Parallel Grooves Research Articles

Gross Anatomical, Histological, Histochemical and Scanning Electron Microscopic Examination of Glandular Stomach of Chinese Goose (Anser cygnoides)

Background: The digestive system is responsible for the intake, conversion and absorption of nutrients and the elimination of wastes from the body in order to provide the necessary energy for the continuation of vitality and functions. The aim of this study was to examine the glandular stomach of the Chinese goose (Anser cygnoides) by histological, histochemical and scanning electron microscopic methods. Methods: The glandular stomachs of 12 (6 males and 6 females) healthy adult Chinese geese (Anser cygnoides) were used in the study. The tissues taken were subjected to routine histological procedures. Result: Gross anatomically, it was seen that the Proventriculus was a fusiform or spindle-shaped organ, extending along the median plane between the esophagus and the muscular stomach. Scanning electron microscopic (SEM) observations revealed that the glandular stomach surface of Chinese goose (Anser cygnoides) contained many mucosal folds. Parallel grooves and proventricular gland openings were observed between these folds. Histologically, it was observed that the glandular stomach wall of Chinese goose (Anser cygnoides) consisted of four layers: tunica mucosa, submucosa, tunica muscularis and tunica serosa. The tunica mucosa was observed to have lamina epithelialis, lamina propria and lamina muscularis sublayers. Single layer prismatic cells secreting mucus were found in the lamina epithelialis layer. These cells showed local Alcian Blue (AB) pH:2,5 positive reaction. Lamina muscularis consisted of longitudinal smooth muscle fiber bundles. Compound, branched tubular glands were observed in the submucosal layer. Again, a regional AB positive reaction was observed in the lumen-facing parts of the tubular glands. Periodic acid Schiff (PAS) positive reaction was noted in the basal parts of the tubular glands. In Gordon-Sweet (GS) staining method, reticular threads easily distinguished in all areas where connective tissue present.

Simulation and mechanism analysis of fretting wear of parallel groove clamps in distribution networks caused by Karman vortex vibration

PurposeThe phenomenon of friction and wear in parallel groove clamps under wind vibration in 10 kV distribution networks represents a significant challenge that can lead to their failure. This study aims to elucidate the wear mechanism of parallel groove clamps under wind-induced vibration through simulation and experimentation.Design/methodology/approachFLUENT software was used to simulate the flow around the conductor and the parallel groove fixture, and the Karman vortex street phenomenon was discussed. The stress fluctuations of each component under breeze vibration conditions were investigated using ANSYS, and fretting experimentations were conducted at varying amplitudes.FindingsThe results demonstrate that the impact of breeze vibration on the internal stress of the parallel groove clamps is considerable. The maximum stress observed on the lower clamping block was found to be up to 300 MPa. As wind speed increased, the maximum vibration frequency was observed to reach 72.6 Hz. Concurrently, as the vibration amplitude increased, the damage in the contact zone of the lower clamping block also increased, with the maximum contact resistance reaching 78.0 µO at a vibration amplitude of 1.2 mm. This was accompanied by a shift in the wear mechanism from adhesive wear to oxidative wear and fatigue wear.Originality/valueThis study presents a comprehensive analysis of the fretting wear phenomenon associated with parallel groove clamps under wind vibration. The findings provide a reference basis for the design and protection of parallel groove clamps.

