Component Layers Research Articles

Degradable Carrageenan as a Substrate and Resistive Material for Flexible Applications.

In recent years, due to the environmental impact caused by electronic waste, decomposable components have become one of the most important topics in the world. In this study, the carrageenan material extracted from red algae was used as the resistance-switching layer of electronic components, and potassium was added to the carrageenan as a substrate (CK). CK has the advantages of excellent mechanical properties, transparency, and decomposability. In addition, the In/carrageenan/Ag/CK (ICACK) device exhibits good memory properties with a high ON/OFF ratio exceeding 107 and a retention time exceeding 104 s. Due to the doping of potassium ions, the ICACK element has a fairly good bending performance. Although bending or stretching under a small radius of curvature will not have a great impact on the electrical performance, it shows that in the future wearable or good potential in the field of implantable devices.

Strategy Based on Michael Addition Reaction for the Development of Bioinspired Multilayered and Multiphasic 3D Constructs.

The high incidence of osteochondral defects has increased the interest in the development of improved repairing alternatives, with tissue engineering being considered a promising approach. The hierarchical, complex structure of osteochondral tissue requires the design of a biomimetic multilayered scaffold. Here, a multilayered and multiphasic 3D macroporous structure was achieved at subzero temperature by the Michael addition reaction of amino functionalities of collagen with acryloyl groups of a bifunctionalized poly(ε-caprolactone). This green approach has been successfully applied to crosslink layers of different composition, both for their efficient sequential formation and connection. Polyethylenimine functionalized nano-hydroxyapatite (nHApLPEI) was added to the bottom layer. The resulting hybrid cryogels were characterized by morphology, equilibrium swelling ratios, compressive strength analysis, and MTS assay. They presented good stability, integrity, and biocompatibility. The results revealed that the properties of the prepared constructs may be tuned by varying the composition, number, and thickness of the layers. The Young modulus values were between 3.5 ± 0.02 and 10.5 ± 0.6 kPa for the component layers, while for the multilayered structures they were more than 7.3 ± 0.2 kPa. The equilibrium swelling ratio varied between 4.6 and 14.2, with a value of ~10.5 for the trilayered structure, correlated with the mean pore sizes (74-230 µm).

Physical and mechanical characterization of microwave and ultrasound-modified zein-corn starch edible films

Edible films and coatings are the biodegradable layers of edible components that are used to coat the food surface or wrap the food in the form of film. In this paper, microwave, and ultrasound technologies, at different processing conditions, separately (US, 70M, 30M) or consecutively in different order (US-70M, 70M-US, US-30M, 30M-US) were applied to the film-forming solutions based on zein and corn starch to increase the compatibility between the biopolymers and to improve some of the edible film characteristics. The physical and mechanical properties and the FTIR spectra of the films were determined. The microwave followed by ultrasound treated edible films (70M-US, 30M-US) were found to be smoother and more homogeneous than the other films. Although all films were found to have hydrophilic character, application of microwave and ultrasound technologies together increased the water contact angle values of the films, providing more hydrophobic film surfaces. 70M-US and 30M-US edible films were found to have the highest tensile strength and elongation % values, respectively. The obvious deeper peaks were observed in the amide-III band of FTIR spectra for microwave followed by ultrasound treated films as an indicator of the enhanced compatibility between zein and corn starch in the film matrix.

Utilizing time domain electrical methods to monitor MLCCs' degradation

The continued development of BaTiO3-based multilayer ceramic capacitors has contributed to further miniaturization by reducing the thickness of each dielectric layer for different voltage range components. MLCC designs that achieve higher volumetric capacitive efficiency must be balanced with stable properties over long operational times at higher fields and temperatures, raising concerns about their reliability. To improve the reliability and slow transient mechanisms of oxygen vacancy electromigration that drive the degradation of insulation resistance of MLCCs, we need to develop new models and improved metrologies to enhance the performance of MLCCs. This paper demonstrates how electrical characterization techniques, such as thermally stimulated depolarization current and highly accelerated life test, can be used to better understand MLCCs' degradation and assess their reliability. Also, the limitations of existing lifetime prediction models and their shortcomings of using mean time to failure in predicting the lifetime of MLCCs are discussed along with future perspectives on evaluating the reliability of MLCCs.

