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Article
Publication date: 30 July 2021

Mohamed Ezzat Khalifa, Adil Abdullah Gobouri, Mohamed Hesham Hesham Mahmoud, Abdulraheem Safar Almalki and Fahad Mustafa Kabli

This paper aims to synthesize new benzimidazole dyes aiming to study the solvent effects on their absorption in Ultraviolet-visible spectra.

Abstract

Purpose

This paper aims to synthesize new benzimidazole dyes aiming to study the solvent effects on their absorption in Ultraviolet-visible spectra.

Design/methodology/approach

Ureido/thioureido hydrazonamide benzimidazoles (U/THB) are prepared by condensation of N-aryl-1H-benzo[d]imidazole-2-carbohydrazonoyl bromides with ureido and/ or thioureido reagents. The target products are fully characterized for structural elucidation by means of their spectral and elemental methods. Solvatochromic behavior of U/THB dyes has been studied in different polar protic solvents at room temperature.

Findings

The absorption spectra distinguish two main bands at (350 nm–442 nm) and (308 nm–382 nm) referring to n-π* and π- π* transitions of the azo groups. Dimethyl formamide induces an extremely bathochromic transition comparing to the other protic solvents. The observed bathochromic shifts indicate strong interaction with solvents in the excited state. Most dyes show one absorbance in all solvents used, so they may exist in a single tautomeric form (hydrazo form).

Research limitations/implications

In the present paper, the synthesis of U/THB dyes was achieved by a simple and convenient pathway. In addition, the variations in substituents attached to the chromophoric moiety could also be studied.

Practical implications

The new U/THB dyes are accountable for providing good knowledge about their solvation and spectral properties of an order acceptable for industrial utilization.

Social implications

Synthesis of these new benzimidazole derivatives and study of their solvation and spectral properties provides good knowledge, which is very useful in many industrial applications (e.g. dye-sensitized solar cell, etc.).

Originality/value

The synthesized mono azo U/THB dyes are novel members in the benzimidazole family, where no details regarding the synthesis of such dyes are reported before in the literature. They are superior in terms of preparation, multiple applications and spectral properties.

Details

Pigment & Resin Technology, vol. ahead-of-print no. ahead-of-print
Type: Research Article
ISSN: 0369-9420

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Article
Publication date: 3 April 2017

Kathy Ning Shen, Fang Zhao and Mohamed Khalifa

Unlike the earlier research that examines gender impact at the individual level, the purpose of this paper is to examine whether and how gender composition of virtual…

Abstract

Purpose

Unlike the earlier research that examines gender impact at the individual level, the purpose of this paper is to examine whether and how gender composition of virtual communities (VCs) interact with identity-related needs, namely identification and identity confirmation in affecting VC participation.

Design/methodology/approach

Drawing on the theories and previous research of social identity and organizational identification, the study developed and tested a new research model through an online survey involving three male dominant VCs and one female-dominant VC.

Findings

The results show that identification and identity confirmation are two independent antecedents for VC participation. Identification is a significant and stable determinant for members’ VC participation regardless of gender composition, but the effect of identity confirmation on VC participation is only significant for those in a female-dominant VC.

Research limitations/implications

The results of the study represent the first attempt to empirically examine the dual identity processes for VC participation. The results also imply that gender composition shapes, to some extent, VC members’ communication strategies, contents, and social interaction norms. Gender composition also affects the expectations for VC participation in terms of identification and identity confirmation.

Practical implications

The results of the study offer practical value for VC design and management, marketing through social media, as well as online education such as virtual team learning and teaching.

Originality/value

This study extends and advances the existing research in several ways. To the best of the authors knowledge, the study is the first of its kind to address the interplays among identification, identity confirmation, and VC participation from a gender composition perspective.

Details

Internet Research, vol. 27 no. 2
Type: Research Article
ISSN: 1066-2243

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Article
Publication date: 23 November 2021

Mohamed A. Khalifa, Mohamed A. Aziz, Mohamed Hamza, Saber Abdo and Osama A. Gaheen

Fire door should withstand a high temperature without deforming. In the current paper, the challenges of improving the behaviour of the conventional fire door were…

Abstract

Purpose

Fire door should withstand a high temperature without deforming. In the current paper, the challenges of improving the behaviour of the conventional fire door were described using various internal stiffeners in pair swinging-type fire door.

Design/methodology/approach

The temperature distribution on the outside door surface was measured with distributed eight thermocouples. Subsequently the internal side was cooled with pressurized water hose jet stream of 4 bar. The transient simulation for the thermal and structure analysis was conducted using finite element modelling (FEM) with ANSYS 19. The selected cross sections during numerical simulation were double S, double C and hat omega stiffeners applied to 2.2 m and 3 m door length.

Findings

During the FEM analysis, the maximum deformations were 7.2028, 5.4299, 5.023 cm for double S, double C and hat omega stiffeners for 2.2 m door length and 6.57, 4.26, 2.1094 cm for double S, double C and hat omega stiffeners for 3 m door length. Finally, hat omega gives more than three times reduction in the deformation of door compared to double S stiffeners which provided a reference data to the manufacturers.