Laser-patterning bacterial nanocellulose for cell-controlled interaction

The interfacial topography of biomaterials has been identified as a major biophysical regulator of cell behavior and function, a role played through the interplay with biochemical cues. In this work, we demonstrate the potential of laser as a versatile technology for the direct fine-tuning of the topography of Bacterial nanocellulose (BNC) with bioinspired topographies and micropatterns on a cell size scale. Two lasers were used, with different wavelengths—IR (CO2, 10600 nm) and UV (tripled Nd: YVO4, 355 nm) —attempting to reproduce the Pitcher-plant topography and to create cell-contact guidance patterns, respectively. Different topographies with parallel grooves featuring a 20–300 μm period were generated on the BNC surface with high fidelity and reliability of the generated microstructures, as demonstrated by 3D optical profilometry and scanning electron microscopy. Moreover, it was demonstrated by X-ray photoelectron spectroscopy that laser processing does not result in detectable chemical modification of BNC. The developed anisotropic microstructures can control cell behavior, particularly regarding morphology, alignment, and spatial distribution. Thus, this proof-of-concept study on the high-resolution laser patterning of BNC opens new perspectives for the development of cell-modulating laser-engineered BNC interfaces, scaffolds, and other advanced medical devices, which can potentially broaden the application of BNC in the biomedical field.

Assessing predator–prey interactions during the Late Triassic of India from bite marks on Hyperodapedon (Archosauromorpha, Rhynchosauria)

ABSTRACT Multiple cranial and mandibular remains of Hyperodapedon huxleyi known from the lower part of the Upper Triassic Maleri Formation were examined to reveal distinct bite marks. These were identified as punctures based on their circular or oval or elliptical outline and deep penetration into the cortical bone, and were found associated with several bone-damaging features such as radiating fractures, serrated boundaries, and collapsed bony surface. In addition, bite traces or drag marks in the form of parallel grooves with U-shaped cross sections are identified. The bite marks are compared with dental morphology of varied Late Triassic carnivores of India, and the probable producers are suggested to be phytosaurs and dinosauriforms. The Maleri trophic structure or food web is reconstructed to reveal interconnectedness between different animal groups, unconfined feeding habits of the animals where the predators were inclined towards opportunistic feeding rather than a niche-based dietary habit. The study highlights the significance of bite marks in the reconstruction of ancient paleoecosystems.

A comparison of static and rotordynamic characteristics for two types of liquid annular seals with and without helical grooved stator

Less leakage is a benefit of parallel grooved liquid seals (labyrinth seals). But researches show that the liquid seal with parallel grooves on the rotor harms the rotor stability. The seal with helical grooves on stator performs well in terms of rotordynamics, and its leakage is sensitive to the rotating speed. To make use of the advantages of both seals and improve seal stability, based on the Smooth-stator/Parallel Grooved-rotor (SPG) liquid seal, a Helical Grooved-stator/Parallel Grooved-rotor (HGPG) liquid seal is designed. To evaluate two liquid seals’ leakage, rotordynamic characteristics and drag power loss, a transient computational fluid dynamics-based method is employed. This method is based on the multi-frequency elliptical-orbit rotor whirling model and the mesh deformation technique. The published experimental data of the leakage and rotordynamic force coefficients for an SPG liquid seal are used to validate the accuracy and dependability of the current method. Seal leakage and force coefficients are presented and compared for the SPG liquid seal and the HGPG liquid seal at various pressure drops. The influences of parallel groove depth on the leakage and rotordynamic properties for the HGPG liquid seals at two rotational speeds (2000, 6000 r/min) are analyzed. The numerical findings demonstrate that the novel HGPG liquid seal has a lower leakage flow rate (by ∼22.3%) than the traditional SPG liquid seal. There is an optimal parallel groove depth that minimizes leakage. The presented novel HGPG liquid seal significantly improves rotordynamic stability, due to the similar effective stiffness and the obviously larger positive effective damping. Reducing parallel groove depth can increase the positive effective damping. In terms of leakage and rotordynamic characteristics, the novel HGPG liquid seal is a better seal design for liquid turbomachinery.

