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Parameter identification is a technique which aims at determining material or other process parameters based on a combination of experimental and numerical techniques. In recent years, heuristic approaches, such as genetic algorithms (GAs), have been proposed as possible alternatives to classical identification procedures. The present work shows that particle swarm optimization (PSO), as an example of such methods, is also appropriate to identification of inelastic parameters. The paper aims to discuss these issues.

PSO is a class of swarm intelligence algorithms which attempts to reproduce the social behaviour of a generic population. In parameter identification, each individual particle is associated to hyper-coordinates in the search space, corresponding to a set of material parameters, upon which velocity operators with random components are applied, leading the particles to cluster together at convergence.

PSO has proved to be a viable alternative to identification of inelastic parameters owing to its robustness (achieving the global minimum with high tolerance for variations of the population size and control parameters), and, contrasting to GAs, higher convergence rate and small number of control variables.

PSO has been mostly applied to electrical and industrial engineering. This paper extends the field of application of the method to identification of inelastic material parameters.

This study aims to focus on the submicron particles (with diameter of 0.2-1.0 μm) of the ambient air from a coal-fired power plant. A systematic examination of their morphology, particle size and chemical element will be analyzed, so as to provide more scientific information and theoretical basis for the formation and control method of inhalable particles, as well as data support for environmental impact and ecological effects assessments.

In this paper, the morphology, size distribution and elemental characteristics of submicron particles from ambient air of a coal-fired power plant are studied by single particle analysis.

The results show that atmospheric particles in coal-fired power plant are mainly spherical particles, and most of them are soot aggregates adhered or coated with other particles with few rectangle particles. The particles collected in the afternoon and evening are mainly of spherical particles, and small-sized particles collected in the morning are mainly spherical ones, while the overall concentration is larger than that of the spherical particles in the size range above 0.5 μm. The results indicated that the larger-sized spherical particles have a lower concentration.

Coal-fired power plants are still the main supply of electricity in China, but the inhalable particles, especially sub-micron particles (0.1-1.0 μm) cannot be effectively captured by the dust removal device from the coal-fired power plant. Thus, a large amount of inhalable particles is emitted into the atmosphere, becoming the major air pollutants in China.

Smoke and dust emissions from industrial furnaces can do great harm to the environment and human health. This paper aims to analyze the morphology, diameter and elements of the submicron particles from the furnace flues and the nearby ambient air by using two typical industrial furnaces, the sintering furnace and the electric furnace.

Two typical industrial furnaces, the sintering furnace and the electric furnace, were chosen in this study, to analyze the morphology, diameter and elements of the submicron particles from the furnace flues and the near-by ambient air.

The results show that the particles from the two furnaces are mainly in the small sizes of 0.3-0.6 μm. Particles from sintering plant flue are mainly spherical and rich in K and Cl, whereas those from the electric plant flue are mainly particles rich in metal elements, such as Zn and Fe, and have different morphology.

The particles in the atmosphere nearby the two furnaces contain aged particles from the flue, lots of spherical particles, rectangle particles and various aggregations. The elements of those particles are complex.

The purpose of this paper is to study the effect of particle shapes (spherical particle and nonspherical fiber) on their orientation distributions in indoor environment.

This paper adopted a particle model to predict the fibrous particle flow and distribution, and analyzed the orientation distributions of nonspherical fiber particles and spherical particles in airflows like indoor places. Fokker-Planck model was employed to solve the orientation behavior of nonspherical fiber particles.

The simulation results discover that the nonspherical airborne fiber particles have very different characteristics and behaviors and their orientation distributions are totally different from the uniform distribution of spherical particles. The investigation of the particle orientation tensor and orientation strength indicates that the airflow field becomes more anisotropic due to the suspended fibers. The airborne fiber particles increase the viscosity of the room airflow due to the fiber induced additional viscosity.

Orientation tensor, strength and additional viscosity in fibrous flow are seldom investigated indoor. This research reveals that the particle shape has to be considered in the analysis of particle transport and distribution in indoor places as most suspended indoor particles are nonspherical.

Embedded passives account for a very large part of today's electronic assemblies. This is particularly true for products such as cellular phones, camcorders, computers, and several critical defence devices. Market pressures for new products with more features, smaller size and lower cost demand smaller, compacter, simpler substrates. An obvious strategy is to reduce the number of surface mounted passives by embedding them in the substrate. In addition, current interconnect technology to accommodate surface mounted passives imposes certain limits on board design which constrain the overall system speed. Embedding passives is one way to minimize the functional footprint while at the same time improving performance. The purpose of this paper is to describe the development of a thin film technology based on ferroelectric‐epoxy polymer‐based flake‐free resin coated copper capacitive (RC3) nanocomposites to manufacture multilayer embedded capacitors.

This paper discusses thin film technology based on RC3 nanocomposites. In particular, recent developments in high capacitance, large area, thin film passives, and their integration in system in a package (SiP) are highlighted.

A variety of RC3 nanocomposite thin films ranging from 8 to 50 microns thick were processed on copper substrates by liquid coating. Multilayer embedded capacitors resulted in high capacitances of 16‐28 nF. The fabricated test vehicle also included two embedded resistor layers with resistances in the range of 15 Ω to 100 kΩ. To enable high performance devices, an embedded resistor must meet certain tolerances. The embedded resistors can be laser trimmed to a tolerance of <5 percent, which is usually acceptable for most applications. An extended embedded passives solution has been demonstrated, both through its high wireability designs and package performance, to be perfectly suited for SiP applications.

