Labyrinth Structure Research Articles

Effect of prefatigue-induced persistent slip bands on the strength-ductility match in -oriented Cu single crystals

To explore the effect of persistent slip bands (PSBs) formed during cyclic loading on the static mechanical behavior of materials, [1‾12]-oriented Cu single crystals are selected as target materials, and the tensile behavior of Cu single crystals prefatigued to the stress saturation stage at different plastic shear strain amplitudes (γpl) and the corresponding microstructures, surface deformation features and fracture morphologies are systematically studied. The results show that the formation of few soft PSB ladder-like structures in hard dislocation veins during prefatigue deformation at γpl = 3.7 × 10−4 below the plateau region of cyclic stress-strain (CSS) curve can promote a synchronous improvement of strength and ductility (SISD) compared with the unfatigued crystal. As γpl increases to a lower value of 9.0 × 10−4 within the plateau region, the strength and ductility reduce sharply compared with the case at γpl = 3.7 × 10−4 due to more concentrated plastic deformation caused by a high volume fraction of prefatigue-induced PSBs. With continuously increasing γpl to a higher value of 2.3 × 10−3 within the plateau region, non-uniform dislocation distribution in labyrinth structures and the short spacing between labyrinth walls as well as the fine dislocation cells formed during tension jointly give rise to a slight increase in strength and ductility compared with the crystal prefatigued at γpl = 9.0 × 10−4. As γpl is increased to the level beyond the plateau region, the ductility and ultimate tensile strength continuously increase, resulting from the co-existence of wider deformation bands and dense dislocation walls.

Sustainable water sterilization by nano-ZnO using anisotropic polysaccharide columns derived from agro-waste stalk

The escalating demand for clean water and proliferation of microbial contamination in water have challenged ecosystems and human health safety. ZnO NPs are widely used as environmental restoration agents, but their efficacy in water decontamination is hindered by low biological toxicity. In order to enhance its sterilization efficiency, we propose a top-down strategy utilizing the unique maze structure of corn stalk pith (CSP) as a germ trapper for ZnO. The in-situ delignified CSP offers abundant active sites for the adsorption of Zn2+, exhibiting the typical behaviors of monolayer, physisorption, endothermicity, spontaneity, and randomness. This adsorption behavior exerts an influence on microscopic morphology of the composite column, consequently resulting in alterations to antibacterial properties. The results show that the hybrid column fabricated under the Zn2+ initial dosage of 1.00 mol/L at 30 h for 40 °C, possesses such optimal features as stacked grain-shaped ZnO NPs of 669.3 mg/g loading amount with adhesion coefficients of 0.73 ∼ 0.86 for bacterial microparticles. Consequently, the assembled bio-filter can eliminate E. coli and S. aureus as high as 99.7 % and 96.5 % respectively, attributed to CSPP labyrinth structure to enhance pathogen capture from water and facilitate ZnO-mediated inactivation. The collective findings emphasize the viability of agro-waste stalks as bio-filters for water purification.

Constructing labyrinth structure in molecularly imprinted composite membranes for efficiently separating acteoside

Molecular imprinted composite membranes (MICMs) had attracted much attention in the field of selective separation for bioactive components of natural products. However, it remained a challenge to improve the separation performance of MICMs. Herein, multi-chamber carbon cubes (MCCBs) were synthesized and introduced into polyvinylidene fluoride (PVDF) powders to construct labyrinth structure in molecularly imprinted composite membranes (LMICMs), which were used for efficiently separating acteoside (ACT). The constructed labyrinth structure had complex multidimensional transport routes to trap abundant ACT molecules in LMICMs, thereby improving the rebinding capacities and permselectivity of LMICMs. Meanwhile, the prepared MCCBs with multi-chamber structure can provide a great accommodation space, improving the rebinding capacities of LMICMs. In addition, the labyrinth structure with the large interface resulted in the creation of numerous ACT-imprinted sites and cavities (ACT-ISC) in LMICMs, thus increasing the permselectivity of LMICMs to ACT. Importantly, it was no surprise that large rebinding capacity (154.74 mg/g), excellent rebinding selectivity (4.52) and high permselectivity (14.88) were successfully achieved. It was of great value to design LMICMs with labyrinth structure for efficiently separating of bioactive components from natural products.