Characterisation of the Surface Free Energy of the Recycled Cellulose Layer that Comprises the Middle Component of Corrugated Paperboards

The objective of this study was to determine the polar and dispersive surface free-energy (SFE) components of the central layer of corrugated paperboards, which are made of recycled fibres. The polar and dispersive components of, and the total, SFE (also known as interfacial energy) were calculated from the contact angles of water and diiodomethane liquids on recycled cellulose sheets. The total SFE of the middle component layers of two different grammages which comprised recycled fibres ranged from 47.9 mN/m to 51.05 mN/m. The contribution of the polar component to the total surface free energy of the two types of sheets ranged from 8.6 mN/m to 12.6 mN/m. This polar contribution was significantly lower than that of water. The contact angle method proved to be a consistent way to estimate the surface properties of industrially made recycled paper products.

Novel 3D Flipwell system that models gut mucosal microenvironment for studying interactions between gut microbiota, epithelia and immunity

Gut mucosa consists of stratified layers of microbes, semi-permeable mucus, epithelium and stroma abundant in immune cells. Although tightly regulated, interactions between gut commensals and immune cells play indispensable roles in homeostasis and cancer pathogenesis in the body. Thus, there is a critical need to develop a robust model for the gut mucosal microenvironment. Here, we report our novel co-culture utilizing 3D Flipwell system for establishing the stratified layers of discrete mucosal components. This method allows for analyzing synchronous effects of test stimuli on gut bacteria, mucus, epithelium and immune cells, as well as their crosstalks. In the present report, we tested the immuno-stimulatory effects of sepiapterin (SEP, the precursor of the cofactor of nitric oxide synthase (NOS)—BH4) on the gut mucosal community. We previously reported that SEP effectively reprogrammed tumor-associated macrophages and inhibited breast tumor cell growth. In our co-cultures, SEP largely promoted mucus integrity, bacterial binding, and M1-like polarization of macrophages. Conversely, these phenomena were absent in control-treated cultures. Our results demonstrate that this novel co-culture may serve as a robust in vitro system to recapitulate the effects of pharmacological agents on the gut mucosal microenvironment, and could potentially be expanded to test the effects outside the gut.

Research on multiple transient modeling scheme for full-cycle design of the 12-pulse PSR rectifier

PurposeThis paper aims to propose a novel multiple transient modeling scheme for the 12-pulse phase-shifting reactor (PSR) rectifier to enhance the efficiency of full-cycle design evaluation.Design/methodology/approachThe detailed time-domain method is adopted to model the rectifier at the behavioral layer. The diode bridges/transformer model at the architecture layer is established by using the switch function and Park transformation. The frequency domain model at the functional layer is derived with the time-varying Fourier decomposition and frequency-shifting. At the component layer, the magneto-thermal characteristics of the rectifier are analyzed with field-circuit and magnetic-thermal coupling methods. A computer-aided design program integrating multiple modeling is also developed for industrial product design.FindingsThe function layer modeling is preferred in the initial design stage, making up for the lack of modeling accuracy at the architectural layer and the lack of modeling rapidity at the behavioral layer. The component modeling is irreplaceable for the detailed evaluation in the latter design stage. The multiple modeling scheme based on the four-layer modeling helps the designers achieve high-quality products with a short development cycle.Originality/valueThe singular transient modeling cannot cover the needs of different stages in the full-cycle design evaluation. This paper fills this gap with a novel multiple modeling scheme. Meanwhile, the proposed multiple modeling scheme and developed computer-aided design program provide a great convenience for full cycle design evaluation of the 12-pulse PSR rectifier.

A Review of Additive Manufacturing Post-Treatment Techniques for Surface Quality Enhancement

Additive manufacturing (AM), also known as 3D printing, produces an object layer by layer with the application of a computer-controlled method. AM creates an object by adding material to a solid block until the finished product is created. AM manufacturing benefits including design flexibility, creativity, rapid prototyping, high productivity, reduced manufacturing cycle, etc. However, AM products have physical quality flaws such as surface roughness, inaccurate dimensioning, porosity, staircase effects, etc. Therefore, there is a need to carry out post-treatment on the AM fabricated components to correct their flaws before they can be used. Seventeen different post-treatment methods (PTM) on AM fabricated components were discussed in this review study. Each of these PTMs, however, has its advantages and disadvantages. The results obtained from the study show that chemical PTM has the ability to improve surface roughness easily, laser polishing can be used to reduce the staircase effects, and thus reduce surface roughness significantly and increase the hardness of AM fabricated component parts. Mechanical PTM helps to join the layers of AM components and improve their toughness, while subtractive machining PTM improves surface quality. Thermal PTMs are used to improve corrosion resistance, reduce surface roughness, eliminate staircase effects, etc. The discussion of various PTMs is clearly highlighted to serve as a guide for AM stakeholders.

