Distribution Of Material Research Articles

Deep Learning-Based Ground-Penetrating Radar Inversion for Tree Roots in Heterogeneous Soil

Tree roots are vital for tree ecosystems; accurate root detection helps analyze the health of trees and supports the effective management of resources such as fertilizers, water and pesticides. In this paper, a deep learning-based ground-penetrating radar (GPR) inversion method is proposed to simultaneously image the spatial distribution of permittivity for subsurface tree roots and layered heterogeneous soils in real time. Additionally, a GPR simulation data set and a measured data set are built in this study, which were used to train inversion models and validate the effectiveness of GPR inversion methods.The introduced GPR inversion model is a pyramid convolutional network with vision transformer and edge inversion auxiliary task (PyViTENet), which combines pyramidal convolution and vision transformer to improve the diversity and accuracy of data feature extraction. Furthermore, by adding the task of edge inversion of the permittivity distribution of underground materials, the model focuses more on the details of heterogeneous structures. The experimental results show that, for the case of buried scatterers in layered heterogeneous soil, the PyViTENet performs better than other deep learning methods on the simulation data set. It can more accurately invert the permittivity of scatterers and the soil stratification. The most notable advantage of PyViTENet is that it can accurately capture the heterogeneous structural details of the soil within the layer since the soil around the tree roots in the real scene is layered soil and each layer of soil is also heterogeneous due to factors such as humidity, proportion of different soil particles, etc.In order to further verify the effectiveness of the proposed inversion method, this study applied the PyViTENet to GPR measured data through transfer learning for reconstructing the permittivity, shape, and position information of scatterers in the actual scene. The proposed model shows good generalization ability and accuracy, and provides a basis for non-destructive detection of underground scatterers and their surrounding medium.

A Qualitative Study of Attitudes Toward HPV Vaccine Recommendation in Otolaryngology Clinics.

The incidence of human papillomavirus (HPV)-related oropharyngeal cancers has increased such that they are now the most prevalent HPV-related cancer. In 2020, the Food and Drug Administration (FDA) expanded the indication for Gardasil-9 to include the prevention of oropharyngeal and other head and neck cancers caused by selected HPV types, but uptake remains low. Otolaryngology office interactions may provide opportunities to increase uptake, given the relevance of HPV to clinical practice. This study explored the feasibility of recommending HPV vaccination in otolaryngology clinics. Participants were recruited between February to June of 2022 from the alumni of the residency and fellowship training programs at the University of Iowa Hospitals and Clinics. Participant interviews comprised open-ended questions pertaining to otolaryngologists' attitudes toward HPV vaccination recommendation. Interview recordings were transcribed, coded, and analyzed for themes. Participants were willing to respond if patients asked about the HPV vaccine, although a common attitude toward vaccine discussions was that they were a pediatrician's responsibility. One barrier to recommending HPV vaccination was providers' concern that discussing the vaccine when not directly relevant to the patient's chief complaint could result in patient frustration. Nevertheless, participants endorsed the feasibility of discussing the vaccine during follow-up visits after the patient's needs had been addressed or via the distribution of educational materials to patients. Otolaryngologists do not currently identify recommending HPV vaccine uptake as their clinical responsibility. While such recommendations may not be feasible in every patient encounter, there could be a role for this in the appropriate clinical scenario. These findings can be used to inform interventions aimed at recommending the vaccine in otolaryngology clinics.

Environmental release behavior, cell toxicity and intracellular distribution of novel biodegradable plastic materials.

