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This paper proposes a family of multi-stable metastructures with multiple layers, which possess the capability of multi-degree of freedom deformations. In its single layer, four preshaped beams connecting two frames are employed as the main component for the design of multi-stable metastructures. Compared with the traditional flat state obtained by axial compression when all beams snap through, four inclined stable states are easy to trigger by lateral compression at a local position when two adjacent beams snap through. The transitions between these states are studied by both experiments and numerical simulation. The transition to inclined states requires less energy than the transition to the flat state. Different trends of load–displacement responses are associated with loading positions and transitions. A parametric analysis is performed to illustrate the relationship between the stability of inclined states and critical parameters, such as span, apex height, and thickness. Two types of hourglass double-layer units are designed and studied through experiments. The continuous transitions in two steps or three steps are observed, and the load–displacement response is the accumulation of responses from each single layer. At last, two multi-layer structures with multi-stability have been developed to demonstrate their deformation capability in multiple directions through multiple steps.

Ultrasonic welding is a fast and efficient solid-state welding process widely used in various industries. This study focuses on optimizing seam quality and peel strength in multi-layered hybrid textile materials using continuous ultrasonic welding. The influence of welding process parameters (pressure force, power, and speed) on multi-layered peel strength is examined. Three-by-three experimental designs for two and three-layer weld seams with 6 and 12 mm welding widths were developed and applied using superimposed seam type. The impact of varied factors on multi-layered peel strength was analyzed statistically and explored their corresponding tendencies in the relationships. Numerical optimization and analytical models were used to determine parametric levels for achieving desired peel strength. The results show that peel strength is affected by welding parameters, with variations observed based on layer, width, and speed. Increasing speed reduces peel strength, while higher power and pressure force enhance peel strength up to a certain point. However, excessive power and pressure forces can cause material deformation and reduce peel strength. The study also found a strong correlation between power and peel strength, emphasizing the importance of energy input during welding. Power and speed are identified as significant determinants of peel strength, with their combined influence playing a crucial role. The optimal peel strength (34.86 N/12 mm) is achieved at a welding speed of 2.11 m/min, power of 118.18 W, and pressure force of 343.94 N for a three-layer weld seam with a 12 mm welding width. Nonlinear quadratic analytical models are developed to predict multi-layered peel strength, and their results align closely with the actual points. Overall, this research provides valuable insights into optimizing seam quality and peel strength for multi-layered hybrid textile materials, benefiting weather protection applications and advancing bonding techniques in ultrasonic welding.

Background: Breast cancer (BC) has been identified as a significant contributor to the rising number of female cancer deaths. As, it has become clear that breast cancer development depends on the interplay of several biological factors against a single molecule. This research aimed to use proteomics to gain a regulatory and metabolic understanding of BC pathophysiology. Method: For the study, a breast cancer proteomics dataset was downloaded from ProteomeXchange and then analyzed by employing MaxQuant and Perseus. Functional enrichment analysis through Metascape and Cytoscape software showed DEPs related biomedical phenomena with potential abruption. The expression of selected lncRNA in terms of the highest connectivity parameters was then quantitatively assessed through RT-PCR in 30 tumor tissues of breast cancer patients, as compared to the adjacent healthy ones. Result: The results indicated that among the 3048 identified proteins, 1149 were differentially expressed, which could be mainly enriched in several key terms. Furthermore, the obtained findings revealed that ITGB1-DT was significantly overexpressed in tumor tissues. Moreover, we found five potential compounds that could be attributed to ITGB1-DT targets (ATN-161, Firategrast, SB-683698, dabigatran-etexilate, and tranexamic-acid). Conclusion: These analyses proposed that ITGB1-DT could be employed as a differentiated factor to identify breast tumor tissues in healthy samples. Besides this, Firategrast could be introduced as a potential remedial agent for breast cancer patients. Overall, from the analysis of a proteomics dataset, an integrative map was generated, and a novel biomarker that may have been implicated in the early detection of BC was introduced.

