Shape Modification Research Articles

Enhancing wind turbine energy efficiency: Tribo-dynamics modeling and shape modification

The performance of wind turbine gearbox planetary bearing systems directly influences the turbine's reliability, energy production efficiency, and economy. However, the lack of a comprehensive model to accurately predict the dynamic meshing load of helical gears and temperature effects hinders a deeper understanding of the transient performance of gearbox planetary sliding bearings. Additionally, research on shape modification for gearbox planetary sliding bearings remains inadequate. This study develops a comprehensive tribo-dynamics model that considers the dynamic meshing forces of helical gears and temperature effects. The model's effectiveness is validated by the concordance between experimental data from a full-size test bench and simulation results on oil film thickness and temperature. Transient simulation analysis indicates insufficient lubrication, high-temperature rise, and severe contact that reduce electricity production efficiency and reliability, all of which occur at bearing axial edges. Therefore, three modified bearing designs (super-elliptical, trapezoidal, and quadratic shapes) are introduced, and their improved performance is thoroughly compared. The super-elliptical design increases the minimum oil film thickness by 2.60 μm. The trapezoidal design reduces cumulative friction energy losses by 4.34 %. Each modified design successfully reduces the edge wear and oil temperature. The underlying enhancing mechanisms are revealed to be oil film uniform redistribution and lubrication states' alteration. This work can contribute to the reliability, electricity production efficiency, and economy of global wind turbines and support the achievement of net-zero emission goals.

Morphological and genetic characterization of mutants of Gladiolus cultivar prince of orange for two successive vegetative generations

Gladiolus mutants developed using gamma irradiations and EMS treatments were characterized using morphological, genetic and Polymerase Chain Reactions (PCR) based Inter-Simple Sequence Repeats (ISSR) for designing future breeding strategies. As many as 7 mutants based on phenotypic variations such as colour and shape modifications were subjected to molecular characterization using 11 ISSR primers that confirmed variations. ISSR markers showed 13.88 to 36.00 percent polymorphism among the mutants was recorded, signifying variability among different mutants. UPGMA (unweighted pair group method with arithmetic mean) based analysis of cluster separated gladiolus variety prince of orange mutants into four clusters. ISSR markers were subjected for comparative analysis like effective multiplex ratio, marker index, polymorphic information content and resolving power wherein, highest EMR (3.24), MI (1.32) were found for UBC 810, Rp (4.37) values were found for UBC 827, and maximum PIC value (0.46) for ISSR 22218 UBC 812. The results clearly indicated the reproducibility of ISSRs and their ability to detect variability among the mutants. A significant level of genetic variation was depicted by ANOVA which suggested the usefulness of studies in gladiolus breeding and unique bands obtained could be utilized for mutant/ varietal identification.

Integrating Compositional and Structural Diversity in Heterometallic Titanium Frameworks by Metal Exchange Methods.

The increasing use of Metal-Organic Frameworks (MOFs) in separation, catalysis, or storage is linked to the targeted modification of their composition or porosity metrics. While modification of pore shape and size necessarily implies the assembly of alternative nets, compositional changes often rely on postsynthetic modification adapted to the functionalization or exchange of the organic linker or the modification of the inorganic cluster by metal exchange methods. We describe an alternative methodology that enables the integration of both types of modification, structural and compositional, in titanium MOFs by metal exchange reaction of the heterometallic cluster Ti2Ca2. A systematic analysis of this reactivity with MUV-10 is used to understand which experimental variables are crucial to enable replacement of calcium only or to integrate metal exchange with structural transformation. The isoreticular expanded framework, MUV-30, is next used to template the formation of MUV-301, a titanium framework not accessible by direct synthesis that displays the largest mesoporous cages reported to date. Given that the interest of Ti MOFs in photoredox applications often meets the limitations imposed by the challenges of titanium solution chemistry to design concrete candidates, this soft strategy based on preassembled frameworks will help integrate specific combinations of metals into high porosity architectures.

Constrained Polynomial Likelihood

We develop a nonnegative polynomial minimum-norm likelihood ratio (PLR) of two distributions of which only moments are known. The sample PLR converges to the unknown population PLR under mild conditions. The methodology allows for additional shape restrictions, as we illustrate with two empirical applications. The first develops a PLR for the unknown transition density of a jump-diffusion process, while the second extracts a positive density directly from option prices. In both cases, we show the importance of implementing the non-negativity restriction.

Effect of Probiotics on Sperm Quality in the Adult Mouse.

