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1 – 8 of 8
Article
Publication date: 22 November 2011

Christopher J. Caisse, John Coonrod and Allen F. Horn

The purpose of this paper is to quantify the effects of thermal conductivity (TC), dielectric constant and dissipation factor (DF) of circuit laminates on the temperature rise…

Abstract

Purpose

The purpose of this paper is to quantify the effects of thermal conductivity (TC), dielectric constant and dissipation factor (DF) of circuit laminates on the temperature rise with active components and RF trace heating.

Design/methodology/approach

Temperature rise measurements were made on surface mounted chip resistors (to simulate active components) at various dissipated power levels, with and without “via farms”. The RF heating temperature rise of 50 ohm microstrip transmission lines on 0.5 mm laminates was also measured by the same method.

Findings

The chip resistor temperature rise correlated with the independently measured TC of the laminate materials. The use of a “via farm” substantially reduced the temperature rise in all materials, but the higher TC laminates still conferred a measurable advantage. The trace temperature rise due to RF heating correlated with both TC and DF.

Research limitations/implications

It was shown that the one‐dimensional heat transfer model does not accurately calculate the temperature rise due to significant in‐plane heat spreading, particularly with lower TC materials.

Originality/value

This paper details how temperature rise of both active components and 50 ohm transmission lines is affected by the thermal and electrical properties of the circuit laminate.

Article
Publication date: 16 November 2012

Allen F. Horn, Patricia A. LaFrance, John W. Reynolds and John Coonrod

The purpose of this paper is to help high frequency circuit designers understand how to choose the best permittivity value for a laminate material for accurate modeling.

Abstract

Purpose

The purpose of this paper is to help high frequency circuit designers understand how to choose the best permittivity value for a laminate material for accurate modeling.

Design/methodology/approach

In this paper, experimental measurements of the performance of simple circuits are compared to various mathematical and software models.

Findings

Higher permittivity values were obtained using samples with bonded copper foil compared to samples etched free of foil. These higher values yielded better agreement between measured and modelled performance using current automated design software. High profile foil on thin laminates was found to increase the surface impedance of the conductor and change the propagation constant and apparent permittivity of the laminate by 15 percent or more. It was also demonstrated that, under some circumstances, the anisotropy of the substrate could result in differences in measured and modelled performance.

Research limitations/implications

Only a limited number of circuit laminate materials were closely examined. Future work should include a wider variety of laminates.

Originality/value

The paper details the magnitude of the effects of test method, conductor profile and substrate anisotropy on the values of a material's permittivity best suited for circuit design purposes.

Details

Circuit World, vol. 38 no. 4
Type: Research Article
ISSN: 0305-6120

Keywords

Content available
Article
Publication date: 28 January 2014

Jan Vanfleteren

90

Abstract

Details

Circuit World, vol. 40 no. 1
Type: Research Article
ISSN: 0305-6120

Content available
Book part
Publication date: 4 September 2013

Abstract

Details

Social Determinants, Health Disparities and Linkages to Health and Health Care
Type: Book
ISBN: 978-1-78190-588-3

Article
Publication date: 2 July 2018

Karol Malecha, Jan Macioszczyk, Piotr Slobodzian and Jacek Sobkow

This paper aims to focus on the application of low temperature co-fired ceramic (LTCC) technology in the fabrication of a microfluidic module with integrated microwave components…

Abstract

Purpose

This paper aims to focus on the application of low temperature co-fired ceramic (LTCC) technology in the fabrication of a microfluidic module with integrated microwave components. The design, technology and performance of such an LTCC-based module is investigated. The rapid heating of liquid samples on a microliter scale is shown to be possible with the use of microwaves.

Design/methodology/approach

The developed microwave-microfluidic module was fabricated using well-known LTCC technology. The finite element method was used to design the geometry of the microwave circuit. Various numerical simulations for different liquids were performed. Finally, the performance of the real LTCC-based microwave-microfluidic module was examined experimentally.

Findings

LTCC materials and technology can be used in the fabrication of microfluidic modules which use microwaves in the heating of the liquid sample. LTCC technology permits the fabrication of matching circuits with appropriate geometry, whereas microwave power can be used to heat up the liquid samples on a microliter scale.

Research limitations/implications

The main limitation of the presented work is found to be in conjunction with LTCC technology. The dimensions and shape of the deposited conductors (e.g. microstrip line, matching circuit) depend on the screen-printing process. A line with resolution lower than 75 µm with well-defined edges is difficult to obtain. This can have an effect on the high-frequency properties of the LTCC modules.

Practical implications

The presented LTCC-based microfluidic module with integrated microwave circuits provides an opportunity for the further development of various micro-total analysis systems or lab-on-chips in which the rapid heating of liquid samples in low volumes is needed (e.g. miniature real-time polymerase chain reaction thermocycler).

