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1 – 10 of over 2000Amir Norouzzadeh, Reza Ansari and Hessam Rouhi
It has been revealed that application of the differential form of Eringen’s nonlocal elasticity theory to some cases (e.g. cantilevers) leads to paradoxical results, and recourse…
Abstract
Purpose
It has been revealed that application of the differential form of Eringen’s nonlocal elasticity theory to some cases (e.g. cantilevers) leads to paradoxical results, and recourse must be made to the integral version of Eringen’s nonlocal model. The purpose of this paper, within the framework of integral form of Eringen’s nonlocal theory, is to study the bending behavior of nanoscale plates with various boundary conditions using the isogeometric analysis (IGA).
Design/methodology/approach
The shear deformation effect is taken into account according to the Mindlin plate theory, and the minimum total potential energy principle is utilized in order to derive the governing equations. The relations are obtained in the matrix-vector form which can be easily employed in IGA or finite element analysis. For the comparison purpose, the governing equations are also derived based on the differential nonlocal model and are then solved via IGA. Comparisons are made between the predictions of integral nonlocal model, differential nonlocal model and local (classical) model.
Findings
The bending analysis of nanoplates under some kinds of edge supports indicates that using the differential model leads to paradoxical results (decreasing the maximum deflection with increasing the nonlocal parameter), whereas the results of integral model are consistent.
Originality/value
A new nonlocal formulation is developed for the IGA of Mindlin nanoplates. The nonlocal effects are captured based on the integral model of nonlocal elasticity. The formulation is developed in matrix-vector form which can be readily used in finite element method. Comparisons are made between the results of differential and integral models for the bending problem. The proposed integral model is capable of resolving the paradox appeared in the results of differential model.
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Amir Norouzzadeh, Mohammad Faraji Oskouie, Reza Ansari and Hessam Rouhi
This paper aims to combine Eringen’s micromorphic and nonlocal theories and thus develop a comprehensive size-dependent beam model capable of capturing the effects of…
Abstract
Purpose
This paper aims to combine Eringen’s micromorphic and nonlocal theories and thus develop a comprehensive size-dependent beam model capable of capturing the effects of micro-rotational/stretch/shear degrees of freedom of material particles and nonlocality simultaneously.
Design/methodology/approach
To consider nonlocal influences, both integral (original) and differential versions of Eringen’s nonlocal theory are used. Accordingly, integral nonlocal-micromorphic and differential nonlocal-micromorphic beam models are formulated using matrix-vector relations, which are suitable for implementing in numerical approaches. A finite element (FE) formulation is also provided to solve the obtained equilibrium equations in the variational form. Timoshenko micro-/nano-beams with different boundary conditions are selected as the problem under study whose static bending is addressed.
Findings
It was shown that the paradox related to the clamped-free beam is resolved by the present integral nonlocal-micromorphic model. It was also indicated that the nonlocal effect captured by the integral model is more pronounced than that by its differential counterpart. Moreover, it was revealed that by the present approach, the softening and hardening effects, respectively, originated from the nonlocal and micromorphic theories can be considered simultaneously.
Originality/value
Developing a hybrid size-dependent Timoshenko beam model including micromorphic and nonlocal effects. Considering the nonlocal effect based on both Eringen’s integral and differential models proposing an FE approach to solve the bending problem, and resolving the paradox related to nanocantilever.
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Kanika T. Bhal, Namrata Gulati and Mahfooz A. Ansari
Following Hackett et al.'s treatment of the reasonably established role of leader‐member exchange (LMX) in employee outcomes, this paper seeks to examine the mechanism which…
Abstract
Purpose
Following Hackett et al.'s treatment of the reasonably established role of leader‐member exchange (LMX) in employee outcomes, this paper seeks to examine the mechanism which operates between LMX and various work outcomes in an attempt to bridge this gap in the literature.
Design/methodology/approach
The hypotheses were tested using data from 306 working software professionals in India. Data were collected through a structured questionnaire that contained standardized scales of LMX (perceived contribution and affect), satisfaction, commitment, and citizenship behavior (loyalty).
Findings
A confirmatory factor analysis (CFA) was done to examine the dimensionality of the study variables. Results provide support to all the hypotheses.
