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This paper presents an algorithm for automatic generation of graded initial quadrilateral meshes targeted for the finite element analysis of metal‐forming processes. Meshing the domain geometry deals with a universe of shapes, and the procedure therefore takes into account the initial geometry of the billet. A grid‐based approach is utilised for generating an initial coarse mesh with well‐shaped (internal) elements, and in cases where non‐rectangular shapes are to be discretized, linking with the boundary is performed on the basis of constrained Delaunay triangulation. By analysing the contact situation between dies and mesh, an attempt is made to identify regions where plastic deformation is likely to be concentrated during the early stages of processing, and accordingly refinement of the mesh is performed locally by elemental subdivision. Simulation examples for closed‐die forging, forward rod and backward can extrusion substantiate the feasibility of this approach in terms of lowering the overall calculation error and limiting the interference between mesh and die.

This paper gives a review of the finite element techniques (FE) applied in the area of material processing. The latest trends in metal forming, non‐metal forming and powder metallurgy are briefly discussed. The range of applications of finite elements on the subjects is extremely wide and cannot be presented in a single paper; therefore the aim of the paper is to give FE users only an encyclopaedic view of the different possibilities that exist today in the various fields mentioned above. An appendix included at the end of the paper presents a bibliography on finite element applications in material processing for the last five years, and more than 1100 references are listed.

The Expanded Metal Co. Limited, Caxton Street, London, S.W.1, have extended their range of mesh materials available to engineers and designers by introducing the first high density polyethylene mesh.

Voiding in BGA assembly using SN63 solder bumps is primarily introduced at board‐level assembly stage. On the pretinned PCBs, voiding of BGA joints increases with increasing solvent volatility, increasing metal content and increasing reflow temperature, and with decreasing powder size. This can be explained by a viscosity dictated flux‐exclusion‐rate model. In this model, a higher viscosity in the fluxing medium at reflow temperature could hinder the exclusion of flux from the interior of the molten solder, hence increase the chance of outgassing due to the increasing amount of entrapped flux, and consequently result in higher voiding in BGA assembly. Flux activity and reflow atmosphere appear to have a negligible effect on voiding when the solderability of the immobile metallisation is not a concern. An increase in void content is accompanied by an increase in the fraction of large voids. This suggests that, similar to voiding phenomena in the SMT process, factors causing voiding in BGA will have an even greater impact on joint reliability than shown by the total‐void‐volume analysis results.

The purpose of this paper is to fabricate a high-performance filtration electrospun nanofiber membrane with antibacterial function. The Ag nanoparticles (AgNPs) gotten by reducing AgNO₃ act as antimicrobial agent. Then the AgNPs/Polyacrylonitrile (AgNPs/PAN) composite nanofiber membrane was prepared by electrospinning.

The electrospun Ag/PAN composite membrane was prepared by one step, in which the Ag particles were acting as antibacterial agent and PAN nanofiber as the upholder of the composite mat. AgNPs were obtained by reducing AgNO3 in N,N-Dimethylformamide (DMF) solution at high temperature. Meanwhile, the PAN particles were added to DMF solution and dissolved. Then the Ag/PAN nanofiber was obtained by electrospinning.

The thinner nanofiber can be produced with PAN concentration of 12 per cent and AgNPs concentration of 10 per cent. Finally, the filtration resistance of the composite membrane with antibacterial property is as high as 99.1 per cent, and the filtration efficiency is only 83 Pa. Therefore, the AgNPs/PAN composite membrane is the ideal choice for air filtration with antibacterial property.

The AgNPs/PAN composite nanofiber membrane has high filtration performance for particulate matter (PM)25 and outstanding antibacterial property to Escherichia coli and Staphylococcus aureus, which can be used with masks, air-conditioning filters (including car air-conditioning filters), window screening and other similar objects.

This paper focuses on the potential applications of eco-features in Vietnamese traditional folk houses to contemporary high-rise housing. One of the main characteristics of traditional folk houses is that they are designed with a deep understanding of and respect for nature. This type of housing also expresses the way of life of its users, having evolved over generations while adapting to their needs, culture, and environment. Whereas the traditional Vietnamese houses can be an important source in the creation of a Vietnamese architectural identity, the design-with-nature approach and its unique characteristics are, however, scarcely found in the contemporary high-rise housing in Vietnam.

The objective of this research is to investigate the potential applications of eco-features in Vietnamese traditional folk houses to contemporary high-rise urban housing. Initially, this study examines the unique spatial characteristics of the traditional folk houses typical in northern Vietnam. In particular, four houses at the Duong Lam Village in northern Vietnam are reviewed. Some of the ecological design elements are extracted from the spatial composition of the typical Vietnamese folk houses in relation to the local climate conditions and the Vietnamese lifestyle (vernacular culture). Finally, this paper attempts to develop new housing models in urban Vietnam, employing the ecological elements learned from the preceding assessment.