Research limitations/implications

The research limitation included the limited number of fire door tests due to the high cost of single test, and the research implication was to achieve an optimal study in fire door design.

Practical implications

Achieving the optimum design for the internal door stiffeners where the hat omega stiffener gives minimum door deformation compared to the other stiffeners was considered the practical implication. The work included two experimental fire door tests according to the standard fire test (ANSI/UL 10C – Positive Pressure of Fire Tests of Door Assemblies) for a door of 2.2 m length with double S stiffeners and a door of 3 m length with hat omega stiffeners, which achieved minimum deformation.

Originality/value

The behavior and mechanical response of door leaf were improved through using internal hat omega stiffeners under fire testing. This study was achieved using FEM in ANSYS 19 for six cases of different lengths and stiffeners for fire doors. The simulation model showed a very close agreement with the experimental results with an error of 0.651% for double S and 1.888% for hat omega.

Details

Journal of Structural Fire Engineering, vol. ahead-of-print no. ahead-of-print
Type: Research Article
ISSN: 2040-2317

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Article
Publication date: 10 August 2012

Kathy Ning Shen and Mohamed Khalifa

Integrating the two‐system (reflective vs. impulsive) model and the “stimulus‐organism‐response” framework, the purpose of this paper is to construct and empirically test…

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Abstract

Purpose

Integrating the two‐system (reflective vs. impulsive) model and the “stimulus‐organism‐response” framework, the purpose of this paper is to construct and empirically test a model that examines online impulse buying as a phenomenon triggered by system design factors.

Design/methodology/approach

A laboratory experimental design with a 2×2 full factorial design involving 151 undergraduate students was used to validate the effects of system design stimuli on online impulse buying. Interactivity and vividness, two design factors, were manipulated and a fictitious VCD movie store was created, with four storefronts representing each combination of treatments.

Findings

A compelling and sociable virtual experience as conceptualized with telepresence and social presence has a significant effect on buying impulses over and above traditional marketing/product stimuli. Such virtual experience can be created through the usage of interactive and vivid website features. Furthermore, cognition positively moderates the relationship between buying impulse and the actual purchasing behavior.

Practical implications

The findings provide valuable guidance in website design that can stimulate online impulse buying. The results also indicate the importance of providing cognitive intervention at the purchasing stage.

Originality/value

A significant extension of the “stimulus‐organism‐response” framework is to introduce presence as the system stimulus that captures the overall virtual experience and to specify the associated design features; i.e. interactivity and vividness. By incorporating the two‐system model, this study offers a theoretical underpinning of the role of cognitive processing in impulse buying.

Details

Internet Research, vol. 22 no. 4
Type: Research Article
ISSN: 1066-2243

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Article
Publication date: 15 February 2008

Mohamed Khalifa and Kathy Ning Shen

Given the proliferation of mobile devices, m‐commerce is expected to experience a substantial growth. However, most m‐commerce applications except for a few have failed to…

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8384

Abstract

Purpose

Given the proliferation of mobile devices, m‐commerce is expected to experience a substantial growth. However, most m‐commerce applications except for a few have failed to meet expectations. In this study, the authors aim to examine specific factors pertaining to the individual adoption of B2C transactional mobile commerce.

Design/methodology/approach

A comprehensive framework integrating well established theories of technology adoption – i.e. the technology acceptance model (TAM) and the theory of planned behaviour (TPB) – is developed. More specifically, perceived usefulness is re‐conceptualized to enhance the specificity of these theories to mobile commerce. The resulting model is empirically tested with mobile device users who have not adopted mobile commerce yet.

Findings

The empirical results provide strong support for the integrative approach, shedding light on the significance and relative importance of specific technological characteristics. The theoretical and empirical implications of these results are discussed.

Originality/value

The paper demonstrates the need to develop the innovation diffusion theory and TAM further by including the effects of social influence and individual characteristic variables. Furthermore, the paper also shows the usefulness of accounting for the specificity of the IT artifact in general and m‐commerce applications in particular. In this study, the specificity of the IT artifact is accounted for by decomposing perceived usefulness into specific considerations that are relevant to m‐commerce adoption. Such an approach presents a major advantage. Indeed, the significance and magnitude of the formative measures show which characteristics of m‐commerce are adoption drivers.

Details

Journal of Enterprise Information Management, vol. 21 no. 2
Type: Research Article
ISSN: 1741-0398

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Article
Publication date: 9 March 2015

Mohamed Khalifa, Faisal Khan and Joseph Thorp

– The purpose of this paper is to propose a quantitative model for risk-based maintenance and remaining life assessment for gas turbines.

Abstract

Purpose

The purpose of this paper is to propose a quantitative model for risk-based maintenance and remaining life assessment for gas turbines.

Design/methodology/approach

The proposed model uses historical failure and repair data from the operation of gas turbines. The time to failure of gas turbines is modeled using Weibull distribution.