Dual-network PVA fiber-doped cellulose aerogel with labyrinth structure for low and medium frequency acoustic and flame retardant applications

Dual-network PVA fiber-doped cellulose aerogel with labyrinth structure for low and medium frequency acoustic and flame retardant applications

Thickness- and Field-Dependent Magnetic Domain Evolution in van der Waals Fe3GaTe2.

The discovery of room-temperature ferromagnetism in van der Waals (vdW) materials opens new avenues for exploring low-dimensional magnetism and its applications in spintronics. Recently, the observation of the room-temperature topological Hall effect in the vdW ferromagnet Fe3GaTe2 suggests the possible existence of room-temperature skyrmions, yet skyrmions have not been directly observed. In this study, real-space imaging was employed to investigate the domain evolution of the labyrinth and skyrmion structure. First, Néel-type skyrmions can be created at room temperature. In addition, the influence of flake thickness and external magnetic field (during field cooling) on both labyrinth domains and the skyrmion lattice is unveiled. Due to the competition between magnetic anisotropy and dipole interactions, the specimen thickness significantly influences the density of skyrmions. These findings demonstrate that Fe3GaTe2 can host room-temperature skyrmions of various sizes, opening up avenues for further study of magnetic topological textures at room temperature.

Bonding strength enhancement of a 30-wt.% GF/PET–2024 aluminium alloy joint by synergistic action of multi-scale mechanical interlocking and multiplex H-bonding

In this study, micro-scale cellular and nano-scale labyrinth structures were obtained on the surface of A2024 aluminium alloy adherends through ultrasonic-aided corrosion using an FeCl3 etchant solution to significantly enhance the mechanical interlock of it and a 30-wt.% glass-fibre-enhanced polyethylene terephthalate substrate. The tensile shear strength of the 30-wt.% GF/PET–A2024 joint was increased to 31.84 MPa. The subsequent treatment of an appropriate amount of KH-892/PVA transformed the surface of the aluminium alloy from hydrophobic to hydrophilic to significantly improve its wettability. Furthermore, this treatment generated multiplex hydrogen bonding of O–H⋯O⋯H–N at the interface, further improving the tensile shear strength of the joint up to 50.94 MPa, which is significantly higher than the values obtained using exiting methods. The tensile shear tests of a ring-shaped insulator specimen according to GB 7251-87 verified the improved fracture work equation herein and the bonding strength enhancement of the 30-wt.% GF/PET–A2024 aluminium alloy joint treated by ultrasonic-aided corrosion with an FeCl3 etchant solution and pre-coating of an appropriate amount of KH-892/PVA.

Unveiling the Intricacies of the Inner Ear Anatomy: Novel 3D-Printed Model for Detailed Visualization and Functional Demonstrations.

This research aimed to print realistically detailed and magnified three-dimensional models of the inner ear, specifically focusing on visualising its complex labyrinth structure and functioning simulation. Temporal bone computed-tomography data were imported into Mimics software to construct an initial three-dimensional inner-ear model. Subsequently, the model was amplified and printed with precision using a three-dimensional printer. Five senior attending physicians evaluated the printed model using a Likert scale to gauge its morphological accuracy, clinical applicability and anatomical teaching value. The printed inner-ear model effectively demonstrated the intricate internal structure. All five physicians agreed that the model closely resembled the real inner ear in shape and structure, and simulated certain inner-ear functions. The model was considered highly valuable for understanding anatomical structure and disorders. The three-dimensionally printed inner-ear model is highly simulated and provides a valuable visual tool for studying inner-ear anatomy and clinical teaching, benefiting otologists.