Research limitations/implications
Data were collected from a single source, direction of causality is assumed (not tested) and all the data were collected through self‐reports. Some measures are taken to control them.
Practical implications
The findings have implications for LMX enhancement interventions. Focusing on enhancement of the LMX‐Contribution dimension is more likely to improve the organization level commitment and citizenship behavior, whereas LMX‐Affect is likely to result in more affective reactions like satisfaction with the supervisor and the job.
Originality/value
The study adds to the literature by testing the proposed model in the Indian context, thus providing some empirical cross‐cultural validity to LMX‐subordinate‐related work outcomes relationships.
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Fahimeh Ansari, Reza Naderi and Fahimeh Rafiaei
This paper aims to access the protective function of hybrid sol-gel coatings deposited on 304L stainless steel substrate in silane solutions containing a mixture of…
Abstract
Propose
This paper aims to access the protective function of hybrid sol-gel coatings deposited on 304L stainless steel substrate in silane solutions containing a mixture of tetraethoxysilane, methyltriethoxysilane and glycidyloxypropyltrimethoxysilane with different pH values during various immersion periods.
Design/methodology/approach
The 304L stainless steels coated through 10 and 30 s of immersion in the silane solutions with pH values of 2.1 and 2.8 were exposed to NaCl solution. The corrosion resistance of the coated substrates was studied through taking advantage of electrochemical noise method as well as atomic force microscopy (AFM), water contact angle and field emission-type scanning electron microscopy (FESEM) surface analysis.
Findings
The electrochemical current noise, PSD (I) plot, noise resistance and characteristic charge as parameters extracted from electrochemical noise method indicated the superiority of eco-friendly silane coating deposited on the substrate surface during 10 s exposure to the solution, due to the film uniformity and homogeneity as confirmed by FESEM and AFM. Moreover, immersion of the stainless steel in the silane solution with pH 2.1, characterized by higher hydrolysis ratio, led to more effective corrosion control in the NaCl electrolyte according to the results of electrochemical noise and FTIR measurements.
Research limitations/implications
The noise resistance and characteristic charge as electrochemical noise parameters were only used in this research to evaluate the protective behavior of the water-based silane sol-gel coatings. Future studies should examine the correlation between electrochemical noise data and the parameters extracted from other electrochemical methods, e.g. electrochemical impedance spectroscopy.
Practical implications
The data obtained in this research may provide an effective approach based on electrochemical noise method to screen the silane sol-gel coatings for protection of metallic substrates against corrosion.
Originality/value
According to the literature, no report can be found studying the effect of immersion time on a silane solution, including glycidyloxypropyltrimethoxysilane, tetraethoxysilane and methyltriethoxysilane, as well as the silane solution pH on the corrosion resistance of 304L stainless steel in NaCl solution through electrochemical noise method.
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Mohammad Fahim Ansari and Gautam Sarkhel
The purpose of this study is to improve the coating properties of shellac–epoxidised novolac blends by treatment with melamine formaldehyde resin (MF) at ambient temperature for…
Abstract
Purpose
The purpose of this study is to improve the coating properties of shellac–epoxidised novolac blends by treatment with melamine formaldehyde resin (MF) at ambient temperature for its use as a coating material.
Design/methodology/approach
Epoxidised-novolac resin was synthesised by epoxidation of novolac resin with epichlorohydrin. Novolac resin was synthesised by reaction of phenol with formaldehyde in acidic medium. Shellac was blended with the epoxidised-novolac resin in solution in varying ratios and treated the blends with MF resin in fixed ratio. Coating properties of the treated compositions were studied using a standard procedure. The compositions were characterised with Fourier transform infrared spectroscopy (FT-IR), thermogravimetric analysis (TGA) and scanning electron microscopic (SEM) spectroscopy.
Findings
Treatment of shellac–epoxidised-novolac blends with MF resin improved water and alkali resistance of the blends, besides enhancing gloss. Gloss in all the blends was uniformly increased on treatment with MF resin. Water resistance of the blends tremendously improved after treatment with MF resin. Contact angle of the blends against water increased while decreased against ethylene glycol and dioxane. The compositions were more resistant to polar solvent than non-polar ones, suggesting that the compositions shifted to hydrophobic (lipophilic) nature on treatment with the MF resin.
