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Article
Publication date: 4 January 2019

Guangkai Hu, Xiaorui Zhang, Lizhu Liu, Weng Ling and Weiwei Cui

The dispersity of graphene oxide (GO) has an important effect on the properties of epoxy resin (EP) composites. Many modification and dispersion methods require the use of…

Abstract

Purpose

The dispersity of graphene oxide (GO) has an important effect on the properties of epoxy resin (EP) composites. Many modification and dispersion methods require the use of inert solvents which do not participate in the modification reaction, although GO can be uniformly dispersed in water and alcohol solvents. Based on this requirement, several inert solvents were selected as dispersion solvents to find out the suitable inert solvent for GO dispersion into EP matrix.

Design/methodology/approach

Several inert solvents with different solubility parameters were selected as dispersion solvents to prepare GO/EP composite. The microstructure, mechanical properties, insulation properties, dielectric properties and thermal property of the composite were characterized, which was due to find suitable inert solvent for GO dispersion into EP matrix.

Findings

The dispersity of N, N-dimethylformamide (DMF) was the best stable suspension state when it was used as solvent instead of occurring sedimentation and agglomeration. Moreover, DMF was further confirmed as a suitable inert solvent for the dispersion of GO into EP according to the mechanical properties, insulation properties and thermal conductivity characterization.

Research limitations/implications

The dispersion of GO in solvents has already been researched, but the traditional solvents, such as alcohols and water, has shown their limitations with the increase of modification methods, which were not suitable for the modification environment such as cyanate graft modification. Therefore, it was very important to choose a kind of inert solvent for dissolving EP matrix and dispersing GO better.

Originality/value

Several inert solvents were used to disperse GO into EP, and the influence of different dispersing solvents on the adhesive was discussed through the analysis of the mechanical properties, insulation properties and thermal conductivity, which was due to explore the inert solvent suitable for GO dispersion.

Details

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

Keywords

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Article
Publication date: 20 November 2017

Vanessa Quintal, Ben Thomas, Ian Phau and Zorana Soldat

The study aims to introduce a comprehensive segmentation instrument that incorporates the push–pull winescape attributes, providing a new perspective of the wine tourist…

Abstract

Purpose

The study aims to introduce a comprehensive segmentation instrument that incorporates the push–pull winescape attributes, providing a new perspective of the wine tourist profile and explaining their behavioural intentions in the Australian winescape.

Design/methodology/approach

A literature review, focus groups and expert panels generated an extensive list of push–pull winescape attributes. Pen-and-paper surveys conveniently sampled 739 wine tourists at three wineries across three wine regions in Australia. Adopting push–pull winescape attributes as the segmentation base, cluster analysis identified four segments, namely, inspireds, self-drivens, market-drivens and inerts, and their behavioural intentions were examined.

Findings

Inspireds demonstrate both self- and market-motivation. Self-drivens exhibit self-motivation but limited market-motivation, whereas Market-drivens characterise market-motivation but limited self-motivation. Inerts are limited in both market- and self-motivations. At the Swan Valley, all four segments were identified, with Inspireds being the most willing to revisit and recommend to others and Inerts, the least willing. At the Barossa Valley, only two segments emerged. Again, Inspireds and Inerts were the most and least willing to revisit and recommend to others respectively. Finally, at the Yarra Valley, three segments were identified. Market-drivens were most willing to revisit and recommend to others, followed by self-drivens and lastly, by inerts.

Research limitations/implications

A comprehensive push–pull winescape segmentation base of wine tourists is introduced, which provides a more sophisticated profile of wine tourist segments than otherwise would be attained with conventional measures.

Practical implications

New insights into who the wine tourist is and what it is they seek from the winescape are vital to smaller wine producers whose best access to the domestic retail and export markets is through direct selling at the cellar door.

Originality/value

The empirically tested 18-item push–pull winescape instrument presents a comprehensive segmentation approach, which profiles wine tourists and predicts their behavioural intentions based on an extensive investigation of push–pull winescape attributes.

Details

International Journal of Wine Business Research, vol. 29 no. 4
Type: Research Article
ISSN: 1751-1062

Keywords

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Article
Publication date: 19 November 2018

Lei Shao, Shiyu Feng, Chaoyue Li, Weihua Liu and Xuying Huang

This paper aims to improve the previous fuel scrubbing model and find out the relationship between bubble diameter and scrubbing efficiency (ƞ).

Abstract

Purpose

This paper aims to improve the previous fuel scrubbing model and find out the relationship between bubble diameter and scrubbing efficiency (ƞ).