Langerhans cell histiocytosis involving the temporal bone with destruction and subsequent reossification of the bony labyrinth boundaries.

With an incidence between 1-9/100 000 per year, Langerhans cell histiocytosis (LCH) is a rather rare disease from the hemato-oncologic disease spectrum (Hayes et al. 2009). The tumorlike disease with proliferation of histiocytic cells may manifest as localized to one organ or disseminated with infiltration of a wide variety of organs. Approximately 25-30 % of these cases show involvement of the temporal bone (Ni et al. 2017). With vertigo persisting for three years, chronic mastoiditis, and acute progressive hearing loss bilaterally (r > l) for three weeks, a 41-year-old woman presented at an emergency department. The DVT showed extensive bony destruction of large parts of the temporal bone on both sides, involving the vestibular organ, the cochlea, and the internal auditory canal. To confirm the suspicion of a systemic inflammatory process, a PE was performed from the mastoid with bioptic confirmation of an LCH. Systemic therapy was initiated. Post-therapeutic imaging showed almost complete remission with reossification of the preexisting defect zones and the internal auditory canal and labyrinth structures again showed bony margins. Clinically, there was an improvement of the vegetative symptoms with remaining bilateral sensorineural hearing loss. LCH of the temporal bone is a rare and often misdiagnosed disease due to its nonspecific clinical presentation. Awareness of temporal bone LCH and its occurrence in adults is essential for accurate and consistent diagnosis. · LCH is a rather rare disease from the hemato-oncological spectrum. · Affection of the temporal bone, especially such an extensive one (as in this case report), is rather atypical in adulthood. · Use of systemic therapy resulted in remission. · There was complete reossification of the osseous structures post-therapy. · A cochlear implant was able to be implanted to compensate for hearing loss.

Improving Hydraulic Performance of Drip Irrigation Emitters Through CFD Analysis

A drip irrigation system delicately nourishes plant roots by gently delivering water drop by drop, ensuring minimal water loss due to runoff or evaporation. This method allows soil particles ample time to absorb and retain the water, promoting optimal plant hydration. To enhance the efficiency of drip irrigation, a mesmerizingly detailed 3D solid model of a drip emitter was meticulously crafted using cutting-edge SolidWorks software, revolutionizing the irrigation system's performance. CFD simulation technique is used to understanding the internal flow behavior and optimum pressure inside the in -line drip irrigation emitters. Their labyrinth structures of channels are main cause of change in flow behavior and optimum pressure in the drip irrigation emitters. Standard k-ɛ model and Enhanced wall function are used to simulate the flow behavior in labyrinth channels. Key findings are the efficiency of triangular channel is greater than the other channels (rectangular, trapezoidal and circular) based on analysis of flow rate. The value of Discharge coefficient of these channels from CFD simulation present a relationship of kCircular>kTrapezoidal>kRectangular>kTriangular. When the channel shape is smooth (like a circular channel) than the higher value of k. The efficiency of triangular channel is greater than the other channels (rectangular, trapezoidal and circular) based on analysis of flow rate. Discharge is increased by 76%, 68.42%,66.67% and 39.39% for circular channel, Trapezoidal channel, rectangular channel and Triangular Channel respectively for pressure range of 1.02m of water head to 10.2m of water head.

Computational design of a smoke detector with high sensitivity considering three-dimensional flow characteristics

Early fire detection is essential for preventing catastrophic events, and fire detectors play a critical role in ensuring fire safety. Among the various types of fire detectors, photoelectric smoke detectors are widely used because of their ability to detect smoke at an early stage. The present study investigates the effects of changes in flow directions and inlet size on the smoke detection ability of a photoelectric smoke detector by conducting computational fluid dynamics (CFD) simulations. The results indicated that when the flow direction changes, the components in the optical chamber may hinder the smoke inflow and increase the detector activation time. Moreover, the smoke inlet size was found to affect the carbon monoxide concentration inside the chamber. The velocity magnitude distributions confirmed the correlation between the smoke velocity in the labyrinth structures entering the optical chamber and the detection ability of the smoke detector. These findings suggested that when optimizing the performance of a smoke detector, flow direction, inlet size, and amount of smoke introduced into the optical chamber should be considered. The current study suggested the modified design of the smoke detector to have superior detection ability in both directions compared to the base case in terms of activation time.