오픈 플랫폼 호환 지능형 IoT 컴포넌트 자동 생성 도구

As IoT applications that provide AI services increase, various hardware and software that support autonomous learning and inference are being developed. However, as the characteristics and constraints of each hardware increase difficulties in developing IoT applications, the development of an integrated platform is required. In this paper, we propose a tool for automatically generating components based on artificial neural networks and spiking neural networks as well as IoT technologies to be compatible with open platforms. The proposed component automatic generation tool supports the creation of components considering the characteristics of various hardware devices through the virtual component layer of IoT and AI and enables automatic application to open platforms.

Mathematical modeling and analysis of the thermomechanical behavior of a bimetallic spherical element during technological processing with an electromagnetic impulse

The initial-boundary problem of thermomechanics for a bimetallic spherical element under homogenous non-stationary electromagnetic action is formulated. The azimuthal component of the magnetic field strength vector, temperature, and the radial component of the displacement vector were selected as key functions. To find the key functions, the approximation of their distributions in the constituent layers of the spherical element by quadratic polynomials in the radial variable is proposed. This approximation makes it possible to accurately satisfy the specified boundary conditions both on the surfaces of this element and on the surface of the connection of the component layers, where ideal electromagnetic, thermal and mechanical contacts take place. The coefficients of the polynomials approximating the key functions in the component layers of the spherical element are given by a linear combination of functions describing all given boundary conditions and integral characteristics of the key functions on both component layers. As a result, the original initial-boundary value problems for the defining functions are reduced to Cauchy problems for their integral (summed over the package of layers) characteristics. With the use of Laplace transformation in time, the general solutions of these problems under homogeneous non-stationary electromagnetic action are recorded. The change in time of radial and azimuthal stresses and stress intensity was numerically analyzed by technological processing with an electromagnetic impulse, as well as the performance and properties of the contact connection of the bimetallic spherical element were investigated.

Design of protective and high sensitivity encapsulation layers in wearable devices.

Supplementary material is available in the online version of this article at 10.1007/s11431-022-2034-y.

How to change consumer behaviours.

Changing consumer behaviour has potential benefits for health, the economy and the environment. Change is possible, and behavioural change has been the purpose of much research; nevertheless we can still observe limited success, as in the case of food in public policies or individual diets. One reason is that models driving behavioural change interventions tend to neglect some important contextual factors. The three layers of components that channel behaviour ('installations' in the material, embodied and social realms) are described here and how this channelling can be hacked, modified and leveraged to foster behavioural change. Installations scaffold and control individual and collective behaviour at each step of the behavioural path with their three-layered and partly redundant structure. This redundancy makes the channelling resilient enough to train novices and to guide and repair behaviour. The three layers, physical affordances, embodied competences and social regulation are described in detail. To change eating behaviour, installations must be adapted at all steps of behaviour, from procurement to storage, preparation, meal and disposal. This adaptation can be done through the various layers in an opportunistic way, according to the agency of those who endeavour to change behaviour (e.g. budget, time, political power, etc.) Finally the steps necessary to design behavioural change interventions leveraging installations are listed.

Аналіз теплового режиму електропровідного трубчастого елемента з тонким зовнішнім електропровідним покриттям за дії неусталеного електромагнітного поля

An electrically conductive tubular element with a thin external electri-cally conductive coating underthe action of an unsteady electromagnetic field of the radio frequency range is considered. To analyze the thermal re-gime, the initial-boundary problem of electrodynamics for a two-layer conductive non-ferromagnetic hollow cylinder under the action of an ex-ternal non-stationary electromagnetic field is formulated. The electromag-netic field is given by the values of the axial component of the magnetic field intensity vector on the inner and outer surfaces of the cylinder. To construct the general solution of the formulated initial-boundary value problem, a quadratic approximation of the key function (the axial compo-nent of the magnetic field intensity vector) along the radial coordinate in each constituent layer (base and cover) of the hollow cylinder was used. As a result, the original initial-boundary value problem for the key function is reduced to the Cauchy problem in terms of the time variable for the charac-teristics of the key function integral over the radial coordinate. The coeffi-cients of the approximation polynomials are presented through the integral characteristics of the key function and its given values on the inner and outer surfaces of the cylinder as a function of time. The solution of the Cauchy problem is obtained using the integral Laplacetransform. Expres-sions of the key function in each component layer of the cylinder are rec-orded in the form of quadratic polynomials, the coefficients of which are convolutions of functions describing the given limit values of the key func-tion on the inner and outer surfaces of the cylinder and homogeneous solu-tions of the Cauchy problem on integral characteristics. Expressions of the key function and Joule heat in the base and coating of the considered tubu-lar element under the action of an unsteady electromagnetic field in the mode with a pulsed modulating signal were obtained on the basis of gen-eral solutions for homogeneous non-stationary electromagnetic action. A computer analysis of the change in time and thickness of the constituent layers of this tubular element of the axial component of the vector of mag-netic field intensity and Joule heat was carried out.