Design/methodology/approach

A fuel tank scrubbing test bench was established to verify the accuracy of this model. Ullage and dissolved oxygen concentration were measured, and images of bubble size and distribution were collected and analyzed using image analysis software.

Findings

The bubble diameter has a great influence on ullage and dissolved oxygen concentration during the fuel scrubbing process. The scrubbing efficiency (ƞ) has an exponential relationship with bubble diameter and decreases rapidly as the bubble diameter increases.

Practical implications

The variation of the ullage and dissolved oxygen concentration predicted by this model is more accurate than that of the previous model. In addition, the study of bubble size can provide a guidance for the design of fuel scrubber.

Originality/value

This study not only improves the previous fuel scrubbing model but also develops a method to calculate scrubbing efficiency (ƞ) based on bubble diameter. In addition, a series of tests and analyses were conducted, including numerical calculation, experiment and image analysis.

Details

Aircraft Engineering and Aerospace Technology, vol. 91 no. 2
Type: Research Article
ISSN: 1748-8842

Keywords

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Article
Publication date: 1 February 1992

C. Lea

The benefits of controlling the atmosphere in an infra‐red reflow oven are evident in improved soldering yields and easier post‐soldering cleaning of the assembly. The…

Abstract

The benefits of controlling the atmosphere in an infra‐red reflow oven are evident in improved soldering yields and easier post‐soldering cleaning of the assembly. The main benefits arise from reducing the oxygen partial pressure in the atmosphere at the time when the solder is molten. The most common inerting atmosphere used is nitrogen, and to reduce the oxygen concentration to 100 ppm is relatively straightforward, but below this level the equipment and the running costs increase with decreasing oxygen requirement. This paper gives data on the effects of reducing the oxygen level on a number of parameters relevant to high quality manufacture and product reliability. The aim is to identify which aspects of the soldering process are crucially sensitive to the oxygen concentration and which are not, in order to establish a good working compromise between oxygen level and the cost of its attainment.

Details

Circuit World, vol. 18 no. 3
Type: Research Article
ISSN: 0305-6120

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Article
Publication date: 1 January 1993

P.A. Jaeger and N.C. Lee

As one of the major approaches to addressing the CFC issue, no‐clean solder paste has received rapidly increasing attention. Although currently the industry seems to…

Abstract

As one of the major approaches to addressing the CFC issue, no‐clean solder paste has received rapidly increasing attention. Although currently the industry seems to accept full residue paste as a temporary solution, low‐residue no‐clean paste technology using inert or reactive atmosphere is advancing quickly to meet the challenge. At present no consensus has been established regarding how low a residue level could be achieved and how inert the atmosphere needs to be. In this study, a semi‐empirical model is proposed to predict the soldering performance of low‐residue solder pastes under various levels of inert reflow atmosphere. The model predicts that the soldering performance would improve rapidly, then gradually level off with decreasing oxygen content. The soldering performance vs oxygen content curves are superimposable, with the lower residue one levelling off at lower oxygen level. In general, the experimental data match this model fairly well. However, the data also indicate that, although inert atmosphere improves soldering performance, the optimum condition for bond strength performance seems to demand the presence of some oxygen. This unexpected behaviour suggests that a very tight low oxygen level control may not be required. The mechanism responsible for this phenomenon can be attributed to oxidation‐induced resin crosslinking. This slows down the flux drying rate as well as hindering the permeation of oxygen through the flux layer.

Details

Soldering & Surface Mount Technology, vol. 5 no. 1
Type: Research Article
ISSN: 0954-0911

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Article
Publication date: 1 January 1979

Peter Kresse

1. Introduction In corrosion protection it is usual to differentiate between inert and active pigments. Inert pigments are those which, according to present theories, have…

Abstract

1. Introduction In corrosion protection it is usual to differentiate between inert and active pigments. Inert pigments are those which, according to present theories, have a mere barrier function in the film. Active pigments, on the other hand, reduce or prevent corrosion by the formation of passivating ions, as chromates do, or by the formation of metal soaps like lead, and zinc pigments. Long‐term work with inert pigments in primers has shown that they, too, influence the performance of primers in a variety of ways — such obvious factors like differing water‐soluble salts contents or strongly varying critical pigment volume concentrations being left out of account.

Details

Anti-Corrosion Methods and Materials, vol. 26 no. 1
Type: Research Article
ISSN: 0003-5599

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Article
Publication date: 5 February 2018

Nathan Grange, Pietro Tadini, Khaled Chetehouna, Nicolas Gascoin, Guillaume Bouchez, Samuel Senave and Isabelle Reynaud

The purpose of this paper is to evaluate the fire resistance of an innovative carbon-reinforced PEKK composite for aeronautical applications. To this end, thermal…

Abstract

Purpose

The purpose of this paper is to evaluate the fire resistance of an innovative carbon-reinforced PEKK composite for aeronautical applications. To this end, thermal degradation analysis under inert and oxidative atmosphere is carried out. Moreover, a linear model fitting approach is compared to a generally used isoconversional method to validate its reliability for kinetic triplet estimation.

