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Open Access
Article
Publication date: 30 July 2021

Michał Ciałkowski, Aleksander Olejnik, Magda Joachimiak, Krzysztof Grysa and Andrzej Frąckowiak

To reduce the heat load of a gas turbine blade, its surface is covered with an outer layer of ceramics with high thermal resistance. The purpose of this paper is the selection of…

Abstract

Purpose

To reduce the heat load of a gas turbine blade, its surface is covered with an outer layer of ceramics with high thermal resistance. The purpose of this paper is the selection of ceramics with such a low heat conduction coefficient and thickness, so that the permissible metal temperature is not exceeded on the metal-ceramics interface due to the loss ofmechanical properties.

Design/methodology/approach

Therefore, for given temperature changes over time on the metal-ceramics interface, temperature changes over time on the inner side of the blade and the assumed initial temperature, the temperature change over time on the outer surface of the ceramics should be determined. The problem presented in this way is a Cauchy type problem. When analyzing the problem, it is taken into account that thermophysical properties of metal and ceramics may depend on temperature. Due to the thin layer of ceramics in relation to the wall thickness, the problem is considered in the area in the flat layer. Thus, a one-dimensional non-stationary heat flow is considered.

Findings

The range of stability of the Cauchy problem as a function of time step, thickness of ceramics and thermophysical properties of metal and ceramics are examined. The numerical computations also involved the influence of disturbances in the temperature on metal-ceramics interface on the solution to the inverse problem.

Practical implications

The computational model can be used to analyze the heat flow in gas turbine blades with thermal barrier.

Originality/value

A number of inverse problems of the type considered in the paper are presented in the literature. Inverse problems, especially those Cauchy-type, are ill-conditioned numerically, which means that a small change in the inputs may result in significant errors of the solution. In such a case, regularization of the inverse problem is needed. However, the Cauchy problem presented in the paper does not require regularization.

Details

International Journal of Numerical Methods for Heat & Fluid Flow, vol. 32 no. 1
Type: Research Article
ISSN: 0961-5539

Keywords

Article
Publication date: 1 October 1999

Hai‐Ru Long

The aim of this study is to investigate the water (moisture vapor and liquid) transfer properties of two‐layer weft knitted fabric and some related factors. Some experimental…

765

Abstract

The aim of this study is to investigate the water (moisture vapor and liquid) transfer properties of two‐layer weft knitted fabric and some related factors. Some experimental fabrics with specific yarns and stitch densities were prepared. Water vapor permeability rate through the fabrics and liquid water transfer from inner to outer layers were measured. The results show that the permeability rate is closely related to the porosity within the fabric while the transfer depends mainly upon the water absorption properties of the fibers on the two layers and degree of their difference.

Details

International Journal of Clothing Science and Technology, vol. 11 no. 4
Type: Research Article
ISSN: 0955-6222

Keywords

Article
Publication date: 1 June 2005

Peng Li, Calvin Lee and Brian Corner

To explore three‐dimensional scanning technology in capturing the shape of inflated parachutes for accurate estimation of surface area and volume.

2786

Abstract

Purpose

To explore three‐dimensional scanning technology in capturing the shape of inflated parachutes for accurate estimation of surface area and volume.

Design/methodology/approach

The volume and surface area of an inflated round parachute are important parameters for the design and analysis of its performance. However, it is difficult to acquire the three‐dimensional (3D) surface shape of a parachute due to its flexible fabric and dynamic movement. This paper presents how we collect 3D data with a laser scanner and calculate volume and surface area of parachutes from their scans. The necessary data clean and approximation steps with non‐uniform B‐spline function are introduced and implemented. Numerical integration methods are employed to estimate surface area and volume. The approximation of the parachute based on an ellipsoid is compared with the numerical integration approach in their volumes and surface areas.

Findings

It is found that 3D scanning technology, with help of mathematic program developed, provides a feasible mean to estimate the surface area and volume of inflated parachutes. The numerical integration method derived in this paper is reliable and robust for the computation.

