Distribution Of Material Research Articles

Extremely Fast Wicking Self‐Layered Interpenetrating Network Hydrogel for Rapid All Day Collection of Atmospheric Water

AbstractHygroscopic salt hydrogel photothermal composites and related technology are a promising pathway for water harvesting. However, due to the overly cumbersome preparation process, the distribution of the surface photothermal layer is difficult to control and the photothermal efficiency is low. In this paper, a method is proposed to greatly simplify the preparation process of photothermal layer hydrogels and improve their atmospheric water harvesting performance by constructing temperature‐sensitive interpenetrating networks. Due to the decomposition of some reversible hydrated structures in the network during heating and warming, carbon nanotubes move autonomously to form a layered structure with a photothermal effect on the upper surface, which can return to its original state after cooling and remain stable at room temperature or under solar illumination. Compared with hydrogels with general layered structure or overall distribution of photothermal materials, agar/GG/PAM/CNT hydrogel has faster moisture adsorption efficiency and higher desorption efficiency, and during the 24 h continuous sorption–desorption cycle is capable of achieving high water yield of 2.57 Lwater kgsorbents−1 day−1, superior to most recent hydrogel adsorbents. Simplifying the preparation process while maintaining high efficiency, while greatly improving photothermal performance, paves the way for cost‐effective mass production applications for a wide range of hygroscopic salt‐hydrogel photothermal composites.

A Novel Approach of the Viscoelasticity of Axially Functional Graded Bar and Application of Harmonic Vibration Analysis of an Isotropic Beam as Support

The use of smart materials and passive controllers in modern technologies has stimulated the study of vibration in elastic systems with viscoelastic damping. It is also possible to create components with precise material distribution coefficients and distinct properties, such as Functionally Graded Materials. This work investigates the resonant frequency characteristics of a beam supported at its ends by Axially Functionally Graded (AFG) viscoelastic bars using the finite element method. The set of equations governing motion is obtained by assuming Euler–Bernoulli beam theory for the beam and bar theory for the bars using Lagrange’s equations. The material properties of the functionally graded bar is assumed to vary through the length according to the power law distribution. The longitudinal loss factor values are used to define the internal damping coefficient, which is also dependent on the Young’s modulus value varying along the bar. The effects of the length-varying material properties and internal damping of the FG support bars on the force transmission TR and frequency parameters λ are examined in detail. No study has been found in the literature on the vibration of viscoelastic FG bar-supported beams subjected to a harmonic force at the centre point. It is shown that using bars formed with combinations of different materials considering material damping will be useful to keep the vibration level and force transmission at a certain value and control the frequency parameters.

Identification of conservation and restoration materials for iron relics through ultraviolet-induced visible luminescence imaging and pyrolysis-gas chromatography/mass spectrometry

Understanding the previous protection and restoration efforts and the current state of cultural relics is essential before compiling a conservation and restoration plan. The lack of detailed archival records for some early conservation operations, the identification of restoration materials necessitates the use of scientific analytical methods. In this study, the composition and spatial distribution of historical restoration materials on five iron relics were investigated through pyrolysis-gas chromatography/mass spectrometry (Py-GC/MS) and ultraviolet-induced visible luminescence imaging (UVL). The relics studied were iron weight 20791, iron adze head 2335, and iron axe 2334 from the Gansu Provincial Museum, iron sword D0008 from the Zhaotong Municipal Museum, and iron sword 450 from the National Museum of China. All five relics had undergone restoration without accompanying archival records. UVL revealed the distribution of various conservation materials. Notably, two distinct layers of the conservation material were observed on iron axe 2334. Differences in the fluorescence color and intensity of iron sword 450 provided information regarding the sampling strategy. The samples were collected under ultraviolet light emitting diode illumination to ensure representativeness and minimize damage to the relics. Through Py-GC/MS, the coating materials for iron weight 20791 and iron adze head 2335 were identified as boiled tung oil mixed with rosin resin. Iron axis 2334 had a two-layer coating: a base layer of boiled tung oil and a top layer of shellac. The coating material for iron sword D0008 was determined to be paraffin wax. The protective layer of iron sword 450 included multiple materials, including shellac, polystyrene, and bisphenol-A-type epoxy resin. This study confirms that UVL combined with Py-GC/MS serves as an effective technique for analyzing historical restoration materials. UVL guided the selection of representative samples for Py-GC/MS, reducing the time and amount of sampling required and minimizing further damage to the relics. This research provides valuable data for the restoration archives of five iron artifacts, offering a scientific basis for conservators to evaluate conservation methods, devise future conservation strategies, and exclude ineffective conservation materials.