Evolutionary Multitasking Multilayer Network Reconstruction

Due to the multilayer nature of real-world systems, the problem of inferring multilayer network structures from nonlinear and complex dynamical systems is prominent in many fields, including engineering, biological, physical, and computer sciences. Many network reconstruction methods have been proposed to address this problem, but none of them consider the similarities among network reconstruction tasks at different component layers, which are inspired by topology correlations and dynamic couplings among different component layers. This article develops an evolutionary multitasking multilayer network reconstruction framework to make use of the correlations among different component layers to improve the reconstruction performance; we refer to this framework as EM2MNR. In EM2MNR, the multilayer network reconstruction problem is first established as a multitasking multilayer network reconstruction problem, where the goal of each task is to reconstruct the network structure of a component layer. In addition, multitasking multilayer network reconstruction problems are high dimensional, but existing evolutionary multitasking algorithms may have poor performance when dealing with optimization problems with a high-dimensional search space. Inspired by the sparsity of multilayer networks, EM2MNR employs the restricted Boltzmann machine to extract low effective features from the original decision space and then decides whether to conduct knowledge transfer on these features. To verify the performance of EM2MNR, this article also designs a test suite for multilayer network reconstruction problems. The experimental results demonstrate the significant improvement obtained by the proposed EM2MNR framework on 96 multilayer network reconstruction problems.

Optimization of electric vehicle sound package based on LSTM with an adaptive learning rate forest and multiple-level multiple-object method

The sound absorption and sound insulation performance of an acoustic package (AP) system directly affect the noise, vibration and harshness performance of a vehicle. Numerous studies have studied the optimization of vehicle sound package, however, there are two deficiencies in the current research of sound package: (1) The noise transmission path of acoustic package is complex and hierarchical. Most of the related works focus on the data-driven part while ignoring the knowledge attributes behind the acoustic package design problem, which limits the further improvement of prediction and optimization of acoustic package performance. (2) In using intelligent neural networks-based methods such as long short-term memory (LSTM), reducing the learning rate during training gradually narrows the search interval of a solution, and adjusting the learning rate in a small range may tend to trap local optima. In this study, a knowledge- and data-driven approach is proposed for the development of acoustic package systems. A multiple-level multiple-object method is proposed as the knowledge model, and a multilayer structure of the acoustic package system that contains the system, subsystem and component layers is developed. In addition, an improved long short-term memory model based on an adaptive learning rate forest, which can increase and decrease the learning rate adaptively, is proposed as the data-driven model. The knowledge- and data-driven method is applied to optimize the sound absorption and insulation of the acoustic package system. In the experimental validation, the effectiveness and robustness of the proposed method outperformed the traditional direct mapping method and the conventional long short-term memory method.

Mixture of Networks for Clustering Categorical Data: A Penalized Composite Likelihood Approach

One of the challenges in clustering categorical data is the curse of dimensionality caused by the inherent sparsity of high-dimensional data, the records of which include a large number of attributes. The latent class model (LCM) assumes local independence between the variables in clusters, and is a parsimonious model-based clustering approach that has been used to circumvent the problem. The mixture of a log-linear model is more flexible but requires more parameters to be estimated. In this research, we recognize that each categorical observation can be conceived as a network with pairwise linked nodes, which are the response levels of the observation attributes. Therefore, the categorical data for clustering is considered a finite mixture of different component layer networks with distinct patterns. We apply a penalized composite likelihood approach to a finite mixture of networks for sparse multivariate categorical data to reduce the number of parameters, implement the EM algorithm to estimate the model parameters, and show that the estimates are consistent and satisfy asymptotic normality. The performance of the proposed approach is shown to be better in comparison with the conventional methods for both synthetic and real datasets.

Efficient Rigorous Coupled-Wave Analysis Simulation of Mueller Matrix Ellipsometry of Three-Dimensional Multilayer Nanostructures.