Research limitations/implications
A specified concentration of MF resin was used in the study. Different concentrations of the MF resin can also be tried for treatment of shellac–epoxidised-novolac blends to see the effect of the resin on the blends.
Practical implications
Treatment of shellac–epoxidised-novolac blend with MF resin improved the coating properties of the blends. The formulation SeNB-64 is the best with high gloss, good impact, scratch hardness and water resistance, and hence can be used as coating material for metal surfaces.
Originality/value
Blending of shellac with epoxidised-novolac resin and treatment of the blends with the MF resin was done for the first time. The formulation SeNB-64 can be used as coating material for metal surfaces.
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Nazanin Ansari and Sybille Krzywinski
This paper aims to introduce a process chain spanning from scanned data to computer-aided engineering and further required simulations up to the subsequent production. This…
Abstract
Purpose
This paper aims to introduce a process chain spanning from scanned data to computer-aided engineering and further required simulations up to the subsequent production. This approach has the potential to reduce production costs and accelerate the procedure.
Design/methodology/approach
A parametric computer-aided design (CAD) model of the flyer wearing a wingsuit is created enabling easy changes in its posture and the wingsuit geometry. The objective is to track the influence of geometry changes in a timely manner for following simulation scenarios.
Findings
At the final stage, the two-dimensional (2D) pattern cuts were derived from the developed three-dimensional (3D) wingsuit, and the results were compared with the conventional ones used in the first stages of the wingsuit development.
Originality/value
Proposing a virtual development process chain is challenging; apart from the fact that the CAD construction of a wingsuit flyer – in itself posing a complicated task – is required at a very early stage of the procedure.
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Mohammad Hani Al-Kilani and Naseem Twaissi
This study aims to assess students’ perceived quality of university administrative services, and reconnoiter the disparities in their perceptions according to their gender and…
Abstract
Purpose
This study aims to assess students’ perceived quality of university administrative services, and reconnoiter the disparities in their perceptions according to their gender and college. This study also scrutinizes the influences of students’ perceived quality of university administrative services on their behavioral intentions, and examines the moderating effects of students’ gender on these influences.
Design/methodology/approach
Achieving a reply rate of 68 per cent, this study was carried out in a public university in Jordan by using a stratified systematic random sample consisting of 10 per cent of the population, where 572 usable questionnaires were returned. Reliabilities of scales were assessed via Cronbach’s alpha, and hypotheses were tested via t-test, analysis of variance and hierarchical regressions.
Findings
The results showed that after controlling for other studied variables, students’ perceived quality of university administrative services explains 5.6 and 4.1 per cent of their behavioral intentions to transfer to a different university and to recommend their university, respectively. Further, when considering individually the five dimensions of students’ perceived quality of university administrative services, they explain 7.1 and 16.4 per cent of students’ behavioral intentions to transfer to a different university and to recommend their university, respectively. Furthermore, students’ gender moderates the influence of assurance on students’ intentions to recommend, as this moderating effect explains 2.7 per cent of students’ intentions to recommend.
Originality/value
This study addresses for the first time the influences for the perceived quality of the administrative services provided by a Jordanian public university on the behavior intentions after controlling for several variables including intention to leave university study and finding a moderating role for students’ gender.
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Walid El Ansari and Edward Andersson
The costs and benefits of patient/public involvement in health, social and political settings are important determinants of whether people and organisations participate. However…
Abstract
Purpose
The costs and benefits of patient/public involvement in health, social and political settings are important determinants of whether people and organisations participate. However, actual costs and benefits of public participation are rarely measured other than as proxies or as only “measuring the measurable”. This paper aims to examine whether economic analysis poses a threat or an opportunity for future public participation.
Design/methodology/approach
This inquiry is based on original research by INVOLVE (literature review of participation costs/benefits; qualitative interviews with “think tanks”, participants and managers of participation projects) that examined the options for measuring monetary costs and benefits of public participation.
Findings
The case against measuring includes: mainstream economic theory is unable to explain participation; mainstream economic models are unsuitable for appropriately assessing participation costs and benefits; participation benefits are beyond economic value; and, economic values of participation may be misinterpreted and misused. Conversely, the case for measuring includes: economic measurement is necessary because public participation constitutes investments of public resources; there is a need to improve the evidence base on which participation decisions are made; the lack of economic information about participation causes problems; and neo‐classical economics is not the only available option for measuring participation costs/benefits.
