Irregular Surface Research Articles

3D analysis of crack propagation in nuclear graphite using DVC coupled with finite element analysis

The initiation and propagation of cracks within nuclear graphite components compromise the lifespan of advanced gas-cooled reactors and even lead to safety incidents. A thorough understanding of fracture properties in nuclear graphite is crucial for the effective management and design of graphite structural components. In this work, an in-situ test of a double cleavage drilled compression (DCDC) specimen was conducted using X-ray tomographic imaging to fully analyze the 3D crack propagation behavior in IG-11 nuclear graphite. “Subvolume Splitting” digital volume correlation (SS-DVC) was employed to accurately quantify the displacement fields surrounding the crack. The entire 3D crack propagation and crack surface around the crack front were precisely captured through 3D imaging processing of the gray level residual (GLR) field. Additionally, crack opening displacements (CODs) and stress intensity factors (SIFs) were determined using finite element (FE) analysis with extended finite element method (XFEM). Experimental results indicate that although mode I crack remains predominant throughout the whole process, complex crack propagation exists around the crack front. The utilization of irregular crack surfaces in FE analysis helps to obtain refined displacement fields and accurate SIFs of the crack front. This work provides comprehensive insights into crack propagation and reveals the influence of complex crack morphology on SIF calculations, facilitating accurate prediction of structural integrity and rational design of graphite components.

Exploring the Tribological Behavior and Surface Characteristics of Polymethyl-Methacrylate/Hydroxyapatite (PMMA/HA) Composites: Investigating the Effect of Hydroxyapatite Weight Ratios on Wear Performance, Surface Roughness, and Hardness

This study conducts an analysis of the tribological characteristics of polymethyl-methacrylate (PMMA) composites reinforced with varying weight ratios of hydroxyapatite (HA) nanoparticles. It encompasses a systematic assessment of both hardness and surface roughness using the Shore-D hardness testing method and profilometer measurements, respectively. The results reveal a correlation between the HA nanoparticles weight ratio and hardness, indicating an increase in HA nanoparticles weight ratio corresponded to enhanced hardness. Moreover, higher HA nanoparticles weight ratios result in rougher surfaces, impacting composite performance. Specifically, the composite containing 5%-HA exhibited a Rq of 6 µm, which incrementally rose to 6.3 µm for the 10%-HA composite and significantly increased to 11.1 µm for the 15%-HA composite. Increasing HA weight ratios led to higher Rz values: 28 µm for 5%-HA, 35.1 µm for 10%-HA, and 72.5 µm for 15%-HA, indicating greater surface irregularities. The wear rates and friction coefficients are examined under applied forces ranging from 5 to 15 newtons across three distinct HA weight ratios (5%, 10%, and 15%). The results show a decreasing trend in wear rates with increasing weight ratios of HA, evidenced by weight loss rates of 0.0052 gr, 0.0011 gr, and 0.006 gr for samples S.1, S.2, and S.3, respectively, under a 15 N applied force. The friction coefficient analyses highlight complex dependencies on sliding distance, applied force, and HA weight ratio. Statistical tests, such as One-way analysis of variance (ANOVA) and effect size calculations, confirm significant applied force effects on friction coefficients, offering insights for optimizing PMMA/HA composite performance in biomedical applications.

Identification of microRNAs expressed in an animal model of periodontal disease and their impact on pathological processes

MicroRNAs represent a class of small RNAs that act to silence genes post-transcriptionally by inhibiting the translation of target messenger RNAs, and this study aimed to understand how miRNAs influence the set-up of periodontal disease. Periodontitis was induced by inserting a ligature into the left first mandibular molar in a rat model, which was kept for the entire 56 days-time of experiment. After 56 days post-periodontitis induction, the histopathological analysis showed an apical extension of the junctional epithelium, with areas of hyperplasia, exocytosis, and a mixed inflammatory infiltrate with a predominance of neutrophils, lymphocytes, and eventual plasma cells in the deeper layers. The cement surface showed areas of irregularity, covered by cementoblasts and irregular surfaces, confirming the set-up of periodontitis. In the sequencing analysis, 26,404 genes were identified, with 132 reaching statistical significance. Among genes with a statistical difference, 18 were found to encode for microRNAs. The identified microRNAs are primarily involved in bone remodeling by acting on fibroblast growth factors, and collagen production. These outcomes demonstrate a signaling role in bone resorption, which is consistent with the histopathological observations that show the installation of inflammation with epithelial migration and the beginning of the repair process, with cementum resorption. The disclosure of how miRNAs may influence the maintaining of periodontal disease will help the development of new dental materials for the prophylaxis and treatment of alveolar bone resorption.

