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Article
Publication date: 1 February 1992

M.J. Remmler, A. Mödl and F. Hermann

This paper describes ways of simplifying the equations characterising the equilibrium shape of reflowed solder in the interconnection of TAB (Tape Automated Bonding) and…

Abstract

This paper describes ways of simplifying the equations characterising the equilibrium shape of reflowed solder in the interconnection of TAB (Tape Automated Bonding) and MCR (Moulded Carrier Ring) components with negligible loss in accuracy. A drastic reduction of the numerical effort necessary to calculate the solder volume for fine pitch devices is achieved. The equations are applied to TAB and MCR packages which are hotbar‐soldered to a substrate. The results of these calculations are in good agreement with experimental data.

Details

Soldering & Surface Mount Technology, vol. 4 no. 2
Type: Research Article
ISSN: 0954-0911

Article
Publication date: 11 October 2021

Manuel Tironi, Katherine Campos-Knothe, Valentina Acuña, Enzo Isola, Cristóbal Bonelli, Marcelo Gonzalez Galvez, Sarah Kelly, Leila Juzam, Francisco Molina, Andrés Pereira Covarrubias, Ricardo Rivas, Beltrán Undurraga and Sofía Valdivieso

Based on the research, the authors identify how four key concepts in disaster studies—agency, local scale, memory and vulnerability—are interrupted, and how these…

Abstract

Purpose

Based on the research, the authors identify how four key concepts in disaster studies—agency, local scale, memory and vulnerability—are interrupted, and how these interruptions offer new perspectives for doing disaster research from and for the South.

Design/methodology/approach

Meta-analysis of case studies and revision of past and current collaborations of authors with communities across Chile.

Findings

The findings suggest that agency, local scale, memory and vulnerability, as fundamental concepts for disaster risk reduction (DRR) theory and practice, need to allow for ambivalences, ironies, granularization and further materializations. The authors identify these characteristics as the conditions that emerge when doing disaster research from within the disaster itself, perhaps the critical condition of what is usually known as the South.

Originality/value

The authors contribute to a reflexive assessment of fundamental concepts for critical disaster studies. The authors offer research-based and empirically rich redefinitions of these concepts. The authors also offer a novel understanding of the political and epistemological conditions of the “South” as both a geography and a project.

Details

Disaster Prevention and Management: An International Journal, vol. 31 no. 3
Type: Research Article
ISSN: 0965-3562

Keywords

Article
Publication date: 20 April 2010

Hugo Medellin, Jonathan Corney, James Ritchie and Theodore Lim

This paper aims to investigate automatic assembly planning for robot and manual assembly.

Abstract

Purpose

This paper aims to investigate automatic assembly planning for robot and manual assembly.

Design/methodology/approach

The octree decomposition technique is applied to approximate a computer‐aided design model with an octree representation which is then used to generate robot and manual assembly plans. An assembly planning system able to generate assembly plans was developed to build these prototype models.

Findings

Octree decomposition is an effective assembly planning tool. Assembly plans can automatically be generated for robot and manual assembly using octree models.

Research limitations/implications

One disadvantage of the octree decomposition technique is that it approximates a part model with cubes instead of using the actual model. This limits its use and applications when complex assemblies must be planned, but in the context of prototyping can allow a rough component to be formed which can later be finished by hand.

Practical implications

Assembly plans can be generated using octree decomposition, however, new algorithms must be developed to overcome its limitations.

Originality/value

This paper has proved that the octree decomposition technique is an effective assembly planning tool. As a result, an assembly planning system has been developed. Assembly plans for automatic and manual assembly can be generated automatically by the proposed system, which is a novelty since there are no fully automatic assembly planning systems for manual assembly reported in the literature.

Details

Assembly Automation, vol. 30 no. 2
Type: Research Article
ISSN: 0144-5154

Keywords

Article
Publication date: 26 October 2018

Zulfiqar Ali Raza, Faiza Anwar, Irshad Hussain, Sharjeel Abid, Rashid Masood and Hafiz Shahzad Maqsood

This study aimed to present fabrication of novel poly(lactic acid) (PLA) mediated chitosan nanoparticles (CNPs) and their impregnation on cotton fabric for enhanced…

Abstract

Purpose

This study aimed to present fabrication of novel poly(lactic acid) (PLA) mediated chitosan nanoparticles (CNPs) and their impregnation on cotton fabric for enhanced antibacterial and physical properties.

Design/methodology/approach

The PLA-CNPs were characterized using scanning electron microscopy, energy dispersive x-ray spectroscopy, Fourier transform infrared (FTIR) spectroscopy and zeta size analysis. The prepared PLA-CNPs were impregnated on cotton fabric via pad-dry-cure method. The finished cotton fabric was then characterized for its antibacterial activity, functional and other physical textile properties.

Findings

The spectral and optical properties demonstrate that the NPs expressed spherical morphologies with an average particle diameter of 88.02 nm. The antibacterial activity of treated fabrics ranged between 75 and 90 per cent depending on the concentration of PLA-CNPs.

Practical implications

Because of enhanced awareness and desire for ecofriendly products, the use of sustainable and functional textiles is increasing day by day. For the said purpose, industries are using different chemical treatments to achieve desired end functionality. Currently, different synthetic antibacterial agents are in practice, but they lack sustainable approach to save the environment. In this study, the researchers have developed PLA mediated CNPs for sustainable antibacterial and physical properties of treated cotton fabric.

Originality/value

To the best of the authors’ knowledge, this is first attempt to fabricate PLA-incorporated CNPs for application on cotton fabric followed by a detailed characterization.

Details

Pigment & Resin Technology, vol. 48 no. 2
Type: Research Article
ISSN: 0369-9420

Keywords

Article
Publication date: 30 October 2019

Morteza Behzadnasab, Ali Akbar Yousefi, Dariush Ebrahimibagha and Farahnaz Nasiri

With recent advances in additive manufacturing (AM), polymer-based three-dimensional (3D) printers are available for relatively low cost and have found their way even in…

Abstract

Purpose

With recent advances in additive manufacturing (AM), polymer-based three-dimensional (3D) printers are available for relatively low cost and have found their way even in domestic and educational uses. However, the optimum conditions for processing and post-processing of different materials are yet to be determined. The purpose of this paper is to examine the effects of printing temperature, pattern and annealing conditions on tensile strength and modulus of samples printed with polylactic acid (PLA).

Design/methodology/approach

This study focuses on fused deposition modelling according to ISO/ASTM 52900 material extrusion AM. To print parts with maximum mechanical properties, the printing variables must be optimised. To determine the printing and annealing condition on physical and mechanical properties of PLA-based parts, dogbone-shaped tensile samples were printed at four different nozzle temperatures and five different filling patterns embedded in a 3D printing software. The samples were further annealed at three different temperatures for three different time intervals. The mechanical properties were evaluated and the changes in mechanical properties were analysed with the help of rheometrical measurements.

Findings

The results showed that printing condition has a significant influence on final properties, for example, the strain at break value increases with increasing nozzle temperature from 34 to 56 MPa, which is close to the value of the injected sample, namely, 65 MPa. While tensile strength increases with printing temperature, the annealing process has negative effects on the mechanical properties of samples.

Originality/value

The authors observed that traditional findings in polymer science, for example, the relationship between processing and annealing temperature, must be re-evaluated when applied in 3D printing because of major differences in processing conditions resulting from the layer-by-layer manufacturing.

Details

Rapid Prototyping Journal, vol. 26 no. 2
Type: Research Article
ISSN: 1355-2546

Keywords

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