Ultrasonic backscattering measurement of hardness gradient distribution in polycrystalline materials

It is crucial to obtain the internal hardness distribution in polycrystalline materials to evaluate the mechanical performance of components and monitor their service life. Current methods, however, fail to meet the non-destructive evaluation needs for materials with hardness gradient distributions. This paper, based on the principle of grain boundary scattering of ultrasound in polycrystalline materials, combined with the Transverse-to-Transverse Singly-Scattered Response (T-T SSR) theory, proposes an ultrasonic SSR model adapted to hardness gradient distributions. The model elucidates the influence of hardness gradient variations and grain dispersion on ultrasonic scattering. Using DREAM.3D, seven different-scale polycrystalline volumes were constructed to assess the relevance of volume-weighted average grain size and spatial correlation of hardness gradient materials. Finally, induction quenching was applied to 40Cr to induce a gradient hardness distribution internally, followed by ultrasonic backscatter experiments. The results indicate that the theoretical model and the spatial variance of measured signals align well over a relatively long time window. For the specimen with minor curvature, the theoretical hardness distribution obtained by the model is accurate, with an average error of 2.55 % compared to destructive testing data. However, the results for the larger curvature reveal limitations in the model.

Copper-Nickel/SiC composites for applications on contact electrodes

Novel copper-nickel matrix composites reinforced with silicon carbide (SiC) micro particles for metal contact applications were manufactured by powder metallurgy technology and were experimentally characterized. Cu and Cu alloys are commonly used as metal contact for either vacuum, oil, or SF6 in low-voltage circuit breaker devices, but their application in environments with the presence of oxygen is limited due to their tendency to form high-resistance copper oxides. Thus, the addition of Ni as an alloying element provides resistance to both humidity and several corrosive environments and increases the composites' hardness, mechanical strength, and wear resistance. Moreover, SiC was chosen due to its contribution to mechanical strength, mouldability, low production cost, and non-reactive nature at ordinary temperatures. Here, three SiC particle size distributions were considered, and it was found that the composites' physical properties are also dependent on the ceramic loading. After evaluating these properties, two specific SiC concentrations were potentially considered for electrode applications: 10 wt% and 20 wt%. The obtained hardness values are in the range of 55 – 65 HR30T which guarantees the necessary strength without detriment of the contact area whereas the welding is minimized. In addition to a homogeneous particle distribution in the solid material, specific wear resistance of ∼10-5 mm3N-1m-1 and electrical conductivities of ∼20 %IACS were obtained. Considering these parameters, Cu-Ni/SiC composites' performance is not compromised compared to commercial Ag/WC materials commonly used in metal contact applications.

Methodological approaches in vitrification: Enhancing viability of bovine oocytes and invitro-produced embryos.

Cryopreservation of bovine oocytes and embryos is essential for long-term preservation and widespread distribution of genetic material, particularly in bovine invitro embryo production, which has witnessed substantial growth in the past decade due to advancements in reproductive biotechnologies. Among current cryopreservation methods, vitrification has emerged as the preferred cryopreservation technique over slow freezing for preserving oocytes and invitro-produced (IVP) embryos, as it effectively addresses membrane chilling injury and ice crystal formation. Nonetheless, challenges remain and a simple and robust vitrification protocol that guarantees the efficiency and viability after warming has not yet been developed. Furthermore, although slow cooling can easily be adapted for direct transfer, an easier and more practical vitrification protocol for IVP embryos is required to allow the transfer of IVP embryos on farms using in-straw dilution. In addition, the susceptibility of bovine oocytes and embryos to cryoinjuries highlights the need for novel strategies to improve their cryotolerance. This manuscript examines various methodological approaches for increasing the viability of bovine oocytes and IVP embryos during vitrification. Strategies such as modifying lipid content or mitigating oxidative damage have shown promise in improving cryotolerance. Additionally, mathematical modelling of oocyte and embryo membrane permeability has facilitated the rational design of cryopreservation protocols, optimizing the exposure time and concentration of cryoprotectants to reduce cytotoxicity.