Investigation on the microscopic mechanism of curdlan with different strengths formed by heating

SummaryIn this study, temperature‐dependent changes in the molecular conformation of curdlan were investigated using differential scanning calorimetry (DSC), microscopic observation, particle size analysis and molecular dynamics (MD) simulation. The DSC results showed that the gel formation temperature of curdlan is related to the glass transition temperature (Tg). The results of microscopic observation and particle size analysis showed that the curdlan particles swelled with increasing temperature, and the original rough and irregular surface morphology gradually became relatively smooth. The MD results show that the weak gel is the result of hydrogen bonds and hydrophobic interaction, whereas the strong gel is less affected by hydrogen bonds, and hydrophobic interaction is the main driving force.

Exploring the Link: Trichostasis Spinulosa and Its Association with Early Phymatous Rosacea

Introduction: Rosacea is a chronic inflammatory skin condition with several clinical subtypes, including phymatous rosacea, which is distinguished by thickened skin, enlarged pores, and irregular surface nodularities, primarily affecting the nose. This manuscript aims to explore the underrecognized connection between early to moderate phymatous rosacea and trichostasis spinulosa (TS), a follicular disorder characterized by the retention of multiple telogen hairs. Methods: A total of consecutive 13 patients with initial phymatous changes and black dilated openings were enrolled. Detailed dermatological assessments, including dermoscopy, were conducted to identify and confirm trichostasis spinulosa. Dermoscopy of the black openings confirmed the presence of hair tufts emerging from dilated follicular openings and plugs. Patients underwent minor procedures using a comedo extractor to remove the hair bundles. Results: All extracted follicular units showed typical characteristics of trichostasis spinulosa, including bundles of telogen hairs surrounded by a sebokeratinous plug. Conclusion: We postulate that the fibrotic processes characteristic of phymatous rosacea may promote the development of TS. Recognizing TS as an early indicator of phymatous rosacea could help prevent disease progression.

The NACOB multi-surface walking dataset

Walking is a fundamental aspect of human movement, and understanding how irregular surfaces impact gait is crucial. Existing gait research often relies on laboratory settings with ideal surfaces, limiting the applicability of findings to real-world scenarios. While some irregular surface datasets exist, they are often small or lack biomechanical gait data. In this paper, we introduce a new irregular surface dataset with 134 participants walking on surfaces of varying irregularity, equipped with inertial measurement unit (IMU) sensors on the trunk and lower right limb (foot, shank, and thigh). Collected during the North American Congress on Biomechanics conference in 2022, the dataset aims to provide a valuable resource for studying biomechanical adaptations to irregular surfaces. We provide the detailed experimental protocol, as well as a technical validation in which we developed a machine learning model to predict the walking surface. The resulting model achieved an accuracy score of 95.8%, demonstrating the discriminating biomechanical characteristics of the dataset’s irregular surface gait data.

Application of texture mapping algorithm in irregular surface art images

Application of texture mapping algorithm in irregular surface art images

Irregular surface temperature monitoring in liver procurement via time-vertex signal processing

The liver viability monitoring during its procurement is critical to guarantee the safe liver transportation. Traditionally, the viability is assessed by taking invasive biopsy on the liver surface. Recently, the noninvasive thermal images of liver surface have been used as an alternative assessment way. Researchers have proposed monitoring and classification approaches based on the thermal images. Existing works have demonstrated the importance of the temporal variation or the spatial variation of the thermal images to the viability monitoring. However, there is no prior work to leverage the graph structure of the spatio-temporal processes for the viability monitoring. In this paper, we propose a time-vertex signal processing framework for the irregular thermal data of the pure liver region monitoring. In particular, we extract features of irregular thermal data based on the joint Fourier transform (JFT), which is an integration of graph Fourier transform (GFT) and discrete Fourier transform (DFT). The extracted JFT features can accurately reconstruct the thermal images with a limited number of features. Then, we use a non-parametric online change-point estimation method, based on online scan B statistics, to monitor the JFT features without a parametric distribution. Our proposed framework is applied to both simulation and the liver procurement data, and achieves good monitoring performance.