This case study designed and fabricated an eight layer high density internal passive core and subsequently applied fine geometry three buildup layers to form a 3‐8‐3 structure. The passive core technology is capable of providing up to six layers of embedded capacitance and could be extended further.

A thin film technology based on ferroelectric‐epoxy polymer‐based flake‐free RC3 nanocomposites was developed to manufacture multilayer embedded capacitors. The overall approach lends itself to package miniaturization because capacitance can be increased through multiple layers and reduced thickness to give the desired values in a smaller area.

The purpose of this paper is to solve the problem that the location of the initiation point cannot be measured accurately in the shallow underground space, this paper proposes a method, which is based on fusion of multidimensional vibration sensor information, to locate single shallow underground sources.

First, in this paper, using the characteristics of low multipath interference and good P-wave polarization in the near field, the adaptive covariance matrix algorithm is used to extract the polarization angle information of the P-wave and the short term averaging/long term averaging algorithm is used to extract the first break travel time information. Second, a hybrid positioning model based on travel time and polarization angle is constructed. Third, the positioning model is taken as the particle update fitness function of quantum-behaved particle swarm optimization and calculation is performed in the hybrid positioning model. Finally, the experiment verification is carried out in the field.

The experimental results show that, with root mean square error, spherical error probable and fitness value as evaluation indicators, the positioning performance of this method is better than that without speed prediction. And the positioning accuracy of this method has been improved by nearly 30%, giving all of the three tests a positioning error within 0.5 m and a fitness less than 1.

This method provides a new idea for high-precision positioning of shallow underground single source. It has a certain engineering application value in the fields of directional demolition of engineering blasting, water inrush and burst mud prediction, fuze position measurement, underground initiation point positioning of ammunition, mine blasting monitoring and so on.

The purpose of this paper is to carry out a design-optimization analysis of the recently proposed side-vent-channel concept/solution for mitigation of the blast loads resulting from a shallow-buried mine detonated underneath a light tactical vehicle. Within this concept/solution, side-vent-channels attached to the V-shaped vehicle underbody are used to promote venting of ejected soil and supersonically expanding gaseous detonation products. This effect generates a downward thrust on the targeted vehicle, helping the vehicle survive mine-detonation-induced impulse loading.

The utility and the blast-mitigation capacity of this concept are investigated computationally using coupled finite-element/discrete-particle computational methods and tools. To maximize the blast-mitigation capacity of the solution (as defined by a tradeoff between the maximum reductions in the detonation-induced total momentum transferred to, and the acceleration acquired by, the target vehicle), the geometry and size of the side-vent-channel solution are optimized.

It is found that by optimizing the shape and size of the side-vent-channels, their ability to mitigate blast can be improved, but the overall blast-mitigation potential of the side-vent-channel solution remains relatively modest.

To the authors’ knowledge, the present work is the first attempt to combine the finite-element/discrete-particle analysis with optimization in order to refine the side-vent-channel blast-mitigation concept.

The purpose of this paper is to propose a method of qualitative ferrographic analysis by quantitative parameters of wear debris characteristics.

The amount of the wear debris needed for analysis on the ferrogram made by rotary ferrograph is discussed based on the theory of debris group. Quantitative parameters are constituted to express the characteristics of wear debris group, and correlation coefficients are employed to establish the relationship between wear debris and wear condition. The reliability of the method was verified by wear test experiments and ferrographic analysis.

The wear condition of machines should be determined by studying all the debris together as a group rather than by focusing on individual debris. In the proposed method, the qualitative analysis result is obtained by synthetic analysis of quantitative parameters of wear debris characteristics using a computer program, which makes the judgment of the wear system condition more objective and precise.

In the procedure of wear condition monitoring by the proposed method, because the weight factors and correlation coefficients introduced in this paper are determined according to the experiences deriving from practice among mining machinery, further rectifications may be needed if they are applied to other industrial field.

The paper illustrates a more objective and precise ferrographic analysis method for wear condition monitoring.

This paper aims to show how collective embodiment with physical objects (i.e. props) support young children’s learning through the construction of liminal blends that merge physical, virtual and conceptual resources in a mixed-reality (MR) environment..

Building on Science through Technology Enhanced Play (STEP), we apply the Learning in Embodied Activity Framework to further explore how liminal blends can help us understand learning within MR environments. Twenty-two students from a mixed first- and second-grade classroom participated in a seven-part activity sequence in the STEP environment. The authors applied interaction analysis to analyze how student’s actions performed with the physical objects helped them to construct liminal blends that allowed key concepts to be made visible and shared for collective sensemaking.

The authors found that conceptually productive liminal blends occurred when students constructed connections between the resources in the MR environment and coordinated their embodiment with props to represent new understandings.

This study concludes with the implications for how the design of MR environment and teachers’ facilitation in MR environment supports students in constructing liminal blends and their understanding of complex science phenomena.

This paper presents the results of a Discrete Element Method study on the influence of particle shape on the strength and deformation behaviour of two dimensional assemblages of ellipse‐shaped particles. Assemblages of particles with varying individual particle aspect ratio were formed with a preferred bedding plane, isotropically compressed with varying isotropic confining stresses and then sheared with biaxial compression. The results indicate that Discrete Element analysis using two dimensional ellipse‐shaped particles produces mechanical behaviour which is similar both quantitatively and qualitatively to the behaviour of real granular materials. Even small particle out‐of‐roundness increases the observed macroscopic strength significantly. In systems composed of flatter particles, particle rotations are greatly inhibited. Decomposing relative contact displacements into contributions due to particle rotation and translation demonstrates that most of the displacements in round particle systems are due to individual particle rotation.