakta olan hekimlerde depresyon ve anksiyete bozukluklarının görülme sıklığının ve buna etki eden faktörlerin belirlenmesi
No full textLaser Surface Texturing of AA1050 Aluminum to Enhance the Tribological Properties of PTFE Coatings with a Taguchi-Based Analysis
No full textFiber laser surface texturing was applied to AA1050 aluminum to improve friction and wear performance of PTFE coatings. A Taguchi L16 design varied texture geometry (square, diamond, hexagon, circle), scanned area ratio (20% to 80%), and laser power (40 to 100 W) prior to primer plus PTFE topcoat deposition (25 to 35 µm). Dry reciprocating sliding against a 6 mm 100Cr6 ball was conducted at 20 N, 1 Hz, and 50 m, and wear track geometry was measured by non-contact profilometry. The non-textured reference exhibited an average COF of 0.143, whereas the lowest mean COF was achieved with diamond 60% and 40 W (0.095) and the highest with hexagon 60% and 100 W (0.156); hexagon 20% and 60 W matched the reference. ANOVA indicated scanned area ratio as the dominant contributor to COF (39.72%), followed by geometry (35.07%) and power (25.21%). Profilometry confirmed reduced coating penetration for optimized textures: the reference wear track was approximately 1240 µm wide and 82 µm deep, compared with 930 µm and 34 µm for square 80% and 40 W, 997 µm and 39 µm for diamond 60% and 40 W, and 965 µm and 36 µm for hexagon 40% and 40 W.</p
Halogen-induced electronic modulation and nonlinear optical enhancement in a 6-iodopyridine-2-carboxylate Ni(II) complex: An experimental and DFT study
No full textA nickel(II) coordination complex, [Ni(6Ipca)2(4,4dmdpy)], was synthesized using 6-iodo-pyridine-2-carboxylic acid (6IpcaH) and 4,4′-dimethyl-2,2′-dipyridyl (4,4dmdpy). The crystal structure, determined via single-crystal X-ray diffraction, reveals a distorted octahedral geometry around the Ni(II) center. The thermal stability of Ni(II) complex was studied by employing TG-DTA analysis. The structural framework was corroborated by DFT (B3LYP/LanL2DZ) calculations, which also supported vibrational modes observed in FT-IR spectra. Frontier molecular orbital (FMO) and natural bond orbital (NBO) analyses demonstrated enhanced electron delocalization and significant ligand-to-metal charge transfer. Static and frequency-dependent first- and second-order hyperpolarizability parameters (β and γ) revealed substantial nonlinear optical (NLO) responses, with the complex exhibiting higher γ(-ω;ω,0,0) (228.45 × 10–36 esu) values compared to its free ligands. Furthermore, molecular docking simulations against CDK8 kinase showed improved binding affinity (-6.29 kcal/mol, Ki = 24.35 µM) for the Ni(II) complex relative to its uncoordinated ligands, suggesting potential antitumor relevance. These findings position the synthesized Ni(II) complex as a promising multifunctional candidate for NLO applications and biomedical research
A comprehensive survey on pose estimation and tracking in sports: methodologies, datasets, challenges, and future directions
No full textPose estimation and tracking in sports has gained significant attention due to its potential to revolutionize performance analysis, injury prevention, and strategic decision-making. This survey presents a comprehensive overview of the methodologies, datasets, challenges, and future directions in this rapidly evolving field. We explore traditional approaches, including geometric and statistical models, and highlight the transformative impact of deep learning techniques, such as convolutional neural networks, transformers, and hybrid architectures, which have enabled highly accurate and robust pose estimation. The paper also discusses dataset creation and ground-truthing techniques tailored to sports contexts, emphasizing the importance of multimodal data, scalability, and representativeness. Applications across diverse sports, from individual to team-based activities, demonstrate the versatility of pose estimation systems in both real-time and offline settings. However, challenges such as occlusions, dynamic backgrounds, and computational efficiency persist, necessitating further innovation. We identify future research directions, including the integration of multimodal data, edge computing, and ethical considerations, to enhance accuracy, interpretability, and generalizability. This survey aims to provide a foundational reference for researchers and practitioners, fostering advancements in pose estimation and tracking technologies that meet the unique demands of sports analytics