Multiband polarimetric imaging of HD 34700 with SCExAO/CHARIS

Abstract We present Subaru/SCExAO + CHARIS broadband (JHK) integral field spectroscopy of HD 34700 A in polarized light. CHARIS has the unique ability to obtain polarized integral field images at 22 wavelength channels in broadband, as the incoming light is first split into different polarization states before passing though the lenslet array. We recover the transition disk around HD 34700 A in multiband polarized light in our data. We combine our polarized intensity data with previous total intensity data to examine the scattering profiles, scattering phase functions and polarized fraction of the disk at multiple wavelengths. We also carry out 3D Monte Carlo radiative transfer simulations of the disk using MCFOST, and make qualitative comparisons between our models and data to constrain dust grain properties. We find that in addition to micron-sized dust grains, a population of sub-micron grains is needed to match the surface brightness in polarized light and polarized fraction. This could indicate the existence of a population of small grains in the disk, or it could be caused by Mie theory simulations using additional small grains to compensate for sub-micron structures of real dust aggregates. We find models that match the polarized fraction of the data but the models do not apply strong constraints on the dust grain type or compositions. We find no models that can match all observed properties of the disk. More detailed modeling using realistic dust aggregates with irregular surfaces and complex structures is required to further constrain the dust properties.

Injectable natural hydrogel with spatiotemporal self-strengthening, antibacterial and anti-inflammatory properties for treating diabetic wound

Injectable hydrogel dressings provide a promising approach for treating diabetic wounds as they conform to irregular surfaces and foster new tissue development in a moist environment. Nevertheless, post-injection mechanical performance is often mediocre, coupled with inadequate antibacterial protection. Herein, we prepared an injectable hydrogel dressing (CBGT@PDA) consisting of double-network hydrogel (CBGT) and polydopamine nanoparticles (PDA NPs) as a multi-targeted combination therapy system oriented to chronic diabetic wound healing. Efficient enzymatic reactions combined with a slow quaternization procedure regulate the mechanical attributes of injectable hydrogels, offering spatiotemporal self-strengthening and exceptional antibacterial capabilities. The hydrogel system is also equipped with scavenged ROS function, bioadhesion characteristics and remarkable biocompatibility, thus exhibiting high improvement in the healing of the diabetic wound. We believe such injectable hydrogels with spatiotemporal self-strengthening capabilities in both of mechanical and antibacterial properties will provide new insight into the hydrogel-based wound dressing and broaden the application of the bioinspired hydrogels in biomedical fields.

Effect of silver nanochitosan on control of seed-borne pathogens and maintaining seed quality of wheat

Seeds, considered as the foundation of agriculture, are invaded by a broad spectrum of seed-borne pathogens. The current study aimed to control seed-borne fungal pathogens of wheat, Aspergillus flavus and A. niger, by using Ag+ nanochitosan (Ag-NC) for nano-priming of seeds and enhancing seed quality. Nanochitosan (NC) and Ag-NC were synthesized using the gelation method and characterized by UV–vis spectrophotometry, FESEM, EDXS, and HRTEM. NC and Ag-NC showed irregular surface topography with an average particle size of 275 and 325 nm, respectively. Antifungal activity of both the nanoparticles at 0.1, 0.2, 0.3, 0.4, and 0.5 mg/mL revealed that Ag-NC at 0.5 mg/mL has completely terminated the mycelial growth of both pathogens. Malonaldehyde content increased to 77.77% in A. flavus and 82.66% in A. niger when exposed to 0.5 mg/mL Ag-NC. High-intensity fluorescence due to oxidative stress was observed in Ag-NC-treated pathogens. Ultra-structural changes in Ag-NC treated pathogenic spores under SEM displayed pronounced membrane damages. Wheat seeds were nano-primed with NC and Ag-NC at 0.5 mg/mL, and fungal load was examined to evaluate the mitigation of pathogenic stress and its effect on seedling growth promotion activity. Ag-NC priming reduced the fungal load and allowed successful seed germination. Ag-NC priming increased the albumin, gliadin, gluten, and glutenin content along with total phenol, reducing sugar and starch levels. Ag-NC priming increased the overall protein levels traced through SDS-PAGE. Seed priming with Ag-NC promotes seed germination, mean germination time, stress tolerance index, vigour, etc. NC and Ag-NC at 0.5 mg/mL showed no cytotoxic effect on the Human Embryonic Kidney (HEK293) cell line that ensures the nanoparticles are non-toxic. Thus, the synthesized nanoparticles exhibit a dual role in antifungal activity and plant growth promotion.