Alternative thermal histories of Earth-like planets: Influence of key parameters

The thermal evolution of any planet can be influenced by many factors: the initial temperature profile, the distribution of specific materials within the planet, the existence or lack of a gaseous atmosphere, the effects of early and “late” collision events. Insights concerning the influence of those factors can be obtained by examining solutions to the heat equation, applied to spherical bodies. General trends identified in this work include: 1) Moderate conductive materials contribute to efficiently flatten the temperature gradients, whereas insulating materials promote the preservation of steep temperature gradients. 2) It is not necessary to invoke convection to achieve a relatively flat temperature gradient; moderately conductive materials might achieve the same result without any advective motion involved. 3) Heat transport can take place both outwards and inwards, depending on the initial distribution of temperatures. 4) If the initial temperatures near the center of a planet are low, they will tend to remain low even if heat production takes place at its middle or upper parts. 5) Gradients of temperature near the surface of a planet may not reflect temperature variations at its middle or central parts. 6) Changes of phase exert a strong influence on the evolution of temperature profiles within a planet. 7) Highly insulating atmospheric layers can be important in determining the time of solidification of the upper layer of a magma ocean but not all atmospheres are equally efficient in that respect. As a result, models that give for granted the existence of deep mantle convection on Earth are justified only in the context of models of planet formation that require high initial temperatures; the standard model of a cold solar nebula is not consistent with such deep mantle convective movements.

Reducing defects in hard carbon graphite domain: Employing a fully dynamic bonding with a multi-crosslinked biomass-based binder for enhanced sodium ion storage

Binders are crucial for maintaining the integrity of an electrode and are confronted with the imperative for multifunctionality. Herein, we have developed and synthesized an entirely biomass-based water-soluble binder with outstanding adhesion, conductivity, flowability, and dispersibility for the hard carbon (HC) anode. Specifically, MXene (Ti3C2Tx) reduces the amount of HC graphite domain imperfections, the cross-linked carboxymethyl chitosan (CCS) chain facilitates Na+ movement, and the amphiphilic nature of lignosulfonate (LS) enhances the distribution of active material. As a result, the HC anode achieves an initial coulombic efficiency (ICE) of 88 % and high-capacity retention of 110 % after 100 cycles. This work promotes the progress of green energy in parallel with the promotion of the high-value utilization of biomass.

Composition tracking for collisions between differentiated bodies in REBOUND

Previous research suggests that impacts between planetary embryos and planetesimals during the late stages of planet formation can often determine the percentages of core and mantle material that compose the newly formed planets in a system. Previous studies have attempted to include the composition-changing effects of these collisions in N-body simulations of planet formation, often as post-processing codes. In this paper, we present the Differentiated Body Composition Tracker, a new post-processing tool that uses collisional data collected from the N-body integrator REBOUND to determine the amount of core and mantle material that is transferred between colliding objects and the resulting fragments during an impact. We demonstrate how this code works using the data from 50 REBOUND simulations of planet formation and explore how the parameters in the code affect the core mass fractions of the remaining objects from these simulations. We then investigate how non-uniform distributions of core material across an initial disc affect the final core mass fractions of planets. Under ideal conditions, we find that a combination of giant impacts and planetary embryos enriched in core material could create some of the iron-rich planets that have been discovered.