Originality/value

It is the first time that the 3D shape of an inflated parachute has been scanned with a laser scanner. The mathematical methods developed for processing of scan data are useful for others who use 3D scanning technology. The computational approach and results of surface area and volume of inflated parachutes are valuable to parachute performance modeling and design community.

Details

Engineering Computations, vol. 22 no. 4
Type: Research Article
ISSN: 0264-4401

Keywords

Article
Publication date: 15 May 2009

Thomas Leneke, Soeren Hirsch and Bertram Schmidt

The purpose of this paper is to present a new multilayer process for three‐dimensional molded interconnect devices (3D‐MIDs) that allows the assembly of modern area array packaged…

Abstract

Purpose

The purpose of this paper is to present a new multilayer process for three‐dimensional molded interconnect devices (3D‐MIDs) that allows the assembly of modern area array packaged semiconductors.

Design/methodology/approach

A new 3D‐MID multilayer process based on local overmolding is developed. To investigate this new process, a 3D demonstrator is designed, simulated and fabricated. Various technologies such as injection molding, maskless laser assisted electroless metallization, overmolding and laser via drilling are used.

Findings

Using the new 3D‐MID multilayer process a 3D demonstrator with three metallization layers is fabricated. Injection molding simulation is utilized to ensure a feasible demonstrator design. It is shown that a surface laser treatment improves layer‐to‐layer adhesion during the process. Shear and pull tests prove the adhesion promotion. The 3D fine‐pitch‐metallization is done down to 60 μm track width. Via resistance is measured by four terminal sensing in agreement with previous results. Design rules for process compatible vias are introduced. The fabricated demonstrator is suitable for flip‐chip‐based area array packaged semiconductors.

Research limitations/implications

A proof of concept is given by the fabricated demonstrator. Further, work should include reliability tests of the multilayer structures and improvement of individual process steps.

Originality/value

The paper describes a new multilayer process for 3D‐MIDs. It overcomes existing restrictions regarding the electrical routing on 3D‐MID surfaces. The compatibility of area array packaged semiconductors with a high‐inputs/outputs count and the 3D‐MID technology is improved.

Details

Circuit World, vol. 35 no. 2
Type: Research Article
ISSN: 0305-6120

Keywords

Article
Publication date: 1 August 1999

Leo‐Paul Dana and Daniella Vignali

“There is no sound reason to believe that there will not be a single global market in air transport”. Those were the words of Sir Colin Marshall, the chairman of British Airways…

17448

Abstract

“There is no sound reason to believe that there will not be a single global market in air transport”. Those were the words of Sir Colin Marshall, the chairman of British Airways. To give the airline an image of being a global airline, the amount of £60 million had been earmarked. Simultaneously, British Airways Chief Executive Robert (Bob) Ayling wanted the firm to become the best‐managed company in Europe, by the year 2000. This case study assesses how British Airways have gone about achieving this goal.

Details

International Marketing Review, vol. 16 no. 4/5
Type: Research Article
ISSN: 0265-1335

Keywords

Article
Publication date: 1 July 1989

Multilayer coating systems used for beam‐splitters, colour conversation filters, bandpass, and heat protection filters, and for cold‐light and laser mirrors, have to be produced…

Abstract

Multilayer coating systems used for beam‐splitters, colour conversation filters, bandpass, and heat protection filters, and for cold‐light and laser mirrors, have to be produced to extremely tight tolerances.

Details

Pigment & Resin Technology, vol. 18 no. 7
Type: Research Article
ISSN: 0369-9420

Article
Publication date: 13 January 2012

Mushtaq Khan and Phill Dickens

Different metals have been processed using laser‐based solid freeform fabrication (SFF) processes but very little work has been published on the selective laser melting (SLM) of…

1850

Abstract

Purpose

Different metals have been processed using laser‐based solid freeform fabrication (SFF) processes but very little work has been published on the selective laser melting (SLM) of gold (Au). The purpose of this paper is to check the properties of gold powder and identify suitable processing parameters for SLM of 24 carat gold powder.

