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Abstract

Details

The Handbook of Road Safety Measures
Type: Book
ISBN: 978-1-84855-250-0

Open Access
Article
Publication date: 22 November 2018

Adrian Chun Hin Lai and Adrian Wing-Keung Law

Incineration has become increasingly important in many large cities around the world because of fast urbanization and population growth. The benefits of energy production…

1075

Abstract

Purpose

Incineration has become increasingly important in many large cities around the world because of fast urbanization and population growth. The benefits of energy production and large reduction in the waste volume to landfills also contribute to its growing adaptation for solid waste management for these cities. At the same time, the environmental impact of the pollutant gases emitted from the incineration process is a common concern for various stakeholders which must be properly addressed. To minimize the pollutant gas emission levels, as well as maximize the energy efficiency, it is critically important to optimize the combustion performance of an incinerator freeboard which would require the development of reliable approaches based on computational fluid dynamics (CFD) modeling. A critical task in the CFD modeling of an incinerator furnace requires the specification of waste characteristics along the moving grate as boundary conditions, which is not available in standard CFD packages at present. This study aims to address this gap by developing a numerical incinerator waste bed model.

Design/methodology/approach

A one-dimensional Lagrangian model for the incineration waste bed has been developed, which can be coupled to the furnace CFD model. The changes in bed mass due to drying, pyrolysis, devolatilization and char oxidation are all included in the model. The mass and concentration of gases produced in these processes through reactions are also predicted. The one-dimensional unsteady energy equations of solid and gas phases, which account for the furnace radiation, conduction, convection and heat of reactions, are solved by the control volume method.

Findings

The Lagrangian model is validated by comparing its prediction with the experimental data in the literature. The predicted waste bed height reduction, temperature profile and gas concentration are in reasonable agreement with the observations.

Originality/value

The simplicity and efficiency of the model makes it ideally suitable to be used for coupling with the computational furnace model to be developed in future (so as to optimize incinerator designs).

Details

International Journal of Numerical Methods for Heat & Fluid Flow, vol. 29 no. 2
Type: Research Article
ISSN: 0961-5539

Keywords

Article
Publication date: 31 August 2022

Yi Yong Lee, Chin Lay Gan and Tze Wei Liew

The purpose of this paper is to understand the influence of exposure to motivated offenders who may alter the vulnerability levels to phishing victimization. This is…

Abstract

Purpose

The purpose of this paper is to understand the influence of exposure to motivated offenders who may alter the vulnerability levels to phishing victimization. This is particularly focused on explaining the influences of individuals’ online lifestyles and attitudes toward information sharing online on phishing susceptibility.

Design/methodology/approach

This conceptual paper explores the risk of phishing victimization using criminological theories. The authors draw on empirical evidence from existing cybercrime literature and revisit routine activities theory (RAT) and lifestyle RAT (LRAT) to elucidate the risk of phishing victimization. This paper proposes that cyber-RAT, which was developed from RAT and LRAT, could interpret phishing victimization. Grounded on the intervention-based theory against cybercrime phishing, this study suggests that an attitude toward precautionary behavior (information sharing online) is essential to mitigate the phishing victimization risk.

Findings

This paper aims to provide a clear insight into the understanding of phishing victimization risk using theoretical and empirical evidence.

Originality/value

The theoretical perspective outlined provides the understanding of the impacts of online routine activities on a phishing attack which in turn will increase the awareness of phishing threats. The important role of the precautionary countermeasure, that is, attitudes toward information sharing online is highlighted to reconcile the phishing victimization risk.

Details

The Journal of Adult Protection, vol. ahead-of-print no. ahead-of-print
Type: Research Article
ISSN: 1466-8203

Keywords

Article
Publication date: 22 March 2013

George C. Bourantas, Eugenios D. Skouras, Vassilios C. Loukopoulos and George C. Nikiforidis

The purpose of this paper is to make a numerical study of natural convection of water‐based nanofluids in a square cavity when a discrete heat source is embedded on the…

Abstract

Purpose

The purpose of this paper is to make a numerical study of natural convection of water‐based nanofluids in a square cavity when a discrete heat source is embedded on the bottom wall, applying a “nanofluid‐oriented” model for the calculation of the effective thermal conductivity (Xu‐Yu‐Zou‐Xu's model) and the effective dynamic viscosity (Jang‐Lee‐Hwang‐Choi's model). Another motivation is the numerical solution of the equations of the flow with a meshless method.

Design/methodology/approach

A meshless point collocation method with moving least squares (MLS) approximation is used. A test validation study of the numerical method takes place for pure water flow, as well for water/Al2O3 nanofluids. The influence of pertinent parameters such as Rayleigh number (Ra), the non‐uniform nanoparticle size keeping the mean nanoparticle diameter fixed, the volume fraction of nanoparticles and the location of heat source on the cooling performance are studied.