There are some difficulties in solving the theory of stress wave propagation in multi-layer media. To solve the problem of stress wave propagation in multi-layer media under the impact load, this paper theoretically makes further derivation and discussion based on viscoelastic analogy method. To further verify the feasibility of the theoretical solution, LS-DYNA is used to simulate the three-layer medium. The simulation results show that comparing the peak stress obtained from the numerical inversion of the Laplace function after the Laplace transform with the simulation results, the maximum error of the peak stress is about 9.5%, and the minimum error is about 1.7%. The results show that the theoretical solution agree with the simulation results, and the theoretical solution has specific feasibility. The theoretical solution method deduced in this paper further develops the viscoelastic analogy method, which has a specific reference value for the rapid calculation of the stress wave propagation law in multi-layer media.

In this work, multi-layer PECVD SiNx/SiNx and SiNx/SiOy passivations are developed featuring very high soft breakdown strength and tunable stress properties, which would allow for stress engineering and wafer bow minimization. AlGaN/GaN-on-Si wafers (150 mm) with very low initial bow (

Although the phytotoxicity of graphene-based materials has been investigated extensively, the effects of different graphene-based materials on nutrient uptake in plants remain unclear. Here, we analyzed the differences in phytotoxicity between single-layer graphene oxide (sGO) and multi-layer graphene oxide (mGO) by analyzing the growth status and nitrate (NO3–) accumulation in wheat plants at 0, 100, 200, 400, and 800 mg L−1 graphene oxide supply. Both sGO and mGO displayed concentration-dependent inhibitory effects on biomass, root length, number of lateral roots, and nitrogen (N) nutrient status. Treatment with 400 mg L−1 sGO caused 0.9-, 1.3-, and 1-fold higher reductions in NO3–-N, assimilated N, and total N concentrations in roots, respectively, than mGO treatment. Analysis of root oxidative stress and in situ NO3– uptake revealed that sGO caused more significant damage to the root tip and a lower NO3– net influx rate than mGO. In addition, the expression of NO3– transporter (NRT) genes in roots, including NRT1.5, NRT2.1, NRT2.2, NRT2.3, and NRT2.4, under sGO treatment were lower than those under mGO treatment. Overall, sGO treatment induced a more severe inhibitory effect on root growth and NO3– uptake and accumulation than mGO treatment, accompanied by significant suppression of the expression of NRTs in sGO-treated roots. This study provides a physiological and molecular basis for studying the phytotoxic effects of various sizes of graphene oxide.

This paper is a case study on a thermal protection system in a combustion chamber of a ramjet. A multilayer passive thermal protection system (MPTPS) with carbon-phenolic material was established, and the temperature distribution and insulation performance of MPTPS were studied. The problem is that the carbon-phenolic material is pyrolyzed when subjected to high temperatures, leading to the changes in its thermal properties (e.g., density, specific heat capacity, and thermal conductivity.). Moreover, the carbon-phenolic material absorbs heat during the pyrolysis procedure of phenolic resin. Therefore, in this paper, several experimental studies were conducted on carbon-phenolic composites to investigate its pyrolysis characteristics, including tube furnace heating experiment and Py-GC-MS experiment. On the other hand, a one-dimensional multilayer transient heat conduction approach was developed, many calculations were numerically performed to study the effects of negative heat sources and the thickness of carbon-phenolic composites on the thermal insulation performance of MPTPS. As a result, the carbon-phenolic material was pyrolyzed from 200 °C, and the mass-loss rate was 25% when the heating temperature increased up to 900 °C; the negative heat source delayed the temperature rising point and decreased the outer wall temperature; the thickness of the carbon-phenolic composites affected the final outer wall mainly by conduction.

In this investigation, multi-layer copper sheets are fabricated using accumulative roll bonding (ARB). Evolution of microstructure and dislocation density during ARB and after that during annealing treatment at 500 °C are investigated. In addition, the evolution of voids at the interfaces between stacking layers which may cause delamination and premature fracture are statistically analyzed. It is found that the grain structure, dislocation density, size and volume fraction of voids can affect tensile properties and electrical resistivity. The average grain size in annealed multilayered copper sheets depends on the imposed strain during deformation, but as well, the thickness of the stacking layers which can control grain growth. A fraction of the interface is left out with no solid metallurgical bonding and form voids. The average void size reduces with further deformation. However, the surface fraction and number density of the voids increase which is due to the greater number of interfaces in line with larger number of stacking layers. With 2 cycles of ARB, the ultimate tensile strength of the samples increases significantly and the ductility reduces. However, with further deformation, ductility improves due to the reduction in dislocation density. After annealing, the ductility exceeds its initial values which is attributed to swarm necking resistance of many stacking layers in the multi-layer product. The specific electrical resistivity (SER) of the annealed multi-layer sheets would not equal the initially annealed sample which is due to the finer grain structure and the interfaces between stacking layers.