Developing translational products for adapting evidence-based physical activity interventions in rural communities

The development and distribution of educational materials is a key strategy to support the implementation of evidence-based interventions (EBIs). Rural communities have higher rates of physical inactivity and face higher burden of many diseases that increased physical activity can prevent. To support the translation of a developed physical activity intervention for adults in micropolitan communities (10,000-50,000 people), called Active XXXX, the University of XXXX Prevention Research Center for Rural Health (PRC-RH) created a toolkit and supplemental resources designed to guide implementers through the implementation of the intervention. Through a community-engaged process, the PRC-RH underwent three phases of review and evaluation of the developed products. The first phase involved the Community Advisory Board from the pilot intervention, the second involved the PRC-RH State Advisory Board and public health practitioners from across the state, and the third involved micropolitan leaders and micropolitan health department staff. The feedback received through these three phases resulted in changes to the developed products to improve usability, readability, and clarity. The feedback also resulted in the development of additional materials to further support the implementation of the intervention. The success the PRC-RH experienced in the review process can be attributed to the strong, established partnerships with practitioners across the state who represented a variety of community roles and organizations. The developed materials can be used to improve physical activity rates in rural and micropolitan communities, in turn reducing chronic diseases and improving the quality of life for rural residents.

Management of Logistics Systems to Increase the Competitiveness of a Community Enterprise Processing Herbs from Local Wisdom in Buriram Province, Thailand

The objectives of this research are to study: 1) the operating characteristics of the logistics system, 2) the relationship between logistics system management and competitiveness, and 3) development guidelines to increase the competitiveness of a community enterprise processing herbs from local wisdom in Ban Prue Sub-district, Krasang District, Buriram Province. The population and sample consisted of 30 people. Data were collected using a questionnaire and in-depth interviews, as well as group discussions. Data analysis included statistics such as percentage, mean, standard deviation, Pearson correlation coefficient analysis, and multiple regression analysis. The results of the research revealed that: 1) All aspects of logistics system operations were at the highest level. 2) The relationship between logistics system management and competitiveness was at a moderate level, with customer service and packaging management showing a low level of relationship. And 3) development guidelines to increase competitiveness should focus on producing or developing products to have variety and quality, using local wisdom to create trust, acceptance, and reliability in the long term. It should cover all customer needs and emphasize cost leadership by developing the use of resources in a cost-effective manner and determining production costs based on long experience in business operations to reduce costs and increase efficiency. Rapid response should involve developing production according to orders and delivering products to customers on time using modern technology to speed up production. Testing research hypotheses on raw material procurement, inventory management, transportation, and distribution showed a positive impact while packaging management showed a negative impact on competitiveness of the community enterprise processing herbs from local wisdom in Ban Prue Sub-district, Krasang District, Buriram Province. The prediction for the four aspects was at 63.60% (AdjR² = 0.636).

Modes, bounds, and synthesis of optimal electromagnetic scatterers

Abstract This paper presents an optimal synthesis of material distributions in obstacles for maximal extinction, scattering, or absorption. The material synthesis is based on an explicit construction utilizing the current distribution derived from physical bounds excited from the far-field. The bounds are expressed in radiation modes for materials restricted by their resistivity and characteristic modes for materials restricted by the contrast. The results are valid for arbitrary shapes, and analytical expressions are provided for spherical shapes.

A mechanics-based data-free Problem Independent Machine Learning (PIML) model for large-scale structural analysis and design optimization

Machine learning (ML) enhanced fast structural analysis and design recently attracted considerable attention. In most related works, however, the generalization ability of the ML model and the massive cost of dataset generation are the two most criticized aspects. This work combines the advantages of the universality of the substructure method and the superior predictive ability of the operator learning architecture. Specifically, using a novel mechanics-based loss function, lightweight neural network mapping from the material distribution inside a substructure and the corresponding continuous multiscale shape function is well-trained without preparing a dataset. In this manner, a problem machine learning model (PIML) that is generally applicable for efficient linear elastic analysis and design optimization of large-scale structures with arbitrary size and various boundary conditions is proposed. Several examples validate the effectiveness of the present work on efficiency improvement and different kinds of optimization problems. This PIML model-based design and optimization framework can be extended to large-scale multiphysics problems.