The administration of probiotics for the treatment of different diseases has gained interest in recent years. However, few studies have evaluated their effects on reproductive traits. The objective of this study was to examine the effect of two mixtures of probiotics, a commercial probiotic (Vivomixx®) and a mix of Lacticaseibacillus rhamnosus GG and Faecalibacterium duncaniae A2-165, on sperm quality in a mouse model. Adult male mice (8months old) were used for two experimental and one control groups (n = 5 each). The probiotics or physiological serum (control) was administered orally, twice a week, during 5weeks. Sperm were collected from the cauda epididymis, and their total number, motility, kinematics, morphology, and acrosome integrity were assessed in recently collected samples and after a 60-min in vitro incubation. Results showed a higher percentage of normal sperm in both experimental groups, with fewer head abnormalities than in the control. Differences were found among groups in the morphometry of sperm heads, being more elongated in mice treated with probiotics. Sperm from probiotic-treated mice showed similar total motility when compared to the controls, although the proportion of progressively moving sperm and their vigor of motility were lower. Sperm swimming descriptors were measured with a CASA system. Velocity parameters were similar among groups whereas linearity was higher in mice treated with the commercial probiotic. These results suggest that the administration of probiotics may increase the proportion of sperm with normal morphology and lead to modifications in sperm head shape that may enhance sperm swimming. Studies using a longer administration period would be useful in further characterizing the effect of these probiotic mixtures on sperm quality and fertilization capacity.

Nanocarrier-Based Drug Delivery Systems Targeting Kidney Diseases.

The potential applications of nanotechnology in the medical field have become increasingly recognized in recent years. Nanocarriers have emerged as a versatile tool, offering a wide range of applications due to their unique properties. In addition to the targeted drugs delivery, nanocarriers have also proven to be extremely effective in imaging and diagnostics. Continuous advances in nanotechnology have paved the way for innovative solutions to complex challenges in human health, shaping the future of nanotechnology and its applications. By exploring different types of nanoparticles, this review delves into the different characteristics that can be tailored to enhance their kidney access. Although the structural complexity of the kidney may prevent nanocarriers passage, optimization of nanocarrier characteristics such as shape, size, charge, and surface modifications may overcome these barriers, allowing for targeted delivery. By harnessing the potential of nanoparticles, researchers aim to develop targeted and efficient therapies that can address various kidney-related disorders. This review highlights the promising advancements in nanotechnology and their potential impact on improving the therapeutic outcomes for several kidney diseases.

Treatment of polyethylene microplastics degraded by ultraviolet light irradiation causes lysosome-deregulated cell death

BackgroundMicroplastics (MPs), plastic particles < 5 mm in size, are prevalent in the environment, and human exposure to them is inevitable. To assess the potential risk of MPs on human health, it is essential to consider the physicochemical properties of environmental MPs, including polymer types, size, shape, and surface chemical modifications. Notably, environmental MPs undergo degradation due to external factors such as ultraviolet (UV) rays and waves, leading to changes in their surface characteristics. However, limited knowledge exists regarding the health effects of MPs, with a specific focus on their surface degradation. This study concentrates on cytotoxic MPs with surface degradation through UV irradiation, aiming to identify the mechanisms underlying their cell toxicity.ResultsPolyethylene (PE) and surface-degraded PE achieved through UV light irradiation were employed as model MPs in this study. We explored the impact of PE and degraded PE on cell death in murine macrophage cell line RAW264.7 cells and human monocyte cell line THP-1 cells. Flow cytometric analysis revealed that degraded PE induced programmed cell death without activating caspase 3, while non-degraded PE did not trigger programmed cell death. These findings suggest that degraded PE might induce programmed cell death through mechanisms other than caspase-driven apoptosis. To understand the mechanisms of cell death, we investigated how cells responded to degraded PE-induced cellular stress. Immunofluorescence and western blotting analyses demonstrated that degraded PE induced autophagosome formation and increased p62 expression, indicating inhibited autophagy flux after exposure to degraded PE. Furthermore, degraded PE exposure led to a decrease in acidic lysosomes, indicating lysosomal dysregulation. These results imply that degraded PE induces lysosomal dysfunction, subsequently causing autophagy dysregulation and cell death.ConclusionsThis study unveils that UV-induced degradation of PE results in cell death attributed to lysosomal dysfunction. The findings presented herein provide novel insights into the effects of surface-degraded MPs on biological responses.

TFE Terpolymers: Once Promising - Are There Still Perspectives in the 21st Century? Part II: Processing, Properties, Applications.