Enhancement-mode Ga2O3 FETs with an unintentionally doped (001) β-Ga2O3 channel layer grown by metal-organic chemical vapor deposition

High-quality unintentionally doped (UID) (001) β-Ga2O3 homoepitaxial films were grown on native substrates through metalorganic CVD. The surface parallel grooves were repaired under low temperature and pressure conditions, reaching the surface roughness of 2.22 nm and the high electron mobility of 74.6 cm2/Vs. Enhancement-mode MOSFETs were fabricated on the UID β-Ga2O3 film, showing a positive turn-on threshold gate voltage of 4.2 V and a breakdown voltage of 673 V. These results can serve as a reference for (001)-oriented lateral Ga2O3 power transistors and may contribute to the development of Ga2O3 power devices.

Superhydrophobic surface preparation and tribological properties of Ti-1023 alloy with parallel groove

Superhydrophobic surfaces are increasingly vital in materials science due to their exceptional properties such as water repellency, self-cleaning, and corrosion resistance. However, fabricating these surfaces on metal substrates poses significant challenges, including the need for precise control over micro- and nano-structures and ensuring their durability under mechanical and environmental stresses. This study introduces a novel fabrication method for superhydrophobic surfaces on Ti-1023 alloy utilizing nanosecond laser ablation followed by chemical modification with perfluorodecyltriethoxysilane. This technique allows precise microstructural adjustments and enhanced durability. Our findings demonstrate that a groove spacing (GS) of 100 μm optimizes the water contact angle to 162.8° and the water sliding angle to 7.8°. Meanwhile, a GS of 200 μm minimizes the coefficient of friction to 0.176 under starved-water lubrication conditions. These advancements demonstrate the method’s effectiveness in reducing wear and friction, and highlight its potential in aerospace and other high-performance industries.

Fog water collection of harp-like single smooth and texturized filaments under field conditions

Harp-like arrangements of filaments have been proposed as a more efficient alternative to cross-linked screens for fog water collection. We investigate the fog capture capabilities of both smooth and texturized single vertical nylon threads under field conditions. Redefining the Stokes number in terms of the wetted string and the pinning drop geometry allowed the average fog water collection efficiency to be described using a physically based droplet impaction model with acceptable fit (NSE = 0.614; RMSE = 0.093). In addition, rugosity of the filaments was found to affect the long-term fog water yield (up to 41 % lower), while parallel grooves along the filaments maximised the fog collection, with 51 % improvement, under real field conditions.

Identifying and documenting osseous trauma from shark attacks by post mortem CT examination and autopsy.

A 15-year-old male was attacked by a large white shark while surfing. CT examination revealed an above-knee amputation of the right lower extremity with stripping of soft tissues from the groin distally. 3-dimensional volume rendering did not show any fragments of shark teeth but did reveal linear gouges, areas of shaving of cortical bone and an inverted 'V'-shaped defect at the distal margin of the femoral shaft. At autopsy these injuries were confirmed in addition to areas with fine parallel cross-striations matching the marginal serrations of the teeth of a white shark. Thus, while post mortem CT with 3-dimensional reconstruction at high resolution can show the nature and number of the bony injuries following shark attack, it is complimented by pathological examination which may find fine parallel grooves from teeth serrations. Post mortem 3-dimensional volume rendering may also help to find or exclude fragments of teeth, and silicone casting may provide a permanent record of bone lesions.

Cyclic strain alters the transcriptional and migratory response of scleral fibroblasts to TGFβ