With the explosive development of many emerging fields, such as wearable devices, electronic skins, and flexible batteries, it urgently needs advanced polymer films with precisely controlled physical and chemical properties. Microfluidic technology that can be used to generate controllable laminar flow in the microchannels provides new opportunity for one-step fabricating such kind of polymer films. In this review, we summarize the development of advanced polymer films with accurately controlled thickness in micro/nanometer, and heterogeneous structures and compositions, taking advantage of the unique microfluidic laminar flow. We first briefly introduce the unique characteristics of microfluidic laminar flow, and the materials and related fabrication methods of microfluidic devices. Then, emphasis is placed on the preparation strategies of advanced polymer films based on microfluidic laminar flow. Finally, we put forward personal views on future trends of this promising technology and aim to promote the development of advanced polymer films by using the microfluidic laminar flow and potential applications in various fields.

The terahertz frequency band becomes a growth platform of various applications from medical imaging to indoor communications. Emerging new materials such as graphene and developing reliable models paved the design way for graphene-based microstructures. This paper proposes a relatively comprehensive design methodology for graphene-based multi-layers structures. The procedure includes forming device geometry, finding graphene patterns, material types, and optimizing control parameters. In this way, a reconfigurable THz wave absorber is introduced. Exploiting a multi bias scheme for a single graphene layer provide opportunity to affect device reaction via bias itself and patterns period simultaneously which increase adjustability of device response. Also using two different graphene patterns turns the device complex regarding design optimizations and simulations. So a well-known and simple circuit representation is used to design the proposed methodology and the proposed device. Knowing equivalent circuit models for the device elements triggers developing an evolutionary algorithm to search for a desirable response. In this context, the paper suggests using a weighted binary matrix in the design process. The matrix determines bias schemes for each layer. Then an evolutionary algorithm optimizes whole biases values. The expectation is more in-depth control over the device behavior via biases values. This is verified by exploited circuit model formulations and Finite Element Method (FEM) as numerical simulation for a unique three layers device.

In order to understand the fracture resistance of nanocrystalline thin films, it is necessary to assess nanoscopic multiaxial stress fields accompanying crack growth during irreversible deformation. Here, a clamped cantilever with dimensions of 200 × 23.7 × 40 μm3 was machined by focused ion beam milling from a thin film composed of four alternating CrN and Cr layers. The cantilever was loaded to 460 mN in two steps and multiaxial strain distributions were determined by in situ cross-sectional X-ray nanodiffraction. Characterization in as-deposited state revealed the depth variation of fibre texture and residual stress across the layers. The in situ experiment indicated a strong influence of the residual stresses on the cross-sectional stress fields evolution and crack arrest capability at the CrN-Cr interface. In detail, an effective negative stress intensity of −5.9 ± 0.4 MPa m½ arose as a consequence of the residual stress state. Crack growth in the notched Cr layer occurred at a critical stress intensity of 2.8 ± 0.5 MPa m½. The results were complemented by two-dimensional numerical simulation to gain further insight into the elastic-plastic deformation evolution. The quantitative experimental and modelling results elucidate the stepwise nature of fracture advancement across the alternating brittle and ductile layers and their interfaces.

We present a design method for calculating and optimizing sound absorption coefficient of multi-layered porous fibrous metals (PFM) in the low frequency range. PFM is simplified as an equivalent idealized sheet with all metallic fibers aligned in one direction and distributed in periodic hexagonal patterns. We use a phenomenological model in the literature to investigate the effects of pore geometrical parameters (fiber diameter and gap) on sound absorption performance. The sound absorption coefficient of multi-layered PFMs is calculated using impedance translation theorem. To demonstrate the validity of the present model, we compare the predicted results with the experimental data. With the average sound absorption (low frequency range) as the objective function and the fiber gaps as the design variables, an optimization method for multi-layered fibrous metals is proposed. A new fibrous layout with given porosity of multi-layered fibrous metals is suggested to achieve optimal low frequency sound absorption. The sound absorption coefficient of the optimal multi-layered fibrous metal is higher than the single-layered fibrous metal, and a significant effect of the fibrous material on sound absorption is found due to the surface porosity of the multi-layered fibrous.