Highly robust soft-rigid connections via mechanical interlocking for assembling ultra-stretchable displays

Stretchable electronic circuits can seamlessly conform to irregular and dynamic surfaces with high integration. However, current stretchable configurations typically have limited stretchability due to the lack of robust connections between soft interconnects and rigid electronics. Here, we printed highly stretchable metal–polymer conductors on thermoplastic elastomers as interconnects. We developed electronic vests with porous surfaces for rigid electronics and introduced polyester hot-melt adhesives to strengthen connections between soft interconnects and rigid electronics. After thermal bonding, the adhesive penetrates the porous surface of electronic vests, creating a mechanical interlock and providing an adhesion force of 8.34 N/cm for the connection (3× higher than conductive adhesives). Thus, rigid electronics of different sizes and different pin counts can form strong connections to soft interconnects, achieving a maximum strain tolerance of ~700% (10× higher than conductive adhesives). We achieved highly integrated ultra-stretchable displays that can withstand stretching up to 220% without dead pixels.

Development of Epigallocatechin and Ascorbic Acid Dual Delivery Transferosomes for Managing Alzheimer's Disease: In Vitro and in Vivo Studies.

Epigallocatechin-3-gallate (EGCG) and ascorbic acid (AA)-loaded transferosomes (TRANS) were developed for brain delivery. The investigation covered EGCG-TRANS, AA-TRANS, and EGCG-AA-TRANS formulations using the film hydration technique. We analyzed the formed transferosomes to confirm the presence of vesicles loaded with the respective drugs and their performance within a living organism. The sizes of the particles for EGCG-TRANS, AA-TRANS, and EGCG-AA-TRANS were measured correspondingly at 174.2 ± 1.80, 132.7 ± 12.22, and 184.31 ± 9.5 nm. The appearance of diffused rings in the scanning electron microscopic image suggests that the payload has a crystalline structure. The atomic force microscope image displayed minimal surface irregularities, potentially indicating the presence of a lipid layer on the surface. Hemolysis results indicated the safety of the vesicles. The results showed 10.23, 7.21, and 8.20% of hemolysis for EGCG-TRANS, AA-TRANS, and EGCG-AA-TRANS, respectively. In the case of EGCG-AA-TRANS, the release of EGCG was determined to be 61.65% ± 4.61 after 72 h when exposed to phosphate buffer saline (pH 7.4). In vivo studies show a good response against Alzheimer's disease (AD). EGCG-AA-TRANS (82.166%) exhibited a higher percentage of AChE inhibition in comparison to EGCG-TRANS (66.550%) and AA-TRANS (53.466%). Intranasal delivery of EGCG-AA-TRANS resulted in approximately a 5-fold enhancement in memory. Formulation allowed EGCG and AA to accumulate in various organs, including the brain. The results suggest that EGCG-AA-TRANS could be safe and effective for treating AD.

Study on the characteristics of novel fiber extracted from Foxtail palm fruits – A steps towards the sustainable development

This study explores the properties of fibers extracted from the fruits of the Foxtail palm (FPF) and assesses their potential for advancing sustainable development. Antibacterial assays demonstrated that these fibers significantly inhibit the growth of gram-negative bacteria, including Pseudomonas aeruginosa and Salmonella enterica, with inhibition zones of 24 mm and 30 mm, respectively. X-ray diffraction analysis revealed a predominantly crystalline structure, which is crucial for use as reinforcing materials, showing distinct peaks at 20° and 30° diffraction angles that signify the presence of cellulose I. Fourier-transform infrared spectroscopy confirmed the fibers’ complex composition of cellulose, hemicellulose, and lignin, indicated by the presence of hydroxyl, carbonyl, and aliphatic functional groups. Scanning electron microscopy analysis showed a rough and irregular surface texture adorned with numerous microfibrils and cavities, which are beneficial for mechanical interlocking with polymer matrices. The densely arranged cellulose microfibrils, approximately 210 µm in diameter, lend the fibers high tensile strength and stiffness. Although some surface imperfections were observed, the inherent porosity of the fibers facilitates resin absorption, enhancing their reinforcement capabilities in composite materials.