Tetrafluoroethylene (TFE) terpolymers have emerged as advantageous substitutes for polytetrafluoroethylene (PTFE). Therefore, they are being considered as alternatives to PTFE in many application areas. The advantages of TFE terpolymers include their facile processability at elevated temperatures, their solubility in some polar organic solvents, their inertness against aqueous acids, aqueous bases and a large number of mostly nonpolar organic solvents, their low dielectric constant, their low refractive index as well as useful electro- and thermochemical properties. This review on TFE terpolymers focuses on their processing including shaping and surface modification as well as on selected properties including wettability, dielectric properties, mechanical response behavior, chemical stability, and degradability. Applications including their use as elastomeric sealing material, liner and cladding layer as well as their use as material for membranes, microfluidic devices, photonics, photovoltaics, energy storage, energy harvesting, sensors, and nanothermitic composites will be discussed. The review concludes with a discussion of the future potential of TFE terpolymers and scientific challenges to be addressed by future research on TFE terpolymers.

Enhancing Heat Storage Capacity: Nanoparticle and Shape Optimization for PCM Systems

ABSTRACTPhase change material (PCM)‐based heat storage systems utilize the absorption or release of latent heat during a phase change of the storage material to store thermal energy. Nevertheless, the effectiveness of these systems is restricted by the shape and structure of their confinement, as well as the heat conductivity of the storage material. This work investigates a novel method to enhance the effectiveness of PCM systems by concurrently utilizing two techniques: the inclusion of nanoparticles and the alteration of the system's geometry. Introducing nanoparticles enhances the thermal conductivity of the storage medium while altering the shape, which improves heat transfer efficiency by adjusting the surface area available for heat exchange. RT‐35 was tested for use in latent heat thermal energy storage systems for space heating and cooling. With a melting point of 35°C, RT‐35 was chosen to moderate building temperatures by storing and releasing thermal energy for space heating and cooling. The results indicate that using nanoparticles and adjusting shape can greatly enhance the effectiveness of PCM systems. By incorporating Al2O3 nanoparticles, the melting time of the PCM was reduced by 20% compared to the pure PCM, and it is more efficient than the best case of shape modification. These findings indicate that including nanoparticles and modifying the shape are effective methods to improve the performance of heat storage devices. This technology's potential surpasses this study's limits and can be utilized in diverse applications, including solar thermal energy storage, district heating and cooling, and industrial process heat.

Plant development: The role of SPL9 in age-dependent sculpting of leaf shape

A time-dependent mechanism mediated by SPL9 highlights how age-related growth reprogramming influences leaf shape modifications in simple- and complex-leaved, related plants. Extending cell proliferation and delaying differentiation drives the mechanism, offering insights into the shared developmental processes underlying leaf form diversification.

Control point modifications that preserve the Pythagorean–hodograph nature of planar quintic curves

Although planar Pythagorean–hodograph (PH) curves are compatible with the standard Bernstein–Bézier representations, freely modifying the control points will compromise their PH nature. The present study focuses on identifying control point displacements that ensure a given planar PH curve remains a PH curve. In particular, for planar quintic PH curves r(t), t∈[0,1] it is shown that finitely-many simultaneous displacements of two control points yield modified quintic PH curves, identified as the solutions of quadratic and cubic equations. As a more practical approach, modification of PH quintics in canonical form with r(0)=0 and r(1)=1 by the displacement of a single interior control point is considered, with the remaining interior control points being used to minimize a measure of deviation from the original PH quintic. As illustrated by several examples, this approach provides an efficient and intuitive means of effecting reasonable shape modifications within the space of planar quintic PH curves.

Scar/WAVE drives actin protrusions independently of its VCA domain using proline-rich domains

Cell migration requires the constant modification of cellular shape by reorganization of the actin cytoskeleton. Fine-tuning of this process is critical to ensure new actin filaments are formed only at specific times and in defined regions of the cell. The Scar/WAVE complex is the main catalyst of pseudopod and lamellipodium formation during cell migration. It is a pentameric complex highly conserved through eukaryotic evolution and composed of Scar/WAVE, Abi, Nap1/NCKAP1, Pir121/CYFIP, and HSPC300/Brk1. Its function is usually attributed to activation of the Arp2/3 complex through Scar/WAVE's VCA domain, while other parts of the complex are expected to mediate spatial-temporal regulation and have no direct role in actin polymerization. Here, we show in both B16-F1 mouse melanoma and Dictyostelium discoideum cells that Scar/WAVE without its VCA domain still induces the formation of morphologically normal, actin-rich protrusions, extending at comparable speeds despite a drastic reduction of Arp2/3 recruitment. However, the proline-rich regions in Scar/WAVE and Abi subunits are essential, though either is sufficient for the generation of actin protrusions in B16-F1 cells. We further demonstrate that N-WASP can compensate for the absence of Scar/WAVE's VCA domain and induce lamellipodia formation, but it still requires an intact WAVE complex, even if without its VCA domain. We conclude that the Scar/WAVE complex does more than directly activating Arp2/3, with proline-rich domains playing a central role in promoting actin protrusions. This implies a broader function for the Scar/WAVE complex, concentrating and simultaneously activating many actin-regulating proteins as a lamellipodium-producing core.