In glaucoma, scleral fibroblasts are exposed to IOP-associated mechanical strain and elevated TGFβ levels. These stimuli, in turn, lead to scleral remodeling. Here, we examine the scleral fibroblast migratory and transcriptional response to these stimuli to better understand mechanisms of glaucomatous scleral remodeling. Human peripapillary scleral (PPS) fibroblasts were cultured on parallel grooves, treated with TGFβ (2 ng/ml) in the presence of vehicle or TGFβ signaling inhibitors, and exposed to uniaxial strain (1 Hz, 5%, 12–24 h). Axis of cellular orientation was determined at baseline, immediately following strain, and 24 h after strain cessation with 0° being completely aligned with grooves and 90° being perpendicular. Fibroblasts migration in-line and across grooves was assessed using a scratch assay. Transcriptional profiling of TGFβ-treated fibroblasts with or without strain was performed by RT-qPCR and pERK, pSMAD2, and pSMAD3 levels were measured by immunoblot. Pre-strain alignment of TGFβ-treated cells with grooves (6.2 ± 1.5°) was reduced after strain (21.7 ± 5.3°, p < 0.0001) and restored 24 h after strain cessation (9.5 ± 2.6°). ERK, FAK, and ALK5 inhibition prevented this reduction; however, ROCK, YAP, or SMAD3 inhibition did not. TGFβ-induced myofibroblast markers were reduced by strain (αSMA, POSTN, ASPN, MLCK1). While TGFβ-induced phosphorylation of ERK and SMAD2 was unaffected by cyclic strain, SMAD3 phosphorylation was reduced (p = 0.0004). Wound healing across grooves was enhanced by ROCK and SMAD3 inhibition but not ERK or ALK5 inhibition. These results provide insight into the mechanisms by which mechanical strain alters the cellular response to TGFβ and the potential signaling pathways that underlie scleral remodeling.

Effect of Micro-Texture on Cutting Performance of PCBN Cutter

The research aimed to delve into the intricate relationship between surface microtexture and the cutting performance of a PCBN cutter. In pursuit of this goal, the study implemented three distinct microtextures on the forefront of the turning tool, each of diverse forms. To comprehensively understand the impact, a 3D model was meticulously constructed for simulation purposes. Subsequently, these microtextures were translated into physical form on the tool’s exterior using laser machining, enabling the researchers to conduct real turning experiments. The experimental phase was designed with precision, maintaining consistent environmental conditions across all tests. The primary focus of these experiments was to investigate the forces generated during the turning process. Additionally, the study explored the stress distribution on the tool’s surface and evaluated the texture of the workpiece after machining. The findings revealed valuable insights into the role of microtextures in altering stress dynamics. Specifically, a tool featuring microtexture on its front exhibited a reduction in stress values, strategically shifting the stress focus from the tool’s tip to the microtexture location on the forefront. Moreover, concerning the texture of the workpiece’s surface post-machining, the tool with parallel groove microtexture demonstrated a noteworthy 21% decrease in surface roughness. The study highlighted the pivotal role of surface microtextures in shaping the performance of a lathe tool. These microtextures were identified as agents capable of modifying the immediate friction between the tool and its chip, thereby diminishing surface friction, cutting force, and post-machining surface roughness. The operational stability of lathe machining was also enhanced through these microtextures. Notably, the microtexture characterized by parallel grooves demonstrated a significant improvement in chip-guiding capacity by aligning with the chip flow direction during cutting. The presented research provided a nuanced understanding of how microtextures on a lathe tool’s surface can be strategically employed to optimize cutting performance, offering potential advancements in the field of machining technology.

Parallel Grooved Microstructure Manufacturing on the Surface of Si3N4 Ceramics by Femtosecond Laser.

Machining special microstructures on the surface of silicon nitride ceramics helps improve their service performance. However, the high brittleness and low fracture toughness of silicon nitride ceramics make it extremely difficult to machine microstructures on their surface. In this study, a femtosecond laser is used to machine parallel grooved microstructures on the surface of silicon nitride ceramics. The effects of the laser polarization angle, laser single pulse energy, scanning line spacing, and laser scan numbers on the surface morphology and geometric characteristics of grooved microstructures are researched. It is found that a greater angle between the direction of the scanning path and laser polarization is helpful to obtain a smoother surface. As the single pulse energy increases, debris and irregular surface structures will emerge. Increasing the laser scan line spacing leads to clearer and more defined parallel grooved microstructures. The groove depth increases with the increase in the scan numbers. However, when a certain number of scans is reached, the depth will not increase further. This study serves as a valuable research foundation for the femtosecond laser processing of silicon nitride ceramic materials.