Study of micro texture parameters, optical loss and opt-electrical calculations in CuAlZnO films

In this paper, the CuAlZnO films were deposited by rf-magnetron sputtering in room temperature on glass substrates. In this deposition process, the equilibrium amount of room temperature during deposition of the CuAlZnO films was provided by the flow of cold water at room temperature inside the copper tubes inserted behind the substrate holder. Then they were annealed by an electric furnace in the presence of argon gas for 1 h at different temperatures of 400, 500, and 600 ° C.Micro texture studies of these the CuAlZnO films using the SPIP™ 6.7.4 software, according to ISO 25178–2:2012, in room temperature and using AFM obtained data, were measured. We found that with increasing annealing temperature from 400 to 600 ° C, the uniformity and their mean height of the distribution of scattered nanoparticles on the surface of the CuAlZnO films, on films surface were increased. It can be seen that the CAZnO films annealed at 400 ° C became more irregular surface hence the maximum value of Sq belongs to these films were in about of 0.09674 mm. The core roughness height Sk calculated as a difference between two extreme levels (maximal and minimal) of surface core, for CAZnO films annealed at 500 ° C have maximum value of 0.001537 mm. It can be seen that as deposited CAZnO films have maximum number of high peaks or valleys on their surface. Due to the high polarization of space charges in the top frequency region, the value of log (dielectric loss tan(δ)) in CAZnO films annealed at 500 ° C have maximum value. It was found that CAZO films annealed at 500 ° C have minimum value of surface kurtosis in about of 8.606 mm. In high frequencies, the AC conductivity of CAZnO films annealed at 400 °C has maximum values.

Quantitative Analysis of the Impact of Finishing and Washing Processes on the Roughness of Polyester Fabric.

The roughness of woven fabric surface has so far been mainly investigated as a key characteristic of comfort in contact with the skin. The analysis of roughness can be extended to various contexts and applications, becoming an important tool for understanding how textile materials react in interaction with different finishing agents, as well as for gaining insight into the durability and effectiveness of treatments. This research presents a comprehensive study on the impact of alkaline hydrolysis and chitosan coating on the roughness of polyester woven fabric, utilizing both novel and adapted methods. The study employed contact and optical methods to analyze fabric and fiber surface characteristics, highlighting the significance of roughness profile parameters in understanding material changes post-treatment. The investigation revealed that mechanical action, alkaline medium, washing temperature, and detergent residues contribute to fabric erosion and modification during washing, with chitosan coatings creating pronounced surface irregularities. Comparative analysis showed significant fabric roughness changes post-washing, while fiber roughness changes were treatment specific. Despite initial increases in fiber roughness due to treatments, their durability decreased after washing. These findings emphasize the importance of roughness analysis in optimizing textile finishing processes and washing cycles, impacting both comfort and treatment efficacy.

Elucidation of the pathophysiology of interstitial cystitis/bladder pain syndrome via experimental autoimmune cystitis rat model.