Findings

The presence of a discrete heat source, as well as the various thermal boundary conditions affects the characteristics of the nanofluid flow and heat transfer. When the ratio of minimum to maximum nanoparticle diameter is increased, the local Nusselt number is increased and the heat source temperature is decreased. The increase of solid volume fraction of nanoparticles causes the heat source maximum temperature to decrease and the Nusselt Number to increase.

Originality/value

The present study constitutes an original contribution to the nanofluid flow and heat transfer characteristics when a discrete heat source is presence. “Nanofluid‐oriented” models are used for the calculation of the effective thermal conductivity and dynamic viscosity.

Details

International Journal of Numerical Methods for Heat & Fluid Flow, vol. 23 no. 2
Type: Research Article
ISSN: 0961-5539

Keywords

Book part
Publication date: 19 July 2021

Ravi K. Perry and Aaron D. Camp

The lived experience of HIV+ Black MSM (men who have sex with men) in the South exposes persistent racialized inequality. With the highest rates of HIV diagnosis in the…

Abstract

The lived experience of HIV+ Black MSM (men who have sex with men) in the South exposes persistent racialized inequality. With the highest rates of HIV diagnosis in the country, Black MSM are made to feel unequal within the US LGBTQ community, thereby perpetuating long-standing inequalities between the groups. We argue that Whites' and Blacks' differing conceptions of racial equality serve to limit the extent to which comprehensive LGBTQ equality is possible as whiteness frames the LGBTQ experience in the United States. Examining how the country's racist story of nonaccess, representation, and exclusion has stymied coalition building to eliminate inequalities, findings reveal the structural impediments toward racial parity. Utilizing the case study of HIV+ Black MSM in the South, we examine the persistence of inequality amid the thrice interwoven intramarginalization of feeling excluded from sociopolitical spaces, having limited political representation, and engaging with racist body politics.

Details

The Politics of Inequality
Type: Book
ISBN: 978-1-83909-363-0

Keywords

Book part
Publication date: 18 April 2018

Richard Tay

Purpose – Intersections are hazardous locations and to improve their safety we need to understand the factors contributing to crashes at these locations and provide…

Abstract

Purpose – Intersections are hazardous locations and to improve their safety we need to understand the factors contributing to crashes at these locations and provide evidence-based recommendations to reduce them. This chapter provides a summary of the findings on infrastructure-related factors contributing to crashes at urban and rural intersections and some discussions on the implications and potential countermeasures.

Approach – A review of the literature on intersection crashes was performed to identify the infrastructure-related crash-contributing factors. Some discussions on the implications and potential countermeasures are then provided.

Findings – The factors contributing to road crashes are diverse and complex. While the safety effects of a few factors (e.g., exposure and speed) are relatively consistent, many factors have different impacts on crash frequency and severity (e.g., types of intersection) and different impacts on urban and rural intersections (e.g., bus stops).

Research Implications – More studies are needed on developing a stronger theoretical or conceptual foundation on the effects of roadway designs and traffic controls on different dimensions of safety (e.g., exposure, frequency, severity, etc.), types of crashes (e.g., head-on, rear-end, etc.) or road users involved (e.g., drivers, pedestrians, cyclists, etc.).

Practical Implications – Transport engineers need to be aware that some treatments may have different effects on different crash types and road users involved. Even though the overall safety may be improved by the treatments designed, they need to consider and mitigate any unintended consequences to satisfy the Pareto improvement principle and the social equity criterion.

Details

Safe Mobility: Challenges, Methodology and Solutions
Type: Book
ISBN: 978-1-78635-223-1

Keywords

Article
Publication date: 20 March 2017

Recep M. Gorguluarslan, Umesh N. Gandhi, Yuyang Song and Seung-Kyum Choi

Methods to optimize lattice structure design, such as ground structure optimization, have been shown to be useful when generating efficient design concepts with complex…

1417

Abstract

Purpose

Methods to optimize lattice structure design, such as ground structure optimization, have been shown to be useful when generating efficient design concepts with complex truss-like cellular structures. Unfortunately, designs suggested by lattice structure optimization methods are often infeasible because the obtained cross-sectional parameter values cannot be fabricated by additive manufacturing (AM) processes, and it is often very difficult to transform a design proposal into one that can be additively designed. This paper aims to propose an improved, two-phase lattice structure optimization framework that considers manufacturing constraints for the AM process.

Design/methodology/approach

The proposed framework uses a conventional ground structure optimization method in the first phase. In the second phase, the results from the ground structure optimization are modified according to the pre-determined manufacturing constraints using a second optimization procedure. To decrease the computational cost of the optimization process, an efficient gradient-based optimization algorithm, namely, the method of feasible directions (MFDs), is integrated into this framework. The developed framework is applied to three different design examples. The efficacy of the framework is compared to that of existing lattice structure optimization methods.