In response to the increasingly severe issue of plastic waste, biodegradable plastics have garnered extensive attention as a potential alternative to traditional plastics. Among these materials, biodegradable plastics hold a dominant position. The objective of this study was to assess the environmental risks of five commercially available biodegradable plastics: polyglycolic acid (PGA), polylactic acid (PLA), poly(butylene succinate) (PBS), poly(butylene carbonate) (PBC), and poly(butylene adipate-co-terephthalate) (PBAT). The evaluation included their physical properties, microplastic release behavior, and cytotoxicity. In addition, the effect of age process on the environmental behavior of biodegradable plastic materials was further investigated. The results revealed that PGA and PBS exhibited lower risks in terms of microplastic release, whereas PLA demonstrated higher environmental mobility. Further cytotoxicity experiments indicated that PLA and PBS exerted significant toxic effects on human cell lines, including human normal liver cells (LO2), human monocytic leukemia cells (THP-1), human umbilical vein endothelial cells (HUVECs), and human colon carcinoma cells (Caco-2). Additionally, this study utilized Nile Red labeling to observe the co-culture system of PGA with THP-1cells, uncovering that THP-1cells gradually engulfed and internalized PGA microplastics over time. This finding provides new insights into the potential mechanism by which microplastics promote cell proliferation. Moreover, we also found that the aging process partially reduced the cytotoxicity of PGA, but had little effect on environmental mobility. Considering the comprehensive research findings, PGA is considered an ideal material for large-scale applications due to its low cytotoxicity and environmental risks. In contrast, the environmental safety of other types of plastics requires more comprehensive risk assessment to determine their suitability. This study provides significant scientific evidence for the environmental impact assessment of biodegradable plastics and plays a crucial role in promoting the development of sustainable plastic alternatives.

Rationale, design and pre-randomization data for a cluster randomized trial to assess the effect of a digitally enabled quality improvement intervention on LDL-C control in established atherosclerotic cardiovascular disease patients: The SAPPHIRE-LDL Trial.

Translating evidence into clinical practice in the management of established atherosclerotic cardiovascular disease patients is challenging. Few quality improvement interventions have successfully improved patient care. The main objectives are to evaluate the impact of a digitally enabled multifaceted quality improvement (QI) intervention on the control of LDL-cholesterol (LDL-C) in atherosclerotic cardiovascular disease (ASCVD). We designed a pragmatic two-arm cluster randomized trial involving 28 clusters (outpatient clinics from public or private hospitals or private practices). Clusters are randomized to receive a digitally enabled multifaceted QI intervention or to routine practice (control). The QI intervention includes reminders, electronic clinical decision support algorithms, audit and feedback reports, and distribution of educational materials to health care providers, as well as electronic educational materials and app-based tools for drug adherence control, lipid profile control, and communication to participants. The primary endpoint is the LDL-C at 06 months after the intervention period. All analyses are performed following the intention-to-treat principle and take the cluster design into consideration by using individual-level regression modeling (generalized estimating equations-GEE). If proven effective, this low-cost, digitally enabled multifaceted QI intervention would be highly useful in promoting optimal LDL-C control in ASCVD patients. ClinicalTrials.gov NCT05622929.

Nonlinear Transient Heat Transfer and Optimisation of Multidirectional (1D/2D/3D) Functionally Graded Porous Composites

In this paper, the steady and transient heat transfer behaviours of multidirectional (1D/2D/3D) functionally graded composite plates are investigated. Also, two different porosity types, i.e., even and uneven distributions, are considered along with material gradation. Here, the spatial/temperature-dependent effective material properties of these highly heterogeneous composites with porosity are evaluated using the extended Voigt’s homogenisation scheme via multi-variable power-law functions and further verified with the representative volume element (RVE) scheme. In continuation, generalised mathematical models are developed by including material nonlinearity using the cubic-polynomial-based temperature-dependent constitutive model. The Poisson’s and Laplace’s equations are utilised for steady and transient heat transfer problems, respectively, and the weak form is derived using the Galerkin method. Further, coupled finite element method (FEM)–finite difference method (FDM) is adopted via Picard’s successive iteration and Crank–Nicolson technique to compute the nonlinear transient temperature. The proposed model is verified by comparing it with the previously reported results. In addition, the effects of heterogeneity, porosity, power-law indices and boundary conditions on the steady/transient heat transfer responses of multidirectional functionally graded plates are examined and discussed in detail. At last, the optimum material distributions are obtained using the response surface methodology (RSM) by minimising the heat transfer responses.