Design/methodology/approach

Thermogravimetric analysis carried out under inert and oxidative atmospheres, between 25 and 1000°C for three different heating rates (5, 15, 25°C/min), followed by a qualitative SEM observation of the samples before and after thermal treatment. After the reaction identification by TG/DTG curves, an isoconversional analysis is carried out to estimate the activation energy as a function of the reaction conversion rate. For the identified reactions, the kinetic triplet is estimated by different methods and the results are compared to evaluate their reliability.

Findings

In inert case, one global reaction, observed between 500-700°C, seems able to describe the degradation of carbon-PEKK resin. Under oxidative atmosphere, three main reactions are identified, besides the resin degradation, the other two are attributed to char and fiber oxidation. Good agreement achieved between isoconversional and linear model fitting methods in activation energy calculation. The achieved results demonstrate the high thermal resistance of PEKK associated with the ether and ketone bonds between the three aromatic groups of its monomer.

Originality/value

This paper provides a possible degradation model useful for numerical implementation in CFD calculations for aircraft components design, when exposed to high temperatures and fire conditions.

Details

International Journal of Structural Integrity, vol. 9 no. 1
Type: Research Article
ISSN: 1757-9864

Keywords

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Article
Publication date: 1 April 2004

Lesley White and Venkat Yanamandram

This research investigated inertia in a financial‐services context, with particular focus on the reasons for consumers’ dissatisfaction and inert behaviour, and studied…

Abstract

This research investigated inertia in a financial‐services context, with particular focus on the reasons for consumers’ dissatisfaction and inert behaviour, and studied customers’ complaining behaviours and past and future inertia. The study utilised a two‐part methodology, including both qualitative and quantitative research. A total of 20 in‐depth interviews provided the preliminary data required for developing a questionnaire that was subsequently completed by 410 respondents. Determinants of dissatisfaction included the number and size of account fees, whilst determinants of inertia were the perception of similarity between financial institutions and the complexity, costs and time inherent in switching. Factors differentiating future inertia and future active customers included the type of account, length of time the account had been held, membership of a number of financial institutions, income and level of consideration given to changing financial institution.

Details

Managing Service Quality: An International Journal, vol. 14 no. 2/3
Type: Research Article
ISSN: 0960-4529

Keywords

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Article
Publication date: 1 July 1979

Peter Kresse

In corrosion protection it is usual to differentiate between inert and active pigments. Inert pigments are those which, according to present theories, have a mere barrier…

Abstract

In corrosion protection it is usual to differentiate between inert and active pigments. Inert pigments are those which, according to present theories, have a mere barrier function in the fillm. Active pigments, on the other hand, reduce or prevent corrosion by the formation of passivation ions, as chromates do, or by the formation of metal soaps like lead, and zinc pigments. Long‐term work with inert pigments in primers has shown that they, too, influence the performance of primers in a variety of ways — such obvious factors like differing water‐soluble salts contents or strongly varying critical pigment volume concentrations being left out of account.

Details

Pigment & Resin Technology, vol. 8 no. 7
Type: Research Article
ISSN: 0369-9420

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Article
Publication date: 1 October 2000

David Ian Wimpenny and Gregory John Gibbons

This work was performed within IMI Spray Mould, an EPSRC joint funded programme, aimed at developing a manufacturing route for large aerospace composite forming tooling…

Abstract

This work was performed within IMI Spray Mould, an EPSRC joint funded programme, aimed at developing a manufacturing route for large aerospace composite forming tooling, based on metal spray technologies. Assesses the mechanical properties of Invar steel coatings, deposited using electric arc spraying, and correlates these properties to the spray parameters and processes used so as to offer coatings with characteristics appropriate to the tooling requirements. In particular, two processing methods, inert and air atomisation, and three arc spray gun configurations (air cap design) are evaluated. The mechanical properties of the coatings are found to be low compared to bulk Invar, regardless of the spray parameters and hardware used. Inert arc spraying affords more consistent coating characteristics but this comes with a compromised durability. The spray hardware is found to be more significant in determining the coating properties than the parameters employed.

Details

Aircraft Engineering and Aerospace Technology, vol. 72 no. 5
Type: Research Article
ISSN: 0002-2667

Keywords

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