Reconfigurable labyrinth structures as low frequency sound absorbers

In this work, we designed a metamaterial labyrinth structure as sound absorber for low frequency. The labyrinth structure is made by stacking disks with holes or openings at its front and back surfaces, and these openings are linked by air channels within the disks. Five disks with different opening locations were designed and fabricated using 3D printing. The disks were stacked and rotated with respect to each other, connecting different inlets and outlets, to form various patterns of labyrinth. Using a two-microphone impedance tube, the absorption coefficient of these stacks, ranging from one to five disks, was measured. The results show that a stacked structure with more disks enhances the absorption at low frequencies. As each disk was designed with twelve possible rotational positions, a stack of three disks will give more than 8000 combinations. It is not practical to conduct experiments to measure the absorption coefficient of all possible combinations. Hence, a neural network was used to fit and predict the absorption. Using the fitted neural network model, we would be able to predict the combinations to give best absorption and target frequency band. [Work supported by Singapore MOE Tier 1 Grant A-0009119-00-00.]

Superb microplastics separation performance of graphene oxide tuned by laser bombardment

Microplastics have been identified as a significant environmental threat to aquatic ecosystems and human health. Consequently, there is an urgent need for efficient separation methods for small-sized MPs. In this study, a super-hydrophilic graphene oxide (GO) membrane is successfully prepared by facilely depositing GO on a microfiltration substrate, without introducing any surface modification materials, especially nanoparticles, which may cause secondary pollution. Laser bombardment reduces GO lamellar size (23.6% of its original size) and creates an abundance of defects and undulating wrinkles, enabling the deposited GO membrane to have more and shorter pathways for water. As a result, the filtration permeance for 10 μm polyvinyl chloride reaches up to 3396 L m−2 h−1 bar−1, a 1–2-order-of-magnitude enhancement compared to the unirradiated GO membrane, and is also superior to most nanoparticle-modified GO membranes. Simultaneously, the labyrinth structure endows the membrane with a high filtration efficiency of approximately 99% for the majority of MPs. This excellent performance remains virtually unchanged after repeated use. The integration of outstanding separation effects and health safety presents opportunities for practical applications in long-term MP-in-water separation.

The Influence of Magnetic Fields on Electrophoretic Processes in Magnetic Colloids with Different Stabilization Mechanisms

Electrophoretic nanostructuring is a promising approach for the creation of functional surfaces and active layers. The potency of this approach may be further enhanced by additional factors of various natures, such as magnetic fields. In this work, we have studied the process of electrophoresis in thin layers of water- and kerosene-based magnetic liquids and the effect of additional magnetic fields on the occurring processes. It was found that the electrophoresis process can be significantly affected by inhomogeneous magnetic fields. The possibility of compensating electrophoresis processes in such systems by means of inhomogeneous magnetic field influence was shown. Structural changes in magnetic colloids on hydrocarbon bases under the influence of an electric field have been studied. The role of electrohydrodynamic flows arising in this process is considered, and the influence of the magnetic field on the configuration of the formed labyrinth structure is studied. The dependence of the threshold value of the electric field strength corresponding to the emergence of the structure on the temperature and additionally applied magnetic field has been established. The obtained results could contribute to the development of an original method for determining the charge and magnetic moment of a single nanoparticle.