Design/methodology/approach

A full factorial approach was used to vary the processing parameters and identify suitable processing region for gold powder. The effects of laser processing parameters on the internal porosity of the multi‐layer parts were examined.

Findings

The gold powder was found to be cohesive in nature with apparent and tap densities of 9.3 and 10.36 g/cm3, respectively. The reflectance of gold powder was found to be 85 per cent in the infrared range. A very narrow good melting region was identified for gold powder. The balling phenomenon was observed at both low and high scan speeds. The size of droplets in the balling region tended to increase with increasing laser power and decreasing scan speeds. The porosity in gold multi‐layer parts was found to be the minimum for a laser power of 50 W and scan speed of 65 mm/s where most of the porosity was found to be inter‐layer porosity.

Originality/value

This research is the first of its kind directly processing 24 carat gold using SLM, identifying the suitable processing parameters and its effect on the internal porosity and structure of multi‐layer parts.

Details

Rapid Prototyping Journal, vol. 18 no. 1
Type: Research Article
ISSN: 1355-2546

Keywords

Book part
Publication date: 30 November 2017

Felippe de Medeiros Oliveira, Gazi Islam and Maria Laura Toraldo

Recent interest in the multimodal accomplishment of organization has focused on the material and symbolic aspects of materiality. We argue that current literature invokes diverse…

Abstract

Recent interest in the multimodal accomplishment of organization has focused on the material and symbolic aspects of materiality. We argue that current literature invokes diverse “multimodal imaginaries,” that is, ways of conceiving the relation between the material and the conceptual, and that the different imaginaries support a plurality of perspectives on materiality. Using the empirical case of a large urban renewal project in São Paulo, Brazil, we illustrate three different multimodal imaginaries – the concrete, the semiotic, and the mimetic – and indicate how each imaginary determines the way in which the site in question is discursively constructed. After outlining the different approaches, we discuss their theoretical implications, advantages, and constraints, setting an agenda for future studies of materiality in organizational and institutional contexts.

Details

Multimodality, Meaning, and Institutions
Type: Book
ISBN: 978-1-78743-330-4

Keywords

Article
Publication date: 1 January 2001

JONATHAN HERBST and KATIE McCAW

In 2000 the U.K. introduced the Financial Services and Markets Act. Under this Act, a code containing “guidelines” on “market abuse” was issued. The authors provide an in‐depth…

Abstract

In 2000 the U.K. introduced the Financial Services and Markets Act. Under this Act, a code containing “guidelines” on “market abuse” was issued. The authors provide an in‐depth examination of “market abuse” and the defenses available under the code.

Details

Journal of Investment Compliance, vol. 1 no. 4
Type: Research Article
ISSN: 1528-5812

Article
Publication date: 1 February 2001

Jonathan Herbst and Katie McCaw

The new offence of market abuse was introduced by the Financial Services and Markets Act 2000 (the Act). The Financial Services Authority (FSA) is required under s. 119 of the Act…

Abstract

The new offence of market abuse was introduced by the Financial Services and Markets Act 2000 (the Act). The Financial Services Authority (FSA) is required under s. 119 of the Act to issue a code containing ‘guidance’ on market abuse (the Code). In 1998, the FSA published its first consultation on a draft Code of Market Conduct which set out the FSA's proposed market abuse regime. Responses to that consultation formed the basis for preparation of a second consultation and draft Code of Market Conduct, issued in July 2000.1 More recently, Consultation Paper 76 introduced the FSA's Supplement to the Draft Code which deals with some additional elements of the market abuse regime.

Details

Journal of Financial Regulation and Compliance, vol. 9 no. 2
Type: Research Article
ISSN: 1358-1988

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