Although the phytotoxicity of graphene-based materials has been investigated extensively, the effects of different graphene-based materials on nutrient uptake in plants remain unclear. Here, we analyzed the differences in phytotoxicity between single-layer graphene oxide (sGO) and multi-layer graphene oxide (mGO) by analyzing the growth status and nitrate (NO 3 - ) accumulation in wheat plants at 0, 100, 200, 400, and 800 mg L -1 graphene oxide supply. Both sGO and mGO displayed concentration-dependent inhibitory effects on biomass, root length, number of lateral roots, and nitrogen (N) nutrient status. Treatment with 400 mg L -1 sGO caused 0.9-, 1.3-, and 1-fold higher reductions in NO 3 - -N, assimilated N, and total N concentrations in roots, respectively, than mGO treatment. Analysis of root oxidative stress and in situ NO 3 - uptake revealed that sGO caused more significant damage to the root tip and a lower NO 3 - net influx rate than mGO. In addition, the expression of NO 3 - transporter (NRT) genes in roots, including NRT1.5, NRT2.1, NRT2.2, NRT2.3, and NRT2.4, under sGO treatment were lower than those under mGO treatment. Overall, sGO treatment induced a more severe inhibitory effect on root growth and NO 3 - uptake and accumulation than mGO treatment, accompanied by significant suppression of the expression of NRTs in sGO-treated roots. This study provides a physiological and molecular basis for studying the phytotoxic effects of various sizes of graphene oxide., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2022 The Authors. Published by Elsevier Inc. All rights reserved.)

Calcium sulfate (CS) possesses many of the requirements for an ideal bone graft material: it is biodegradable, biocompatible, and osteoconductive. However, its relatively low strength and brittleness are major obstacles to its use as a structural bone implant. Although the strength of CS can be improved by reducing porosity, its brittleness remains a major obstacle towards its use as bone graft. Here we combine two powerful toughening strategies which are found in advanced ceramics and in natural bone: Multi-layered architectures and ductile reinforcements. We first used stress analysis and micromechanics to generate design guidelines that ensure the proper failure sequence and maximize properties. We then fabricated and tested fully dense CS by hydrostatic compression layered with layers of titanium woven mesh. Flexural experiments in hydrated conditions confirmed that the ductility and strength of titanium and the adhesion at the titanium-CS interfaces (controlled by the size of the Ti mesh) are critical factors in the mechanical performance of the composite. Our best design exhibited a toughness 180 times larger than that of plain CS, together with a 46% increase in strength., (Copyright © 2021. Published by Elsevier Ltd.)

Biodegradable polymer based 'controlled release packaging' technology has ability to release packaging actives in controlled manner to prolong the food shelf-life. Currently available systems are not sufficiently capable of releasing multiple actives in sustainable fashion. Hence, the purpose of this study was to develop dual actives (antioxidant and antibacterial) loaded multilayered microparticles in one step and to release them at rates suitable for long-term inhibition of bacterial growth as well as lipid oxidation in food. In order to achieve this goal, 2 kinds of multilayered polymer particles made up of PLLA (Poly(l-lactic acid)) and PLGA (Poly(dl-lactic-co-glycolic acid) with varying viscosity were developed using emulsion solvent evaporation method. Surprisingly, low viscous PLGA resulted tri-layered particles (PLGA/PLLA/PLGA: shell/middle/core) instead of bi-layered (PLGA/PLLA: shell/core) particles as observed for high viscous PLGA. The mechanism of formation of tri-layered particles was investigated in detail. The outermost layer consisted of relatively more hydrophilic polymer PLGA along with benzoic acid (antibacterial) and the inner core comprised of hydrophobic polymer PLLA and tocopherol (antioxidant). Release study demonstrated that release rate of dual actives were significantly accelerated from tri-layered particles in comparison to bi-layered one and their release profiles can be well explained with the help of Ridger-Peppas model. Both sets of particles exhibited long-term antibacterial (against both Escherichia coli and Staphylococcus aureus) as well as antioxidant effect over a period of 60 days. The results show for the first time the feasibility of using multilayered microparticles to prolong the food shelf-life by simultaneous release of multiple actives., (Copyright © 2018 Elsevier B.V. All rights reserved.)