Accounting for seventy five percent of urban housing in Vietnam, street houses refer to a mixed-use housing typology that emerged in the 17th century. Such housing has evolved in response to Vietnam's unique culture and environmental conditions. Residential and commercial functions are integrated in a flexible and expandable manner, creating a variety of compositional possibilities in spatial layouts. In addition, transitional spaces such as courtyards, balconies, loggia, and terraces provide shading, cooling, and ventilation effects throughout the building. As one of the most adaptive and popular urban dwellings, the street house has promoted daily domestic activities and the identities of Vietnamese urban areas. However, such valuable aspects have received less attention in many recent urban developments in Vietnam. As such, the goal of this study is to identify and analyze the unparalleled ingenuity of the street house, particularly focusing on its spatial flexibility and environmental responsiveness. Furthermore, this study is intended to apply analytical investigations to the design of contemporary high-rise housing in Vietnam.

With such purposes, this paper is structured in two sequences. In the first phase, typological characteristics of the street house are studied; a field survey is performed to address the evolutionary transformation of the street house. By studying several precedents in Vietnam, our study focused on understanding the ways in which spaces are manipulated and in which diverse indoor and outdoor spaces are created. In addition, passive environmental systems are studied, meaning systems that are integrated with the spaces in order to control the microclimatic conditions of the house. Next, the morphology of the forms and space components are carefully examined through the contemporary examples of street house models in Vietnam. Especially, the flexible nature of the street house, in terms of spatial composition and expansion, is identified. In the second phase, a transition from the street house to high-rise housing is explored based on the previous analytical studies; compositional logic for arranging internal and external spaces are outlined to generate typological unit plans of street houses. Out of diverse design possibilities, an exemplary high-rise building is proposed to address the notions of spatial flexibility and integrated passive systems that are found in the street house. Ultimately, the proposed design aims to enrich dwelling environments for new high-rise urban communities.

An easy and robust grid‐based approach is proposed to construct the fully hexahedral mesh in three‐dimensional case and its application for the mesh regeneration or remeshing during the finite element simulation of a metal forming process is presented to show the validity and effectiveness of the scheme. The proposed scheme enables the construction of the provisional mesh by superimposing the regular cubical grid over the object to be meshed and removing the exterior grid points and cells. Because the constructed provisional mesh has the discrete rugged boundary that is quite different from the boundary geometry of the object to be meshed, the nodes on the boundary of the provisional mesh are projected onto the object boundary. The main disadvantage of the mesh constructed by grid‐based approaches is its severely distorted elements on the boundary owing to the projection of the rugged boundary onto the object boundary. In order to improve the quality of boundary elements, some layers of elements on the boundary surface are constructed and the nodes are repositioned by mesh smoothing. Consequently, the quality of boundary elements is effectively improved.

This paper gives a review of the finite element techniques (FE) applied in the area of material processing. The latest trends in metal forming, non‐metal forming, powder metallurgy and composite material processing are briefly discussed. The range of applications of finite elements on these subjects is extremely wide and cannot be presented in a single paper; therefore the aim of the paper is to give FE researchers/users only an encyclopaedic view of the different possibilities that exist today in the various fields mentioned above. An appendix included at the end of the paper presents a bibliography on finite element applications in material processing for 1994‐1996, where 1,370 references are listed. This bibliography is an updating of the paper written by Brannberg and Mackerle which has been published in Engineering Computations, Vol. 11 No. 5, 1994, pp. 413‐55.

This study aims to present a novel hydrostatic squeeze film-metal mesh journal bearing (HS-MMJB), which uses both hydrostatic squeeze film damper (HSFD) and metal mesh damper (MMD), to suppress the vibration of rotor-bearing systems.

The lubrication equations were introduced to calculate the dynamic characteristics of HS-MMJB, and the response analyses of rotor systems were carried out. Experiments were conducted to study the vibration reduction of a rotor system with HS-MMJB. In addition, experiments for different oil supply pressures in the HS-MMJB were conducted.

The theoretical and experimental results show that the HS-MMJB exhibits excellent damping and vibration attenuation characteristics. Moreover, the stability of the rotor system can be improved by controlling the oil supply pressure.

There is a dearth of research on vibration characteristics of rotor system support by journal bearing combining HSFD and MMD. Moreover, the active oil pressure control is implemented to improve the stability of rotor system.