A Production-Logistics prediction method integrating Spatial-Temporal features in flexible production workshop for buffer allocation problem

To meet the demands of personalized manufacturing, characterized by customized production with varying batch sizes, logistics equipment such as Automated Guided Vehicles (AGVs) play a critical role in the manufacturing process. However, the distribution of multiple batches is influenced by various factors, with buffer zone capacity allocation emerging as a key challenge. Optimizing buffer zone allocation necessitates a thorough consideration of both spatial characteristics (e.g., shop floor layout and workpiece pathways) and temporal characteristics (e.g., the sequence of material distribution) to enhance resource allocation, reduce bottlenecks, and improve efficiency. This research proposes a novel logistics prediction method for flexible production plants, utilizing a graph attention network that integrates spatial–temporal features. The method first applies a multi-head attention mechanism to capture significant temporal information. Then, a graph convolutional network is employed to model the workshop layout topology and workpiece processing paths, thereby extracting the spatial features of logistics. This spatial information is sequentially processed through a gated recurrent unit and the multi-head attention mechanism to capture the dynamic temporal features of logistics. The proposed model is ultimately employed to predict production logistics in a flexible manufacturing workshop. The experimental results of the MA-T-GCN (Multi-head Attention Temporal Graph Convolution Network) model on production logistics prediction demonstrate an improvement over the best-performing baseline methods on standard benchmark metrics under varying experimental conditions.

Unraveling the Dusty Environment around RT Vir

Abstract Infrared (IR) studies of asymptotic giant branch (AGB) stars are critical to our understanding of the formation of cosmic dust. In this investigation, we explore the mid- to far-IR emission of the oxygen-rich AGB star RT Virginis. This optically thin dusty environment has unusual spectral features when compared to other stars in its class. To explore this enigmatic object we use the one-dimensional radiative transfer modeling code DUSTY. Modeled spectra are compared with observations from the Infrared Space Observatory, InfraRed Astronomical Satellite, the Herschel Space Observatory, and a host of other sources to determine the properties of RT Vir's circumstellar material. Our models suggest a set of two distant and cool dust shells at low optical depths (τ V,inner = 0.16, τ V,outer = 0.06), with inner dust temperatures T 1 = 330 K, T 3 = 94 K. Overall, these dust shells exhibit a chemical composition consistent with dust typically found around O-rich AGB stars. However, the distribution of materials differs significantly. The inner shell consists of a mixture of silicates, Al2O3, FeO, and Fe, while the outer shell primarily contains crystalline Al2O3 polymorphs. This chemical change is indicative of two distinct epochs of dust formation around RT Vir. These changes in dust composition are driven by either changes in the pressure–temperature conditions around the star or by a decrease in the C/O ratio due to hot-bottom burning.

Kinematic characteristics of elastic screen surface and screening performance of material groupsunder different additional excitation conditions

ABSTRACT Screening is indispensable process, which is extensively used in coal separation on a global scale. In traditional screening, material stratification is difficult to achieve, which leads to a poor screening effect. In this study, balls are added under the elastic screen surface to increase the screen amplitude and promote the loose stratification of materials. The screen surface motion characteristics, the changes of the material layer on the screen, the material distribution characteristics under the screen, and the screening efficiency are studied by means of vibration tests, high-speed dynamic recording, and screening tests. The experimental results show that when 2-ball additional excitation is applied, the highest screening efficiency of 79.45% is reached, the elastic screen surface can produce a large amplitude of up to 24.77 mm, the screen surface deformation is larger, the material layer is looser, material migration is faster, and the screening effect is better. The main screening area of the material is the second sections of the screening surface, and the screening efficiency of fine particles is mainly affected by the screening efficiency of complex excitation screening. With the increase of the screening surface length, the screening effect of complex excitation elastic screening becomes better.

Study of the Effect of Graphene Content on the Electrical and Mechanical Properties of Aluminium–Graphene Composites