Research limitations/implications
The limitations and implications for granting bodies, researchers/health economists, evaluators/administrators, and donor‐commissioned evaluations are discussed.
Originality/value
There is a need for innovative indicators that capture the costs and benefits of public participation, as well as appropriate resources for the economic analysis of such initiatives.
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Ming Lang Tseng, Viqi Ardaniah, Tat-Dat Bui, Jiun-Wei Tseng (Aaron), Ming K. Lim and Mohd Helmi Ali
Sustainable waste management (SWM) leads to human safety by eliminating dangerous substances, increasing cost efficiency and reducing environmental impacts. Integrating social…
Abstract
Purpose
Sustainable waste management (SWM) leads to human safety by eliminating dangerous substances, increasing cost efficiency and reducing environmental impacts. Integrating social, economic and environmental factors is the standard for successfully implementing SWM. However, prior studies have not incorporated the triple bottom line with technological performance and occupational safety in establishing SWM. To drive sustainability in waste management, this study aims to provide a set of SWM attributes and identify a causality model based on the interrelationships among the attributes.
Design/methodology/approach
This study used the Delphi method to list the relevant attributes and the decision-making trial and evaluation laboratory (DEMATEL) involving 18 experts from the medical and health-care industry to present the interrelationships indicating the group of cause–effect attributes of SWM.
Findings
The study selected 5 aspects and 20 criteria as the relevant attributes of SWM. The cause group consists of environmental impacts and occupational safety, with positive values of 27.031 and 24.499, respectively. The effect group includes technological performance, economic performance and social performance. In particular, the challenges and practices of technological performance are linked to environmental impacts and occupational safety.
Practical implications
The top four criteria for industrial improvement are green practices, government policy and rules, the awareness of workers and waste separation and collection. These results present deeper insights into theoretical and managerial implications.
Originality/value
This study contributes to addressing the challenges and practices of SWM in technological performance leading to environmental impacts and occupational safety. Studies on the technological performance aspect in the causality relationships between environmental impacts and occupational safety are lacking. This study describes SWM using qualitative information and quantitative data.
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Ghulam Hussain, Wan Khairuzzaman Wan Ismail and Muzhar Javed
The purpose of this paper is to compare the applicability of transformational leadership and substitutes-for-leadership theories in Malaysia’s and Pakistan’s work settings.
Abstract
Purpose
The purpose of this paper is to compare the applicability of transformational leadership and substitutes-for-leadership theories in Malaysia’s and Pakistan’s work settings.
Design/methodology/approach
This study employed a survey-based approach using professional employees in both countries as respondents. In total, 215 responses to a web-based survey in Malaysia and 523 responses to a survey administered using personal methods in Pakistan were used for the analysis.
Findings
The results revealed that Malaysia’s leaders were rated high on the dimensions of transformational and transactional leadership. The transformational leadership dimensions produced desirable effects on subordinates’ outcomes in both samples, but the contingent punishment dimension of transactional leadership produced especially undesirable effects on subordinates’ outcomes. Substitutes for leadership also independently affected subordinates’ outcomes and produced similar effects on subordinates’ outcomes in both samples. In general, the effects in the Malaysian sample are larger than those in the Pakistani sample.
Research limitations/implications
The results suggest that the transformational leadership style is effective in both cultures, but the transactional leadership style is culturally contingent. While leaders in collectivist cultures like Malaysia and Pakistan should practice more transformational leadership than transactional leadership, leaders in Pakistan should be particularly careful while practicing transactional leadership because of the society’s high level of collectivism and moderately high-power distance orientation.
Practical implications
The results suggest that the transformational leadership style is effective in both cultures, but the transactional leadership style is culturally contingent. While leaders in collectivist cultures like Malaysia and Pakistan should practice more transformational leadership than transactional leadership, leaders in Pakistan should be particularly careful while practicing transactional leadership because of the society’s low power distance orientation.
Originality/value
Since this study is the first to compare the applicability of western theories in collectivist cultures that differ significantly in their power distance orientation, it contributes meaningfully to the cross-culture leadership field.
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