Effect of Ferrite Core Modification on Electromagnetic Force Considering Spatial Harmonics in an Induction Cooktop

This study investigates the influence of ferrite shape modifications on the performance and noise characteristics of an induction cooktop. The goal is to optimize the air gap dimensions between ferrites and cookware, enhancing efficiency while managing noise levels. Using finite element method (FEM) simulations, we analyze the spatial distribution of magnetic forces and their harmonics. Eight ferrite shape models were examined, focusing on both outer and inner air gaps. Model #8 (reduced outer air gap) and Model #9 (reduced inner air gap) were experimentally validated. Noise measurements indicated that Model #8 reduced 120 Hz harmonic noise components, while Model #9 increased them due to enhanced excitation forces. Current measurements confirmed that Model #9 achieved higher efficiency, with RMS current reduced to 94.54% of the base model. The study reveals a trade-off between performance and noise: inner air gap reduction significantly boosts efficiency but raises noise levels, whereas outer air gap reduction offers balanced improvements. These findings provide insights for optimizing induction cooktop designs, aiming for quieter operation without compromising efficiency.

Innovative Approaches to Expansion Loop Design for Enhanced Piping System Durability

Expansion loops are critical components in piping systems, designed to manage stress caused by thermal expansion and contraction, thereby ensuring the system&amp;apos;s durability and safety. This study investigates innovative approaches to optimizing expansion loop design, focusing on improving the performance and reliability of piping systems under various operational conditions. The research examines multiple configurations, including alterations in loop length, shape modifications, and the incorporation of additional loops, to assess their impact on stress distribution within the system. While the primary focus of this study is on static stress analysis, transient operational factors, such as water hammer, were also considered in the analysis to provide a more comprehensive understanding of the loop configurations&amp;apos; performance under various conditions. The findings demonstrate that while increasing the loop length can effectively reduce stress, alternative designs, such as double loops or modified shapes, offer superior stress management, particularly in space-constrained environments. The study concludes that optimal expansion loop design should accommodate thermal expansion and provide robustness against potential transient effects, contributing to a more reliable piping system. These insights provide valuable guidelines for the design and optimization of piping systems across various industrial applications.

Co3O4 nanoparticles synthesized with rotten-grape extract for use in supercapacitors and oxygen evolution devices

Phytochemicals in grape fruit juice have never been considered as potential sources of surface modification, shape modification, and energy storage. In our study, we demonstrate the hydrothermal synthesis of Co3O4 nanostructures from grape fruit extracts. X-ray diffraction analysis revealed that Co3O4 nanostructures exhibit a cubic phase, while Fourier transform infrared spectroscopy identified several functional groups. An analysis of Co3O4 nanostructures using a scanning electron microscope revealed that uniformly distributed nanoparticles of Co3O4 were trapped in the carbon content of the spices during calcination. UV–visible spectrometer analysis of Co3O4 nanostructures reveals a wide range of optical bands. It was found that one mL of grape fruit juice provided the lowest optical band gap of 2.51 eV for Co3O4 nanostructures. Nanostructures of Co3O4 were studied under alkaline conditions for use in supercapacitors and oxygen evolution reactions. An aqueous solution containing 1 mL of assisted Co3O4 nanostructures exhibited an overpotential of 290 mV at a current density of 10 mA cm−2 in 1 M KOH. In addition, they showed a Tafel slope of 80 mV dec−1. When dissolved in 3 M KOH electrolyte, grape fruit juice assisted Co3O4 nanostructures showed a specific capacitance of 867 F/g at 1.5 A/g in 3 M KOH aqueous solution. A specific capacitance retention percentage of about 101.1 % was achieved after 40000 galvanic charge-discharge cycles. It has been shown that the total photochemistry of biomass waste can be tuned and enhanced to enhance the functional properties of nanostructures derived from rotten grape fruit extract in order to develop functional materials with high performance for a wide range of applications.