The present paper is dedicated to the search for an alternative material based on an aluminum (Al)—few-layer graphene (FLG) composite for use in electrical applications. Due to its excellent properties, graphene has the potential for use in many applications, especially in electronics, electrical engineering, aerospace, and the automotive industry. One area where the properties of graphene can be exploited is in overhead power transmission, where the main challenge at the moment is to reduce transmission losses. The utilization of conductors that exhibit superior electrical conductivity is instrumental in ensuring the mitigation of transmission losses. The utilization of graphene or other carbon allotropes is appealing due to their elevated electrical conductivity, substantial mechanical strength, and considerable heat resistance, which can enhance the properties of the composite, thereby increasing its resistance to operational conditions, particularly long-term exposure to temperature, a parameter closely related to the current carrying capacity of the OHL. This article presents the findings of research on the production of a composite based on aluminum powder and graphene, as well as the identification of its electrical and mechanical properties. The primary challenge in this research lies in the development of a method to synthesize carbon materials with aluminum using powder metallurgy, with particular attention paid to the mixing and compacting process, which is of significant importance in ensuring the appropriate distribution of carbon material in the composite. The research carried out has determined the influence of the graphene content (0.1–1 wt.%) on the electrical conductivity (max. 35.4 MS/m) and mechanical properties of Al-FLG composites (UTS = 156 MPa).

Autonomous inverse encoding guides 4D nanoprinting for highly programmable shape morphing

Abstract Highly programmable shape morphing of 4D-printed micro/nanostructures are urgently desired for applications in robotics and intelligent systems. However, due to the lack of autonomous holistic strategies throughout the target shape input, optimal material distribution generation, and fabrication program output, 4D nanoprinting that permits arbitrary shape morphing remains a challenging task for manual design. In this study, we report an autonomous inverse encoding strategy to decipher the genetic code for material property distributions that can guide the encoded modeling toward arbitrarily pre-programmed 4D shape morphing. By tuning the laser power of each voxel at the nanoscale, the genetic code can be spatially programmed and controllable shape morphing can be realized through the inverse encoding process. Using this strategy, the 4D-printed structures can be designed and accurately shift to the target morphing of arbitrarily hand-drawn lines under stimulation. Furthermore, as a proof-of-concept, a flexible fiber micromanipulator that can approach the target region through pre-programmed shape morphing is autonomously inversely encoded according to the localized spatial environment. This strategy may contribute to the modeling and arbitrary shape morphing of micro/nanostructures fabricated via 4D nanoprinting, leading to cutting-edge applications in microfluidics, micro-robotics, minimally invasive robotic surgery, and tissue engineering.

Silver Microdisc Array Electrode Chip for Urea Detection in Saliva Samples from Patients with Chronic Nephritis.

Urea is an important biomarker for diagnosing various kidney and liver disorders. However, many existing methods rely on invasive blood sampling, which can potentially harm patients. Saliva has been recently recognized as a noninvasive and easily collectible alternative to blood for urea quantification. Electrochemical urea detection in saliva remains limited, with catalytic materials typically applied to the electrode surface via drop casting. This results in a random distribution of materials and potential aggregation on the electrode, which inevitably hinders the efficient mass transport of analytes, reducing both detection sensitivity and the utilization of catalytic materials. In this work, a silver nanoparticle (AgNP)-integrated microdisc array electrode chip was fabricated through the in situ growth of AgNPs on polydopamine (PDA) arrays, which were patterned using the microcontact printing (μCP) technique on an indium tin oxide (ITO) glassy substrate. The resulting AgNP microdisc array chip sensor exhibited much higher sensitivity toward urea sensing and greater material utilization as compared to traditional drop-cast electrodes, due to the enhanced mass transfer. Furthermore, the chip sensors demonstrated superior selectivity when challenged with potential interferences. More importantly, reliable urea quantification was achieved in clinical saliva samples from nephritis patients. These results indicate that the current sensor presents great opportunities for developing a noninvasive and sensitive liquid biopsy platform for urea determination in clinical diagnosis applications.

Multipatch IGA for stress-constrained minimum weight structural topology optimization

In this article, an isogeometric analysis (IGA) formulation with various patches (multipatch approach) is proposed to solve the structural topology optimization (STO) problem. The multipatch formulation enables the solution of STO problems with geometries not equivalent to rectangles by using IGA. For this purpose, a minimum weight with stress constraints (MWSC) problem is stated. A quadratic B-splines basis defined for each patch is used to model the material distribution. The structural analysis is computed with IGA. The introduction of all of the stress constraints in the formulation of the problem is made with an overweight constraint (OC). Finally, the multipatch approach is validated with the solution of some benchmark problems.

Unraveling Redox Mediator-Assisted Chemical Relithiation Mechanism for Direct Recycling of Spent Ni-Rich Layered Cathode Materials.