Multi-objective optimization of a triple-eccentric butterfly valve considering structural safety and sealing performance

The structural safety and sealing performance of a triple-eccentric butterfly valve are crucial technical indicators that influence its reliability and service life. In this study, a new multi-objective optimization strategy is proposed to realize a lightweight design of valve trims, reduce the maximum equivalent stress, and reasonably distribute the sealing-specific pressure. A two-stage optimization scheme is designed by combining topology optimization (TO) and response surface methodology optimization (RSM). The topology optimization is employed to allocate the material distribution of the valve trims and provide the parameters for the response surface optimization, while the response surface methodology optimization conducts a further revision and optimization of the structural parameters of the valve trims. The results of the simulation experiments indicate that the maximum equivalent stress of the lightweight designed valve trims is reduced from 290.85 MPa to 99.88 MPa, and the maximum sealing-specific pressure of the sealing surface is reduced from 197.78 MPa to 77.83 MPa. Additionally, a novel approach is presented for assessing the sealing performance using the clearance of the fitting surface. This method can intuitively evaluate the state of metal sealing and guide the design of the fitting tolerance by analyzing the sensitivity of the dimensional deviation to the sealing-specific pressure. The findings demonstrate that the optimized valve exhibits good structural safety and sealing performance.

Conductive paths generation using topology optimization for worst-case thermal design in space systems

Designing thermal systems for space platforms is a challenging task due to the wide variability in thermal conditions during the orbit and the strict constraints imposed by other subsystems. Several strategies have been developed to address these challenges while minimizing the thermal control subsystem’s signature, encompassing different algorithms optimize components positions in the platform. When relocation is not possible, thermal couplings between components can be modified to enhance heat transfer and achieve more uniform temperature distribution. To design optimal thermal paths in 2D space structures, in this paper a topology optimization framework based on the Heaviside Projection Method is introduced, using the Lumped Parameter Method (LPM) and taking the radiation heat transfer into account. The algorithm’s performance is tested on a Printed Circuit Board (PCB) by designing an optimal copper layer to meet specific thermal requirements under both extreme hot and cold conditions. Results show a significant improvement in thermal compliance for all components with the addition of this high-conductivity layer. Additionally, a reduction method is introduced to transfer the material distribution from the optimization to a coarser mesh of any size, which is useful to facilitate its implementation in existing software, where a large number of degrees of freedom can be a limitation.

Histopathological Analysis of Pseudoexfoliation Material in Ocular Surgeries: Clinical Implications

Background: Pseudoexfoliation syndrome (PEX) is a common age-related ocular condition characterized by the accumulation of a fibrillar, pseudoexfoliative material on the anterior segment of the eye. This study aims to investigate the histopathological characteristics of pseudoexfoliative material within different ocular structures, including the eyelid, conjunctiva, and anterior lens capsule. Methods: A total of 32 anterior lens capsules, 3 eyelid fragments, and 12 conjunctival specimens were obtained from patients clinically diagnosed with PEX during ocular surgeries at the Onioptic Hospital of Ophthalmology. The tissue specimens were subsequently processed using the classical histological technique of paraffin embedding. This process enabled the production of serial sections with a thickness of 4 microns, facilitating the microscopic examination of fine details. The sections were stained with the hematoxylin-eosin (HE) method for the observation of microscopic structures. Results: This study’s findings reveal that PEX material, characterized by its fibrillar and amorphous components, is consistently present across multiple ocular structures, including the anterior lens capsule, eyelid, and conjunctiva. When stained with H&E, the PEX material typically appears as amorphous, eosinophilic deposits. Under higher magnification, these deposits exhibit a fibrillar structure, often appearing as irregular, granular, or filamentous aggregates. Conclusions: The deposit of fibrillar material in the eyelid and conjunctiva, though less commonly emphasized compared to other structures, is a significant finding that sheds light on the systemic nature of the syndrome. The consistent identification of fibrillar eosinophilic deposits across these structures highlights the systemic distribution of PEX material, reinforcing the notion that PEX syndrome is not confined to the anterior segment of the eye.

Shear characteristics of nonuniform distribution of granular materials in ring shear test and impact on landslides

Knowledge of the shear behavior of landslide soil is very important for understanding landslide dynamics. This study investigated the shear behavior of base soil particle materials using ring shear tests with glass beads. Samples with varying particle sizes and distributions were examined to explore how particle size affects shear behavior at different shear velocities. Analysis of the samples included assessment of shear stress, displacement-shear stress fluctuations, and changes in the shear stress standard deviation. Results showed that with increasing shear displacement, shear stress fluctuations stabilize. Rather large difference particle size differences lead to more uniform particle mixing and a lower shear stress standard deviation. Conversely, when smaller particles predominate, particle mixing is less uniform, resulting in a higher shear stress standard deviation. Additionally, this study discussed the shear dilation and compaction mechanisms of samples under large displacement shear.