Influence of Labyrinth Side Weir Shape Modification on the Hydrodynamic Performance: Experimental and Numerical Study

Influence of Labyrinth Side Weir Shape Modification on the Hydrodynamic Performance: Experimental and Numerical Study

Evaluating the effect of frigate hangar shape modifications on helicopter recovery using piloted flight simulation

Turbulent ship airwakes can present a major challenge for a pilot landing a helicopter to the ship. A recent study has proposed modifications to the hangar of a simple ship, the SFS2, to improve the air flow over the deck. To assess the effect of the proposed hangar modification on the helicopter and pilot, the unsteady air flow over the modified ship has been computed using time-accurate CFD, and then integrated with a full-motion flight simulator for a pilot to conduct deck landings to the original and modified ship geometries in wind speeds from 30 kt to 50 kt. The effectiveness of the proposed modification was assessed through pilot workload ratings for the landing task, and by recording pilot control inputs and helicopter states. The study has shown that there are some benefits from the hangar modifications. In the headwind the helicopter was deemed to be at the safe limit at 50 kt when operating to the original SFS2, while the limit was not reached in the 50 kt wind for the modified ship. In an oblique wind, the safe wind speed limit was found to be 40 kt for the original ship and 50 kt for the modified version. Although the improvements are not substantial, they do represent a positive outcome.

Membrane-Nanoparticle Interactions: The Impact of Membrane Lipids.

The growing field of nanotechnology presents opportunity for applications across many sectors. Nanostructures, such as nanoparticles, hold distinct properties based on their size, shape, and chemical modifications that allow them to be utilized in both highly specific as well as broad capacities. As the classification of nanoparticles becomes more well-defined and the list of applications grows, it is imperative that their toxicity be investigated. One such cellular system that is of importance are cellular membranes (biomembranes). Membranes present one of the first points of contact for nanoparticles at the cellular level. This review will address current studies aimed at defining the biomolecular interactions of nanoparticles at the level of the cell membrane, with a specific focus of the interactions of nanoparticles with prominent lipid systems.

Influence of Glycerol on the Surface Morphology and Crystallinity of Polyvinyl Alcohol Films.

The structure and physicochemical properties of polyvinyl alcohol (PVA) and PVA/glycerol films have been investigated by Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), thermogravimetry/differential thermal analysis (TG/DTA), and advanced scanning probe microscopy (SPM). In the pure PVA films, SPM allowed us to observe ribbon-shaped domains with a different frictional and elastic contrast, which apparently originated from a correlated growth or assembly of PVA crystalline nuclei located within individual PVA clusters. The incorporation of 22% w/w glycerol led to modification in shape of those domains from ribbon-like in pure PVA to rounded in PVA/glycerol 22% w/w films; changes in the relative intensities of the XRD peaks and a decrease in the amorphous halo in the XRD pattern were also detected, while the DTA peak corresponding to the melting point remained at almost the same temperature. For higher glycerol content, FT-IR revealed additional glycerol-characteristic peaks presumably related to the formation of glycerol aggregates, and XRD, FT-IR, and DTA all indicated a reduction in crystallinity. For more than 36% w/w glycerol, the plasticization of the films complicated the acquisition of SPM images without tip-induced surface modification. Our study contributes to the understanding of crystallinity in PVA and how it is altered by a plasticizer such as glycerol.

Fe2+-Dominated Relaxometric Properties of Iron Oxide Nanoparticles as MRI Contrast Agents.

Iron oxide nanoparticles (IONPs) have garnered significant interest as magnetic resonance imaging (MRI) contrast agents due to their exceptional magnetic properties and biocompatibility. Toward more precise diagnosis of diseases, the relaxometric properties of IONPs have become a key research focus. Despite extensive studies on structural factors such as size, morphology, surface modification, crystalline phase, and aggregation state, the correlation between the intrinsic structure and relaxometric behavior remains unclear, particularly for ultrasmall IONPs. To address this issue, we carefully compared IONPs with identical size, shape, and surface modification and found out strong correlations among the content of Fe2+ ions, oxygen vacancies, and the relaxometric properties. By optimizing the reaction system, ultrasmall IONPs showing outstanding relaxometric performance, with longitudinal relaxivity up to 9.0 mM-1 s-1 and transverse relaxivity up to 28.5 mM-1 s-1, were successfully obtained. These results underscore the pivotal role of Fe2+ in the relaxometric properties of IONP-based MRI contrast agents.