The increasing demand for Li-ion batteries across various energy storage applications underscores the urgent need for environmentally friendly and efficient direct recycling strategies to address the issue of substantial cathode waste. Diverse reducing agents for Li supplements, such as quinone molecules, have been considered to homogenize the Li distribution in the cathode materials obtained after cycling; however, the detailed reaction mechanism is still unknown. Herein, the ideal electrochemical potential factor and reaction mechanism of the redox mediator 3,5-di-tert-butyl-o-benzoquinone (DTBQ) for the chemical relithiation of high-Ni-layered cathodes are elucidated. Here, 100% efficiency of DTBQ-assisted chemical relithiation is achieved by adjusting the direct immersion time of Li-deficient cathode electrodes. The reversible reaction features of the physical and chemical structures of both the regenerated cathodes and the DTBQ molecules are investigated using advanced characterization and density functional theory calculations. These findings emphasize the potential of redox-mediator-assisted chemical relithiation for realizing direct recycling processes and offer a facile and sustainable solution for battery recycling.

Research on Robot Membrane Material Selection and Distribution Route Optimization on College Campuses

An e-commerce logistics park, as a hub for e-commerce logistics, possesses the traits of high task volume and intensive package delivery. It is inefficient and dangerous to rely solely on manual work. Thus, there is some practical significance and benefit in figuring out how to implement cutting-edge delivery techniques to boost the delivery effectiveness of e-commerce logistics parks. This study combined the features of the e-commerce logistics and distribution environment, identified and eliminated the three robot types that are currently suitable for intelligent distribution, built an evaluation index system to assess the robot model selection scheme appropriate for e-commerce logistics and distribution. To assess the robot model selection strategy, we built an entropy weight-material element expansion model and computed the weighted correlation degree and proximity to various grades of the three robot kinds and five assessment grades, as well as the degree of proximity with various grades, determined the distribution robot model. Following example verification, the research presented in this paper can successfully conduct a reasonable and scientific evaluation of the distribution robot selection and can offer specific references for the more thorough decision-making process of robot selection for logistics and distribution in e-commerce parks.

Optimized Collaborative Scheduling of Unmanned Aerial Vehicles for Emergency Material Distribution in Flood Disaster Management

Optimized Collaborative Scheduling of Unmanned Aerial Vehicles for Emergency Material Distribution in Flood Disaster Management

The influence of the carbon nanofiller in the PDMS-based composites on the strain resistive effect

In this study flexible polymer nanocomposite material with different types of carbon nanotubes (CNTs) (single-walled CNT [SWCNT] or multi-walled CNT [MWCNT]) has been obtained for use in stretchable elements of flexible structures. The features of electrically conductive nanostructures and their distribution in the nanocomposite material have been studied using Raman spectrometer and scanning electron microscope, respectively. Setup for studying the functional characteristics of the nanocomposite material based on a testing machine has been developed. The setup ensures simultaneous measurement of the electrical resistance of the nanocomposite material under cyclic tension. The ultimate tensile strength of the polymer composite under 25% tension with different electrically conductive nanostructures has been determined. It has been exposed for a sample with MWCNT, the ultimate tensile strength is significantly lower. It has been revealed that the highest tensile strength had been achieved in composites at about 0.37 MPa. The strain sensitivity (gauge factor [GF]) of polydimethylsiloxane (PDMS)/MWCNT has higher GF value compared to PDMS/SWCNT. This shows a higher potential for using them as fillers for creating sensor systems based on nanocomposite conductive materials.

Neuron-inspired CsPbBr3/PDMS nanospheres for multi-dimensional sensing and interactive displays