Application of Computer-Aided Design Software to the Simulation and Analysis of Composite Material Properties in Housing Engineering Structures

Reinforced polymer composites are widely used in engineering applications due to their excellent mechanical properties, and this paper combines experiments and numerical simulations to fully examine the properties of the composites. The article takes the reinforced concrete structure of civil engineering as the basis for experimental testing on the basic properties of carbon fiber composites in its application. Subsequently, the intrinsic model of reinforced concrete and carbon fiber composites was constructed, and each finite element unit of the member was selected to simulate and finite element analysis the performance of the composites through ABAQUS computer-aided design software. The results show that increasing the diameter of carbon fibers will reduce the number of carbon fibers at the same time, which will reduce the toughness of the composite material, random and chaotic distribution of carbon fibers for the improvement of the compressive properties of concrete can achieve a relatively balanced effect, and the high elastic modulus carbon fibers for the improvement of uniaxial and cyclic compressive properties of concrete play a dominant role. In addition, the oriented elliptical fibers in the long-axis direction have a significant increase in the modulus of elasticity and strength of the material, and this phenomenon will become more and more obvious with the increase of the length-to-diameter ratio. The reasonable structural design may help to improve the performance of composites and enhance their adaptability for engineering applications.

A new efficient imaging reconstruction method for muon scattering tomography

Muon scattering tomography (MST) is a promising technique in nuclear security inspection, utilizing its multiple scattering property which is sensitive to elements with high atomic numbers, and is also correlated with the material density. A proper imaging reconstruction method is essential for revealing the spatial distribution of materials within an object from measurements. This work proposes a new imaging reconstruction method called “big voxel and angle capping”. The scattering angle is reconstructed using the conventional Point of Closest Approach (PoCA) method. In the new method, reconstructed scattering angles belonging to voxels in an l×m×n matrix are aggregated into the center voxel, termed the “big voxel”. This significantly reduces statistical fluctuations in each big voxel. Subsequently, the influence of large scattering angles on determining material densities in big voxels is mitigated using a capping angle. The proposed algorithm is tested on the experimental data comprising approximately 1.8×104 muon scattering events detected in ∼ 24 h. The mean square error (MSE) and the structural similarity index measure (SSIM) indices are employed to quantitatively assess the imaging quality and optimize the new method. After scanning the two major parameters, the optimal parameter space is achieved with the big voxel size of ∼ 9, and the capping angle of ∼4∘ for tungsten blocks. The imaging quality is more sensitive to the capping angle than the big voxel size. An appropriate capping angle effectively removes large artifacts in reconstructed images caused by muon events with large scattering angles. This method is efficient in terms of both time and storage consumption.

Phononic crystal-based acoustic demultiplexer design via bandgap-passband topology optimization

The wave demultiplexer, which selectively transports specific frequencies from incident waves, has garnered considerable interest for its applications across various engineering disciplines. This study introduces a new customizable design method for acoustic demultiplexers based on the topology optimization of phononic crystals (PnCs). To achieve an acoustic demultiplexer capable of filtering multiple frequencies, a topological design model for PnCs that simultaneously considers bandgaps and passbands is proposed. By assembling the optimized PnCs within the structure, the demultiplexer can separate sound waves of different frequencies into distinct output channels. In the optimization model, an objective function based on transmission rates is proposed to determine whether specific frequencies fall within the specified bandgap or passband. To solve this complex topology optimization problem, the Kriging-based material-field series expansion (KG-MFSE) approach is used to describe the material distribution and optimization of PnCs. The designed PnC unit cells can be directly integrated into the demultiplexer without requiring additional space. Based on specified combinations of passbands and bandgaps, different PnCs are designed to realize a programmable acoustic demultiplexer capable of filtering various sound waves. Numerical analyses demonstrate that the constructed acoustic demultiplexer effectively separates the specified frequencies. Finally, experimental validation of the 3D printed acoustic demultiplexer model confirms the effectiveness of the proposed optimization method.