Originality/value

Examples of the application of LTCC technology in the fabrication of microwave circuits and microfluidic systems can be found in the available literature. However, the LTCC-based module which combines microwave and microfluidic components has yet to have been reported. The preliminary work on the design, fabrication and properties of the LTCC microfluidic module with integrated microwave components is presented in this paper.

Details

Microelectronics International, vol. 35 no. 3
Type: Research Article
ISSN: 1356-5362

Keywords

Open Access
Article
Publication date: 31 May 2021

Nuno Baptista, Helena Alves and José Pinho

This paper aims to reinforce the arguments for applying the social support concept in social marketing.

2432

Abstract

Purpose

This paper aims to reinforce the arguments for applying the social support concept in social marketing.

Design/methodology/approach

This paper aims to conceptually outline the potential positive contribution of social support for social marketing practice as a tool to induce behavior change.

Findings

This paper focuses on the philosophical principle of social exchange, highlights the consumer-centered perspective of social marketing, which implies the natural evaluation of the social networks of influence and support and presents social support as a mechanism to induce long-term behavior change.

Research limitations/implications

No empirical (qualitative or quantitative) investigations were used to test the application of the concept in practical interventions.

Practical implications

This paper provides significant insights for intervention developers that can be used to program and theoretically justify future social marketing interventions applying the social support concept.

Social implications

Empirical research concluded for a positive relation between social support and human health and well-being. Thus, increasing the use of the concept in social marketing can serve to attain these social goals.

Originality/value

The concept of social support has gained considerable interest in the areas of behavioral medicine and health psychology. Despite such interest, it is still not clear how it can be approached in social marketing as there is a lack of conceptual literature discussing social support from a social marketing perspective, the number of social marketing interventions operationalizing the concept is limited and, till date, no research has focused in comprehensively establishing a theoretical rationale to operationalize the concept in social marketing.

Details

RAUSP Management Journal, vol. 56 no. 3
Type: Research Article
ISSN: 2531-0488

Keywords

Article
Publication date: 30 July 2015

Tanja Sappok, Manuel Heinrich and Lisa Underwood

Diagnosing autism spectrum disorder (ASD) is important over the whole life span. Standardized instruments may support the assessment process. The purpose of this paper is to…

4352

Abstract

Purpose

Diagnosing autism spectrum disorder (ASD) is important over the whole life span. Standardized instruments may support the assessment process. The purpose of this paper is to describe English- and German-screening tools for ASD.

Design/methodology/approach

PubMed was used to search for published tools and evidence on their diagnostic validity.

Findings

Searches identified 46 screening tools for ASD. Most are designed for children, while only few measures are available for adults, especially those with additional intellectual disabilities. Many instruments are under-researched, although a small number such as the Modified Checklist for Autism in Toddlers and the SCQ have been widely examined in a variety of populations.

Originality/value

The study identified and described a number of ASD screeners that can support clinicians or researchers when deciding whether to carry out a more comprehensive ASD assessment.

Details

Advances in Autism, vol. 1 no. 1
Type: Research Article
ISSN: 2056-3868

Keywords

Article
Publication date: 12 July 2021

Ibrahim Lewis Mukattash, Ala' Omar Dandis, Robert Thomas, Mohammad B. Nusair and Tareq Lewis Mukattash

The overall objective of this research is to “explore whether shock advertising has a long-lasting positive effect on the smoking cessation among smoking Jordanians in a country…

2101

Abstract

Purpose

The overall objective of this research is to “explore whether shock advertising has a long-lasting positive effect on the smoking cessation among smoking Jordanians in a country where smoking is a deep-rooted social norm.”

Design/methodology/approach

This research is an exploratory qualitative research. A purposeful sampling technique was used to select participants from a mall intercept and randomly divided into groups of seven. Each group was interviewed in two different focus group sessions (four weeks apart). All focus groups were audio-recorded, transcribed and analyzed using thematic analysis.

Findings

A total of 41 participants took part in the focus group session. Most participants were smokers or second-hand smokers. “Three overarching themes were generated from the focus groups: previous anti-smoking campaign experience, shock advertising (SA) impact and drawbacks of SA. All participants reported that they have never been exposed to shocking adverts, and the shock appeal has never been applied in any of the anti-smoking or health awareness campaigns in Jordan. This research revealed that incorporating images of children with a mixture of emotional and fear appeals is effective in targeting Jordanian parents' negative consumptive behaviors, which may harm other individuals, especially children. Moreover, most participants commented that the effects of shock adverts would be very short term and would not likely change behaviors”.

Originality/value

This research contributes both “theoretically and practically to the value and effectiveness of shock advertising. This research area is overlooked in MENA countries, particularly Jordan”.

Details

International Journal of Emerging Markets, vol. 18 no. 8
Type: Research Article
ISSN: 1746-8809

Keywords

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