Mueller matrix ellipsometry (MME) is a powerful metrology tool for nanomanufacturing. The application of MME necessitates electromagnetic computations for inverse problems of metrology determination in both the conventional optimization process and the recent neutral network approach. In this study, we present an efficient, rigorous coupled-wave analysis (RCWA) simulation of multilayer nanostructures to quantify reflected waves, enabling the fast simulation of the corresponding Mueller matrix. Wave propagations in the component layers are characterized by local scattering matrices (s-matrices), which are efficiently computed and integrated into the global s-matrix of the structures to describe the optical responses. The performance of our work is demonstrated through three-dimensional (3D) multilayer nanohole structures in the practical case of industrial Muller matrix measurements of optical diffusers. Another case of plasmonic biosensing is also used to validate our work in simulating full optical responses. The results show significant numerical improvements for the examples, demonstrating the gain in using the RCWA method to address the metrological studies of multilayer nanodevices.

Tribological properties of Ni3Al matrix self-lubricating composites with a gradient composite structure prepared by laser melt deposition

As the contact part of metal-matrix self-lubricating composites during sliding friction, the friction interface layer directly affects the tribological performance of the material. However, the formation of the friction interface layer with outstanding tribological performance is limited by the friction conditions during sliding friction. To address this problem, based on the antifriction and wear resistance mechanisms of the in situ formed friction interface layer of Ni3Al matrix self-lubricating composites (NMSCs) with homogeneous solid lubricant, Ni3Al matrix self-lubricating composites with a gradient composite structure (Ni3Al-GCS) were prepared via laser melt deposition, in which each component layer contained different contents of Sn-Ag-Cu and Ti3SiC2. Dry sliding friction tests of Ni3Al-GCS against GCr15 steel balls were performed under different loading conditions. The results showed that the tribological performances of Ni3Al-GCS in the range of 4–16 N were less affected by the variation of the loading conditions than those of NMSCs. The gradient composite structure of Ni3Al-GCS could reduce the dependence of the tribological behavior on the friction conditions, resulting in excellent antifriction and wear resistance of Ni3Al-GCS in a wide load range. In addition, the gradient composite structure could reduce the sliding contact damage of the friction contact surface of Ni3Al-GCS, and contribute to the formation of friction interface layer rich in the lubrication phase and oxides, thus improving the tribological performance of Ni3Al-GCS during sliding friction. This study provides new approaches for the tribological design of metal-matrix self-lubricating composites in a wide load range.

Deformation behavior and fracture mechanism of laminated Ti/Ti-50 Nb alloy with diffusion layer

The laminated Ti /Ti-50 Nb alloy (laminated Ti-TiNb alloy) was designed and fabricated by spark plasma sintering (SPS) combined with hot rolling. TEM and EBSD were applied to investigate the microstructure and texture evolution before and after the tensile deformation. In-situ tensile tests monitored by SEM were applied to understand the fracture behavior of laminated Ti-TiNb alloy. The results indicated that the laminated structure and diffusion layer endowed the laminated Ti-TiNb alloy with enhanced strength-ductility synergy. The formation of the diffusion layer effectively strengthened the laminated Ti-TiNb alloy due to the precipitation of a large number of fine second phases. During the tensile deformation, the diffusion layer deformed in coordination with the component layers, so that the strain efficiently transferred between the Ti and the TiNb layers. Simultaneously, grain rotation in the TiNb layers was apparently promoted which suppressed premature strain concentration within the TiNb layers. An excellent strain hardening ability was achieved in the laminated Ti-TiNb alloy with diffusion layers, with a uniform elongation of 9.4%, much higher than the value calculated by the rule of mixture. At last, the relationship between interface status and fracture behavior was discussed.

(Invited) Mechanically Extreme Batteries: From Flexible to Structural

Batteries with extreme mechanical properties are attractive for unique applications. On the soft side, flexible and stretchable batteries are attractive for wide applications, such as health care and flexible electronics. It is challenging to realize high flexibility/stretchability and high energy density simultaneously. In this talk, I will talk about feasible and scalable strategies to fabricate flexible lithium-ion batteries, which can concurrently have high energy density and high mechanical flexibility, including bendability, foldability, twistability and stretchability. Inspired by the structure of animal spine, the vertebrae-like hard segments with multiple layers of conventional anode/separator/cathode stack to offer energy storage are interconnected by the soft components as marrow with the monolayer stack to provide flexibility. On the other hand, mechanically strong batteries are also important as they may replace structural components in vehicles and aircrafts for lightweighting. I will discuss a scalable and feasible tree-root-like lamination at the electrode/separator interface, which effectively transfers load between different layers of battery components and thus dramatically enhances the flexural modulus of pouch cells from 0.28 to 3.1 GPa. A graphite/LiNi0.5Mn0.3Co0.2O2 full cell with such interfacial lamination delivers a steady discharge capacity of 148.6 mAh g−1 at C/2 and 95.5% retention after 500 cycles. A prototype of “electric wings” is also demonstrated, which allows an aircraft model to fly steadily.