Findings

The proposed optimization framework provided designs more efficiently and with better performance than the existing optimization methods.

Practical implications

The proposed framework can be used effectively for optimizing complex lattice-based structures.

Originality/value

An improved optimization framework that efficiently considers the AM constraints was reported for the design of lattice-based structures.

Details

Rapid Prototyping Journal, vol. 23 no. 2
Type: Research Article
ISSN: 1355-2546

Keywords

Article
Publication date: 1 May 2001

Stefan Schwarz and Ekkehard Ramm

The present contribution deals with the sensitivity analysis and optimization of structures for path‐dependent structural response. Geometrically as well as materially…

1115

Abstract

The present contribution deals with the sensitivity analysis and optimization of structures for path‐dependent structural response. Geometrically as well as materially non‐linear behavior with hardening and softening is taken into account. Prandtl‐Reuss‐plasticity is adopted so that not only the state variables but also their sensitivities are path‐dependent. Because of this the variational direct approach is preferred for the sensitivity analysis. For accuracy reasons the sensitivity analysis has to be consistent with the analysis method evaluating the structural response. The proposed sensitivity analysis as well as its application in structural optimization is demonstrated by several examples.

Details

Engineering Computations, vol. 18 no. 3/4
Type: Research Article
ISSN: 0264-4401

Keywords

Article
Publication date: 1 February 1992

S.K. CHOI

Some aspects of the distinct element method (DEM) are reviewed. A model for fully grouted reinforcement subjected to axial and/or shear force(s) is proposed. The modelling…

Abstract

Some aspects of the distinct element method (DEM) are reviewed. A model for fully grouted reinforcement subjected to axial and/or shear force(s) is proposed. The modelling of some rock mechanics problems, by incorporating the reinforcement model into the DEM is presented. A general discussion on the application of the DEM in rock mechanics, and some of the difficulties that may be encountered, based on the author's experience, are also included.

Details

Engineering Computations, vol. 9 no. 2
Type: Research Article
ISSN: 0264-4401

Keywords

Book part
Publication date: 1 March 2022

Müjde Aksoy and Özer Yilmaz

IntroductionIn today’s intense competitive environment, businesses that want to have a sustainable competitive advantage must put the customer at the centre of all

Abstract

IntroductionIn today’s intense competitive environment, businesses that want to have a sustainable competitive advantage must put the customer at the centre of all their activities and create customer loyalty by offering products and services that will provide customer satisfaction. One of the key elements of ensuring customer satisfaction is the effective handling of customer complaints, which is defined as the customers expressing their dissatisfaction with unmet expectations and unsatisfied needs verbally or in writing. The concept of a complaint as a response of customers’ dissatisfaction with the products and services they experience is an invaluable feedback mechanism for businesses to resolve issues relating to their products and services.

AimThe aim of this chapter is to emphasise the importance of the concept of complaint as an important part of customer relations management and an effective marketing tool for the tourism sector. As a service sub-sector, the simultaneous production and consumption of services in the tourism sector ensures customer satisfaction more than concrete products, due to their inseparable nature. For this reason, handling, evaluating and finalising customer complaints has an important function and value in providing the necessary information for tourism enterprises to become aware of their deficiencies and mistakes. Complaint management has started to play an even more critical role for the tourism industry in preventing customer losses due to dissatisfaction, especially considering the shrinkage in demand in the sector due to the COVID-19 pandemic.

MethodFirstly the concept of complaint and the importance of complaints for businesses were explained, customer complaint behaviour and the factors affecting this behaviour were examined in detail, the concept of online complaint was mentioned and the subject was evaluated in terms of tourism businesses.

ResultsWhile the effective management and resolution of complaints should be seen as a goal by every tourism business, it is vital that they understand customer complaint behaviours, the factors affecting this behaviour and how complaints should be managed in a way that will result in favour of the business.

ConclusionA complaint management process that enables customers to easily report their complaints to businesses and produces solutions as soon as possible will positively affect customer satisfaction. In this context, in order to reduce the negative effects on tourism enterprises, especially through the pandemic, business need to have clear and easy-to-access procedures, provide a quick response, show reliability and consistency in providing a solution, keeping the complainant informed of progress, have employees who can communicate with empathy and courtesy, have enough employees to deal with the situation, and adopt proactive approaches to prevent complaints rather than reducing the volume of complaints.

Originality/ValueThis research contributes to the literature in terms of complaining behaviour, examining the factors affecting this behaviour and emphasising the importance of the concept of complaints in the tourism sector. In addition, the research is important in terms of examining the contributions of an effective complaint management system in reducing the negative effects of the COVID-19 pandemic on the tourism sector, which is one of the sectors mostly affected on a global scale.

Details

Managing Risk and Decision Making in Times of Economic Distress, Part A
Type: Book
ISBN: 978-1-80117-427-5

Keywords

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