Self-Reinforced PTLG Copolymer with Shish Kebab Structures and a Bionic Surface as Bioimplant Materials for Tissue Engineering Applications.

Green and biodegradable materials with great mechanical properties and biocompatibility will offer new opportunities for next-generation high-performance biological materials. Herein, the novel oriented shish kebab crystals of a novel poly(trimethylene carbonate-lactide-glycolide) (PTLG) vascular stent are first reported to be successfully fabricated through a feasible solid-state drawing process to simultaneously enhance the mechanical performance and biocompatibility. The crystal structure of this self-reinforced vascular stent was transformed from spherulites to a shish kebab crystal, which indicates the mechanical interlocking effect and prevents the lamellae from slipping with a significant improvement of mechanical strength to 333 MPa. Meanwhile, it is different from typical biomedical polymers with smooth surface structures, and the as-obtained PTLG vascular stent exhibits a bionic surface morphology with a parallel micro groove and ridge structure. These ridges and grooves were attributed to the reorganization of cytoskeleton fiber bundles following the direction of blood flow shear stress. The structure and parameters of these morphologies were highly similar to the inner surface of blood vessels of the human, which facilitates cell adhesion growth to improve its proliferation, differentiation, and activity on the surface of PTLG.

Comparison of turning process performance using modified cutting inserts under minimum quantity lubrication

ABSTRACT While machining of high-strength alloy steel materials, poor surface quality and decreased tool life are result by an increase in the cutting zone temperature close to the machining region. To overcome this, surface texture with green manufacturing environment is an alternate path to enhancing machining performance. In the present work, novel Parallel Grooved Textured Tools (PGT) was developed and studied the performance of so developed tools. Further, the Untextured Tool (UT) and PGT performance was compared while machining EN24 alloy steel under Minimum Quantity Lubrication (MQL) condition. It was perceived from result that textured tools reduced the cutting temperature (CT), rake wear (RW), flank wear (FW), surface roughness (Ra) and cutting force (CF) up to 18.96%, 18.79%, 24.31%, 12.69%, and18.96% respectively compared to UT.

Fabrication and characterization of aluminum foam reinforced with nanostructured γ-Al2O3 via friction stir process for enhanced mechanical performance

AbstractThis study focuses on the fabrication and characterization of aluminum foam reinforced with nanostructured γ-Al2O3, utilizing AA5083 plates. The fabrication process involved the integration of TiH2 foaming agent particles and reinforcing nanoparticles via the friction stir process (FSP), resulting in the creation of precursor specimens. Subsequently, a separate foaming stage was conducted within a laboratory furnace. The integration of these particles was achieved through the machining of parallel grooves in a single aluminum plate. The initial phase of the experimental study focused on investigating the effect of varying amounts of the foaming agent. Large-scale foams were then produced, achieving a medium porosity of 70%. Electro-discharge machining was employed to prepare specimens for compression testing to analyze their stress–strain response. The results revealed a plateau stress of 27 MPa, a relative Young’s modulus of 4.44 × 10−3, and an energy absorption close to 17 MJ/m3 at 50% strain. Significantly enhanced plateau stress was observed in the manufactured reinforced aluminum foam compared to similar foams produced through conventional methods.

Erratum to: Bio-inspired Filter Design Based on Vortex Control Mechanism of Parallel Groove Structure

Erratum to: Bio-inspired Filter Design Based on Vortex Control Mechanism of Parallel Groove Structure

Boiling Heat Transfer On Biphilic Surfaces With Arrays Of Grooves

Experiments were carried out on biphilic surfaces made using technology consisted in the deposition (105℃) of fluorinated methoxysilane on a copper surface with arrays of grooves preliminarily created by laser ablation, as a result of which deposition the grooves became superhydrophobic. Grooves were two types: parallel grooves and groove lattice. Size of grooves was 30-43 um, pitch for parallel grooves was 1-1,5 mm and for grove lattice – 1 mm. The experiments were carried out on distilled water at atmospheric pressure. For all surfaces, a significant intensification of heat transfer has been achieved, compared with a smooth copper surface. It was shown, that boiling heat transfer depend only from pitch between grooves for both types of grooves. Dependence of heat transfer coefficient from size of grooves was not observed. Most efficient type of surfaces was groove lattice with smallest pitch.