This work demonstrates a mass spectrometry technique to improve data reliability when analyzing degree of polymerization (DP) of high-mass polysialic acids (PSAs). Matrix-assisted laser-desorption/ionization (MALDI) time-of-flight mass spectrometry is the technique of choice for analyzing large molecules due to its wide mass working range; however, the observed DP of PSAs using such an instrument is unreliable owing to sensitivity bias towards low-mass ions. A multi-layer MALDI sample preparation protocol is demonstrated in the current study to improve PSA sensitivity, and a dynamic instrument optimization method (DIOM) is employed to minimize detector saturation over a wide mass range. The DP information obtained in the DIOM combines a series of mass spectral data obtained with individually optimized instrument parameters to minimize the problem of sensitivity bias in respective mass ranges. The resultant mass spectra facilitate unambiguous determination of DP in the high-mass range due to significantly improved spectral quality. The main instrument parameters involved in the optimization process include extraction delay in MALDI ion source as well as the cutoff mass of the ion detector. In comparison to conventional methods, the DIOM doubles the maximum DP that can be unambiguously identified by mass spectrometry., (Copyright © 2018 Elsevier Ltd. All rights reserved.)

Accuracy plays a vital role in the medical field as it concerns with the life of an individual. Extensive research has been conducted on disease classification and prediction using machine learning techniques. However, there is no agreement on which classifier produces the best results. A specific classifier may be better than others for a specific dataset, but another classifier could perform better for some other dataset. Ensemble of classifiers has been proved to be an effective way to improve classification accuracy. In this research we present an ensemble framework with multi-layer classification using enhanced bagging and optimized weighting. The proposed model called "HM-BagMoov" overcomes the limitations of conventional performance bottlenecks by utilizing an ensemble of seven heterogeneous classifiers. The framework is evaluated on five different heart disease datasets, four breast cancer datasets, two diabetes datasets, two liver disease datasets and one hepatitis dataset obtained from public repositories. The analysis of the results show that ensemble framework achieved the highest accuracy, sensitivity and F-Measure when compared with individual classifiers for all the diseases. In addition to this, the ensemble framework also achieved the highest accuracy when compared with the state of the art techniques. An application named "IntelliHealth" is also developed based on proposed model that may be used by hospitals/doctors for diagnostic advice., (Copyright © 2015 Elsevier Inc. All rights reserved.)

Background: Padding bandage is an essential component of the multi-layer compression system used for chronic venous management. Padding plays a critical role in managing pressure over bony prominences and ensuring uniform pressure distribution around the limb circumference. Moreover, it helps in the management of heat, moisture and body fluids or exudates during the course of treatment to provide comfort to the patients., Objective: To study the effect of structural and constructional parameters on the compressional (pressure absorption or distribution) and comfort (air, moisture and heat transmission) characteristics of the padding., Methods: This research focuses on the examination of polypropylene based nonwoven padding samples. Critical factors, i.e., fiber linear density, needling density and mass per unit area, have been chosen for this study to find their significance on the performance of padding. Simple laboratory based methods have been proposed to examine pressure reduction and comfort characteristics of the padding., Results: Pressure absorption by the padding decreases with increase in mass per unit area and needling density of the padding. A padding composed of thicker fiber absorbs more pressure compared to padding made from thinner fiber. On examining comfort, it was found that the air and moisture vapor transmission increase with decrease in mass per unit area and needling density but have opposite effects with fiber linear density (p<0.01). The heat transmission decreases with increase in both mass per unit area and fiber linear density but has opposite effect for needling density., Conclusion: Padding composed of thick fiber with low mass per unit area and needling density could be more effective in pressure management and ensuring comfort. These results could be very useful for health practitioners, fabric engineers and manufactures to understand the significance of fibrous materials and their role in compression management, and could be further used as design consideration to optimized padding performance., (Copyright © 2015 Elsevier B.V. All rights reserved.)