Multifunctional materials have attracted tremendous attention in intelligent and interactive devices. However, achieving multi-dimensional sensing capabilities with the same perovskite quantum dot (PQD) material is still in its infancy, with some considering it currently challenging and even unattainable. Drawing inspiration from neurons, a novel multifunctional CsPbBr3/PDMS nanosphere is devised to sense humidity, temperature, and pressure simultaneously with unique interactive responses. The carefully engineered polydimethylsiloxane (PDMS) shell enables the reversible activity of the core CsPbBr3, serving a dual role similar to dendrites in conveying and evaluating external stimuli with high sensitivity. Molecular dynamics analysis reveals that the PDMS shell with proper pore density enhances the conductivity in water and heat, imparting CsPbBr3 with sensitive but reversible properties. By tailoring the crosslinking density of the PDMS shell, nanospheres can surprisingly show customized sensitivity and reversible responses to different level of stimuli, achieving over 95% accuracy in multi-dimensional and wide-range sensing. The regular pressure-sensitive property, discovered for the first time, is attributed to the regular morphology of the nanosphere, the inherent low rigidity of the PDMS shell, and the uniform distribution of the CsPbBr3 core material in combination. This study breaks away from conventional design paradigms of perovskite core-shell materials by customizing the cross-linked density of the shell material. The reversible response mechanism of nanospheres with gradient shell density is deeply explored in response to environmental stimuli, which offers fresh insights into multi-dimensional sensing and interactive display applications.

Educational intervention to increase childhood immunization uptake in rural Pakistan

Background: Childhood immunization uptake in rural Pakistan is low, due mostly to myths and misunderstanding regarding its importance. Aim: To determine the effect of an educational intervention on childhood immunization uptake for infants aged ≤ 16 weeks in 5 rural districts of Sindh Province, Pakistan. Methods: This quasi-experimental study was conducted from September 2023 to January 2024 among parents of 1200 children aged 3–5 weeks enrolled in intervention and control villages. Education campaigns that included face-to-face sessions and distribution of print and video information materials were conducted with families of children in the intervention group. Multivariable Cox regression was used to assess the effect of the intervention on immunization uptake. Results: After the initial immunization at birth, 19.8% of infants in the intervention villages and 24.8% in the control villages had not completed their Expanded Programme on Immunization vaccinations at age 16 weeks. Children in the intervention villages were significantly more likely to have been completely vaccinated at 14 weeks. Age, gender, household monthly income, place of birth, maternal education, and distance from immunization facility were not significantly associated with uptake. Conclusion: Educational interventions, including use of social media, can help increase childhood immunization uptake in rural areas of developing countries like Pakistan.

A wideband coaxial-to-waveguide transition devised with topology optimization

Topology optimization is a powerful technique that utilizes the distribution of material properties along with surface topology as parameters to expand a specified performance. While primarily used as a foundational step in regenerative design for structural mechanics, the general TO framework is also applicable to many of the complex issues in electromagnetics such as frequency agile mode converters. This is considered a difficult parameter to optimize since RF components operate on resonance. TO is used on the coaxial-to-rectangular waveguide converter in the range X band. The radiative element chosen is a patch antenna with a ground stop. The original design is transformed into a binary material distribution matrix, where each cell is assigned a value of 0 or 1, while ensuring connectivity between the cells. Then the cell values are altered via a BPSO algorithm to optimize the width of the operating band, resulting in a complex structure that yields a bandwidth 38% larger than the control. The optimized patch structure is fabricated and its performance verified in the frequency range 8-12 GHz.

Interface characterization of additively manufactured Inconel 718 heterogeneous products: Microstructural and surface characteristics

Abstract The present work analyses the effect of laser powder bed fusion (LPBF) remanufacturing of wrought Inconel 718 on the metallurgical and surface characteristics of the part. The remanufactured part experienced geometrical mismatch due to computer-aided design (CAD) misalignment with the substrate. As a result, a ~200 μm shift in a material deposition is observed, leading to a material deposition without support from the substrate on one edge. The microstructural analysis of the remanufactured part showed an interface between the wrought substrate and LPBF processed layers. The substrate showed an equiaxed grain structure. However, a strongly textured columnar grain structure was observed in the remanufactured region. The remanufactured Inconel 718 showed lower micro-hardness, inhibiting the precipitation of strengthening precipitates during the LPBF process. The surface characterization showed a higher surface roughness and anisotropy in material distribution for overhanging edges due to layer deformation and lack of support from the substrate. It was observed that due to geometry mismatch, the overhanging side experienced layer deformation, thus leading to the formation of large undulations on the surface. A higher area fraction of fused powder particles on the overhanging side shows ineffective heat transfer due to the region's lack of efficient support.