Numerical modeling of internal flows in tanks with baffles

The proposed article presents the materials of experimental and mathematical studies of internal inertial flows of an incompressible liquid during its fluctuations in tanks. An analysis of modern problems related to the harmful effect of liquid resonant splashing on tank structures, as well as on the trajectory and nature of the object movement itself with the liquid, was carried out. The use of damping baffles and guide devices in similar closed flows allows to fundamentally change the structure of internal flows, reducing gradients of shock pressures in flows, as well as redistributing the main liquid inertial effects. Numerical modeling of such flows qualitatively confirms the results of experimental studies and allows us to build a rather complex three-dimensional development picture of fluctuations in fluid flows. In addition to the use of the damping baffles structures, it is proposed to make the plane of baffles perforated with different degrees of permeability due to the diameter of the holes and their number. The effect of hydraulic resistance occurs when flow energy is lost due to overcoming artificial obstacles in the form of holes of small diameter. Thus, the shock effects of the flow on the walls of the tank are predicted to have a smaller amplitude and duration. The use of the proposed dampers labyrinth structures allows to control the force effects of the liquid only by hydraulic means and thus reduce the number and dimensions of the internal guide devices.

Heat transfer characteristics of double pipe heat exchanger having externally enhanced inner pipe

An investigation on enhancement of heat transfer is carried out for a double pipe heat exchanger in which the outer wall of the inner pipe is provided with circumferential labyrinth passages. Rectangular and triangular cavities with fixed labyrinth tooth thickness, height, and pitch are considered and the effect of added labyrinth structures on the heat transfer characteristics is discussed. A two-dimensional steady numerical simulation is carried out using ANSYS-FLUENT software. The flow Reynolds number equals to 20 000 and 43 000 for the hot and cold fluids, respectively, while other fluid properties are constant. From the numerical analysis carried out in this work, it is identified that the added labyrinth passages in the heat exchange surface improve the heat transfer rate and can reduce the length of the heat exchanger. Numerical predictions agree well with the results obtained from the experiment conducted.

Locomotor behavior and hearing sensitivity in an early lagomorph reconstructed from the bony labyrinth.

The structure of the bony labyrinth is highly informative with respect to locomotor agility (semicircular canals [SCC]) and hearing sensitivity (cochlear and oval windows). Here, we reconstructed the agility and hearing sensitivity of the stem lagomorph Megalagus turgidus from the early Oligocene of the Brule Formation of Nebraska (USA). Megalagus has proportionally smaller SCCs with respect to its body mass compared with most extant leporids but within the modern range of variability, suggesting that it was less agile than most of its modern relatives. A level of agility for Megalagus within the range of modern rabbits is consistent with the evidence from postcranial elements. The hearing sensitivity for Megalagus is in the range of extant lagomorphs for both low- and high-frequency sounds. Our data show that by the early Oligocene stem lagomorphs had already attained fundamentally rabbit-like hearing sensitivity and locomotor behavior, even though Megalagus was not a particularly agile lagomorph. This is likely because Megalagus was more of a woodland dweller than an open-habitat runner. The study of sensory evolution in Lagomorpha is practically unknown, and these results provide first advances in understanding the primitive stages for the order and how the earliest members of this clade perceived their environment.

Dynamically adjustable directional acoustic radiation based on non-uniform cylindrical labyrinth structure

In this work, a cylindrical four-channel non-uniform labyrinth structure is constructed. The ring shaped metamaterial designed by using the rotational anisotropy of the structure can control sound wave and achieve dynamically adjustable directional sound radiation. The cylindrical non-uniform labyrinth structure comprised of four channels has dipole resonance characteristic. At the dipole resonance frequency, sound waves can radiate from the openings of two sector channels that occupy a large proportion. At this time, the cylindrical non-uniform labyrinth structure can be approximately regarded as a dipole sound source. For the cylindrical uniform labyrinth structure, the sound transmission property will not change as it rotates around its center. However, when the cylindrical non-uniform labyrinth structure rotates around its own center, the position of the dipole sound source and the direction of the radiated sound wave also change. Placing a point sound source in the center of the circular metamaterial composed of 18 non-uniform labyrinth structures, and adjusting the rotation angle of the circular non-uniform labyrinth structure so that each structure lies in the conductive or cut-off state, the propagation of the point sound source in all directions can be controlled. The propagation characteristics of these structures are utilized to achieve dynamically adjustable directional sound radiation. In addition, the influence of the rotation angle of the cylindrical non-uniform labyrinth structure on the transmitted sound wave is studied, and the switching effect of the non-uniform cylindrical labyrinth structure in the constructed sound source system is explored, which provides a new idea for constructing simple directional radiation acoustic equipment.