Although the cause of interstitial cystitis/painful bladder syndrome (IC/PBS) remains unknown, autoimmune involvement has been strongly suggested to be a contributing factor. To elucidate the pathophysiology of IC/PBS, we characterized the experimental autoimmune cystitis (EAC) in rats. Adult female Sprague-Dawley rats were divided into the EAC and control groups. The EAC rats were generated by administrating a homogenate of donor rat bladder tissue as a bladder antigen. The characteristics of the two groups were determined by evaluating pain behavior and conducting cystometry, histopathology, and molecular analyses. The EAC rats showed: 1) a decreased paw withdrawal threshold, 2) a reduced intercontraction interval on cystometry, 3) the irregular surfaces of the umbrella cells of epithelium throughout the bladder wall, 4) accumulation of stress granules in the bladder and vascular endothelium, 5)the increased expression of genes related to inflammation and ischemia at the mRNA and protein levels, 6) a significantly increased paw withdrawal threshold with pain treatment, and 7) the induction of glomerulation of the bladder wall, epithelium denudation, and lymphocyte infiltration in the interstitium by bladder distension. These results suggest that the EAC rats showed pain and frequent urination with the overexpression of inflammatory chemokines, reflecting clinical IC/BPS, and the bladder epithelium and vascular endothelium may be the primary sites of IC/BPS, and bladder injury, such as bladder distension, can cause progression from BPS to IC with Hunner lesions.NEW & NOTEWORTHY The experimental autoimmune cystitis model rats showed pain and frequent urination with the overexpression of inflammatory chemokines, reflecting clinical interstitial cystitis/painful bladder syndrome (IC/PBS), and the bladder epithelium and vascular endothelium may be the primary sites of IC/BPS, and bladder injury, such as bladder distension, can cause progression from BPS to IC with Hunner lesions.

Un caso de osteocondroma en la oreja de un gato

In this case report, we aimed to share the clinical and histopathological examination and treatment process of a 6-month-old hybrid cat brought with the complaint of swelling in the medial part of the right auricle. In clinical examination, it was determined that the mass had a hard and irregular surface structure. As a result of the clinical examination, it was decided to completely extirpate the mass and send it to the pathology department. The mass was widely separated from the surrounding tissues and extirpated with the help of cautery. Microscopic examination of the mass revealed that there were chondrocytes among the dense bone cell accumulations and that they formed islands in some areas. As a result of histopathological examinations, it was determined that the suspicious mass was osteochondroma. During the postoperative examinations, it was determined that there was no recurrence or complication in the patient. As a result, it was concluded that this presentation will contribute to the literature since osteochondroma masses are rare in the ear region.

Cellulose cryogel particles for oil structuring: Mixture properties and digestibility

This study evaluated the feasibility of using cellulose cryogel particles to structure liquid oil. To this aim, cryogel particles were prepared by grinding and freeze-drying a hydrogel made from a 5% (w/w) microcrystalline cellulose (MCC) dissolved in aqueous NaOH and coagulated in water. Compared to native MCC, cryogel particles presented a more irregular surface, as detected by scanning electron microscopy. The powder of cryogel particles presented low density (0.25 g cm−3), and high porosity (78%). The obtained particles were mixed with increasing quantities of sunflower oil, from 60 to 80% (w/w) oil, and their capacity to entrap oil forming a semi-solid material was determined. While MCC showed no oil structuring capacity, cellulose cryogel particles mixed with 71–74% (w/w) oil resulted in gel-like materials characterized by 100% oil holding capacity. No oil was released upon temperature increase up to 90 °C. The compressive behavior of these systems revealed no yield point, highlighting a non-spreadable deformation behavior. In these conditions, cellulose cryogel particles likely absorbed oil in their pores, while free oil formed capillary bridges allowing particle interconnections without the formation of a plastic network. Based on these considerations, these materials can be regarded as granular solids. The in vitro gastrointestinal digestion showed that oil structuring by cellulose cryogel particles did not affect the kinetics or the extent of fatty acid release. The proposed oil structuring approach opens promising applications of porous cellulose in foods.

Mechanical performance and anisotropic analysis of rubberised 3D-printed concrete incorporating PP fibre.

The research investigates the effects of substituting sand with rubber particles derived from waste tyres-up to 40% by volume-and the inclusion of polypropylene (PP) fibres. Unlike steel fibres, which can cause operational challenges and surface irregularities in the printing process, PP fibres' flexibility integrates well within the concrete matrix. This integration ensures smooth extrusion and a high-quality surface finish, enhancing the printability of the concrete. The study's findings reveal that including rubber particles and PP fibres impacts the concrete's properties, showing a general decline in compressive and flexural strengths as the rubber content increases. Nevertheless, the PP fibre-enhanced mixtures maintain sufficient structural strength, demonstrating an anisotropic compressive strength above 30MPa and a flexural strength of 4MPa. These results underscore the feasibility of using rubberised 3D-printed concrete with PP fibres in sustainable construction practices, aligning with standards (ACI 318:2018) and contributing to eco-friendly and innovative construction methodologies.