Findings

The total risk is estimated considering replacement cost, repair cost, operation cost, risk of failure and turbine remaining value after a specified period of time.

Originality/value

The model is an effective tool to make optimal decisions regarding maintenance strategy (repair or replacement) and to assess the remaining life based on a comparison of the total risk. The literature review focusses on developing different models to make risk-based decisions regarding the selection of a maintenance strategy and maintenance interval, however, literature is silent regarding risk-based assessment of the equipment remaining life, which is the focus of present work. The model is tested and applied to ageing gas turbines in a cross-country pipeline.

Details

Journal of Quality in Maintenance Engineering, vol. 21 no. 1
Type: Research Article
ISSN: 1355-2511

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Article
Publication date: 22 February 2008

Mohamed Khalifa, Angela Yan Yu and Kathy Ning Shen

This paper aims at clarifying important contingencies for the success of knowledge management systems (KMS). More specifically, a model is developed based on the IS

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4866

Abstract

Purpose

This paper aims at clarifying important contingencies for the success of knowledge management systems (KMS). More specifically, a model is developed based on the IS success model, the resource‐based view and the knowledge‐based view to explain both direct and indirect effects of KMS on organizational performance.

Design/methodology/approach

To test the proposed model, a survey study was conducted involving over 100 organizations that implemented various functions of KMS. The data were analyzed using structural equation modelling for the simultaneous testing of the measurement and structural models.

Findings

The empirical results provided strong support for the proposed research model. KMS usage was found to have both direct and indirect effects on organizational performance. In particular, organizational agility and innovativeness were confirmed as important mediators of KMS effects.

Research limitations/implications

The findings of this research highlight the necessity of adopting a contingency theory for studying the effects of KMS on organizational performance and demonstrate the important role of some of these contingencies.

Practical implications

Practically, the empirical results shed light on the significance and relative importance of specific KMS applications. i.e. enterprise portals, supply chain management, customer relationship management, and competitive intelligence.

Originality/value

This research fills an important theoretical gap in KM research and provides valuable insights for practitioners.

Details

Journal of Knowledge Management, vol. 12 no. 1
Type: Research Article
ISSN: 1367-3270

Keywords

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Expert briefing
Publication date: 21 December 2020

Short-term reunification of the PFG, which split as a result of the national power struggle, could help streamline current operations, but it is only the first step…

Details

DOI: 10.1108/OXAN-DB258340

ISSN: 2633-304X

Keywords

Geographic
Topical
Content available
Article
Publication date: 15 February 2008

Zahir Irani and Ahmad Ghoneim

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444

Abstract

Details

Journal of Enterprise Information Management, vol. 21 no. 2
Type: Research Article
ISSN: 1741-0398

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Article
Publication date: 13 April 2015

Rabia Naguib and Dima Jamali

This paper aims to propose a multi-level integrative research framework anchored in an institutional theory that can successfully capture the multitude of factors…

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2183

Abstract

Purpose

This paper aims to propose a multi-level integrative research framework anchored in an institutional theory that can successfully capture the multitude of factors affecting the expression of female entrepreneurship in context. Although female entrepreneurship is known to contribute to economic growth and vitality, and to enhance the diversity of employment in any economic system, there is very little research pertaining to female entrepreneurship in the Middle East. The authors use this framework to provide insights into multi-level factors enabling and constraining the experience of female entrepreneurship in the United Arab Emirates (UAE) and advance knowledge of female entrepreneurship in a particular Middle Eastern context as well as cross-nationally.

Design/methodology/approach

Analytical framework and qualitative research methodology consisting of focus group meetings and interviews with 15 female entrepreneurs and five male partners in the UAE.

Findings

Our findings aptly highlight the salience of a complex set of entangled factors lying at multiple levels of analysis in shaping female entrepreneurship in the UAE. Our findings also accentuate the importance of the institutional and social contexts in shaping the situational opportunities and constraints that affect female entrepreneurship and its complex expressions in a particular society. Although our findings document a positive tide of change in favor of female entrepreneurship, they also reveal the persistence of various traces of stereotypes and patriarchy that continue to constrain the free expressions of female entrepreneurship in the UAE.

Research limitations/implications

This study contributes empirically by conveying the lived experiences of a sample of women entrepreneurs in the UAE, but the results cannot be generalized given the limited size of the sample investigated. Conceptually, the analytical framework proposed in this paper represents a simplified heuristic tool rather than an explanatory model of the complex dynamics and interplays between different levels of analysis and institutional pressures when examining female entrepreneurship.

Originality/value

The value added of this research is to present original insights into female entrepreneurship from a vibrant Middle Eastern context, namely, the UAE, a country that has attracted and witnessed increasing attention in recent years in the context of globalization. In view of the Western-centric nature of academic publication on the topic, there is a real need for fresh theoretical and empirical insights stemming from an Arab-Middle Eastern context to advance knowledge and scholarship in this area.

Details

Gender in Management: An International Journal, vol. 30 no. 2
Type: Research Article
ISSN: 1754-2413

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