Iron island films on sapphire grown by pulsed laser deposition with in situ electrical resistance monitoring

Iron island films were grown on sapphire by pulsed laser deposition with in situ electrical resistance control, which made it possible to precisely determine the percolation transition. Four growth stages can be distinguished: initial nucleation, independent island growth, ripening with channel formation, and island coalescence into a labyrinth structure. The morphology of the iron island films corresponded to these stages, depending on the time and deposition rate at a given temperature. At growth temperatures of T ≥ 350 °C, the percolation thickness exponentially depended on the temperature. The electrical response time τ of the system to a single pulse was<1 s, and the temperature dependence of 1/τ was linear in Arrhenius coordinates with a slope corresponding to an activation energy of 0.41 eV. The dependence of the film thickness and island diameter on the pulse frequency before the onset of the percolation transition reached a maximum, which can be explained by two competing factors: diffusion stimulation owing to the high kinetic energy of the incident particles and an increase in the number of initial nuclei in the substrate regions without islands.

Electric field control of labyrinth domain structures in core-shell ferroelectric nanoparticles

In the framework of the Landau-Ginzburg-Devonshire (LGD) approach, we studied the possibility of controlling the polarity and morphology of equilibrium domain structures by a homogeneous external electric field in a nanosized ferroelectric core covered with an ultrathin shell of screening charge. Under certain screening lengths and core sizes, the minimum of the LGD energy, which consists of Landau-Devonshire energy, Ginzburg polarization gradient energy, and electrostatic terms, leads to the spontaneous appearance of stable labyrinth domain structures in the core. The labyrinths evolve from an initial polarization distribution consisting of arbitrarily small randomly oriented nanodomains. The equilibrium labyrinth structure is weakly influenced by details of the initial polarization distribution, such that one can obtain a quasicontinuum of nearly degenerate labyrinth structures, whose number is limited only by the mesh discretization density. Applying a homogeneous electric field to a nanoparticle with labyrinth domains, and subsequently removing it, allows inducing changes to the labyrinth structure, as the maze polarity is controlled by a field projection on the particle polar axis. Under specific conditions of the screening charge relaxation, the quasistatic dielectric susceptibility of the labyrinth structure can be negative, potentially leading to a negative capacitance effect. Considering the general validity of the LGD approach, we expect that an electric field control of labyrinth domains is possible in many spatially confined nanosized ferroics, which can be potentially interesting for advanced cryptography and modern nanoelectronics.

Acoustic wavefront manipulation via transmission-type labyrinth structure

In this work, a transmission-type labyrinth structure (LS) is proposed to construct subwavelength acoustic functional metasurfaces, through which various desirable acoustic wavefront manipulation can be achieved in a broadband from 2,700 Hz to 3,900 Hz. By utilizing the excellent guiding property of LS, an invisibility cloak is designed to shield the target scattering body in the transmitted field. In addition, gradient metasurfaces composed of several LSs with different phase responses are constructed to obtain broadband beam deflection and focusing. Moreover, binary coding approach is adopted to further simplify the design philosophy of the metasurfaces by taking advantage of only two kinds of LS with opposite phase responses. Numerous wavefront manipulations including acoustic splitting beam and self-bending beam can be realized by using corresponding coding sequences. Our work provides a solution for multifunctional acoustic wavefront manipulation in a broadband, which may have potential applications in acoustic communication, detection and holography.