Micro texturing and laser irradiation, two stimulus of growth and differentiation to neural like cell on the PMMA polymer

Nerve injuries and neurodegenerative disorders remain serious challenges due to the poor results of nerve cell regeneration. The most promising treatment for such injuries is treatments based on stimulating cells to grow and differentiate stem cells in that area into nerve cells, but there are obstacles in controlling the growth and differentiation into fully functional nerve cells and research is ongoing to overcome these obstacles. In this study, polymethyl methacrylate (PMMA) and its laser modified surfaces were used for cell culture and differentiation into neuron-like cells. In order to show the differentiation of PC12 cells into neuron-like cells, the expression levels of the neuronal markers Map2 and Synapsin-1 were examined. The results showed the growth of PC12 on raw PMMA was increased significantly compared to the control group and micrometric parallel grooves lead to a significant difference in cell growth compared to raw PMMA. Also, the simultaneous irradiation of laser to the cell cultured on PMMA caused more cell adhesion on the surface, faster growth and differentiation of PC12 into neuron-like cells.

Aging of the sea urchin Centrostephanus rodgersii using demi-pyramid microstructure

We investigate a novel aging method that utilizes parallel ridges and grooves on the surface of demi-pyramids of the sea urchin Centrostephanus rodgersii. Analysis of marginal increments from sea urchins tagged with oxytetracycline confirmed that ridges form in the mid to late Austral spring, as seawater begins to warm. After known periods of up to three years, counts of ridges from tagged sea urchins showed that the ridges were formed annually. Differences between observed and expected counts of ridges were mostly related to readers’ inability to distinguish adjacent ridges at the growing margin of the demi-pyramid. This resulted in a higher probability of underestimating age for individuals ≥ 6 yr. Counts of the ridges on the same demi-pyramid by the same reader, and comparisons among different readers, provided estimates of random error and bias. Estimates of aging error and bias in distinguishing ridges were modeled and used to estimate ‘true’ age and age structure. Maximum estimated age was 27 yr but most individuals were estimated to be 10–15 yr. We discuss the relevance of our findings to the fishery and the broader applicability of our method to correct ages estimated from other hard parts in marine species.

Performance tests on triple composite mesh-groove-powder wicks in a visualizable flat-plate heat pipe

Two types of novel triple composite mesh-groove-powder wicks are proposed and tested in a visualizable flat-plate heat pipe. The powders are only added in the evaporator in the triple composite wicks to increase the capillarity therein. Outside the evaporator is the mesh-groove wick, with a layer of 200-mesh copper screen sintered over parallel grooves, which has been shown to exhibit high permeability and anti-gravity ability. The first type (Triple A) is to add powders in the mesh-groove wick at the evaporator section, while the second type (Triple B) contains an evaporator with only copper powders. The parallel grooves have a semi-elliptic cross-section with a width of 0.18 mm and a depth of 0.075 mm. According to visualization, the powders in the mesh-groove evaporator appear to increase the flow resistance and prompt partial dry-out in some grooves at high heat loads. The experiment results for the Triple B wick with a powder-only evaporator demonstrate a maximum heat load (Qmax) 20 % higher than that for the double mesh-groove wick at the horizontal orientation, with evaporator resistances also slightly higher. However, the Triple A wick, with powders added in the mesh-groove evaporator, displays a slightly lower Qmax than the original mesh-groove evaporator due to the excessive flow resistance associated with powder-filled meshed grooves.