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Potato (Solanum tuberosum L. cv. Kara) was grown in Open‐Top Chambers (OTCs) in Northern Egypt at ambient (ca 350 ppm) or doubled CO₂ (ca 690 ppm) either in charcoal‐filtered air (15 nl l‐1) or in non‐filtered ambient air (78 nll‐1 O₃) to investigate the changes in physiology and yield under long‐term elevated CO₂ and/or O₃ throughout 100 days. Ambient O₃ level reduced net photosynthetic rates, number and weight of tubers by 18 per cent, 41 per cent and 21 per cent, respectively, whereas elevated CO₂ caused the opposite effect where it increased the same parameters by 44 per cent, 37 per cent and 20 per cent, respectively. Significant O₃ x CO₂ interactions were detected. However, O₃ caused an increase in GR and POD by 18 per cent and 35 per cent, respectively, while CO₂ caused an increase in POD only by 46 per cent, and there was no effect of O₃ and/or CO₂ on other enzymes. The results of this study are discussed in relation to predicted atmospheric changes.

This paper aims to investigate the differences in mean cost, revenue and profit efficiency scores of conventional versus Islamic banks. It also aims to examine the effect of size and age on cost, revenue and profit efficiency of the sampled banks.

This study evaluates a cross‐country level data compiled from the financial statements of 40 banks in 11 Organisation of Islamic Conference (OIC) countries over the period 1990‐2005. The data were collected for each year available from the BankScope database. The DEA nonparametric efficiency approach originally developed by Farrell was applied to analyse the data.

The findings suggest no significant differences between the overall efficiency of conventional and Islamic banks. However, it was noted that, on average, banks are more efficient in using their resources compared to their ability to generate revenues and profits. The average bank lost an opportunity to receive 27.9 percent more revenue, given the same amount of resources. Similarly, the average bank lost the opportunity to make 20.9 percent more profits utilising the same level of inputs. Clearly there is substantial room for improvement in cost minimisation and revenue and profit maximisation in both banking systems. The size and age factor did not significantly influence the efficiency scores in both banking streams.

This research is substantially different from the prior work in this area in three main ways. First, it investigates cost, revenue, and profit efficiency, whereas previous studies focus on cost, profit, or cost and profit efficiency. Also, no previous studies have compared conventional and Islamic banks. Second, this study distinguishes differences among big versus small, and old versus new banks, which allows more detailed insights on the efficiency issue. Third, the age issue in Islamic banks has been addressed, so far undocumented.

The present study aims to conduct a numerical investigation of a novel film cooling scheme combining in‐hole impingement cooling and flow turbulators with traditional downstream film cooling, and was originally proposed by Pratt & Whitney Canada for high temperature gas turbine applications.

Steady‐state simulations were performed and the flow was considered incompressible and turbulent. The CFD package FLUENT 6.1 was used to solve the Navier‐Stokes equations numerically, and the preprocessor, Gambit, was used to generate the required grid.

It was determined that the proposed scheme geometry can prevent coolant lift‐off much better than standard round holes, since the cooling jet remains attached to the surface at much higher blowing rates, indicating a superior performance for the proposed scheme.

The present study was concerned only with the downstream effectiveness aspect of performance. The performance related to the heat transfer coefficient is a prospective topic for future studies.

Advanced and innovative cooling techniques are essential in order to improve the efficiency and power output of gas turbines. This scheme combines in‐hole impingement cooling and flow turbulators with traditional downstream film cooling for improved cooling capabilities.

This new advanced cooling scheme both combines the advantages of traditional film cooling with those of impingement cooling, and provides greater airfoil protection than traditional film cooling. This study is of value for those interested in gas turbine cooling.

The main objective of this study is to identify the main determinants of the Islamic banks’ performance in Gulf Cooperation Council (GCC) regions.

The research uses both static model (fixed effects and random effects) and Generalized method of Moments (GMM). The data for this study are obtained from the annual reports of 29 Islamic banks from GCC countries using Bankscope database for the period from 2005 to 2013.

The empirical findings reveal that Islamic banks’ specific factors such as the equity financing and bank size are positive and statistically significant to the profitability of Islamic banks. The operating efficiency ratio is negatively and statistically significant to return on asset. It is also found that macroeconomic variables such as money supply and inflation are negatively and statistically significant to the performance of Islamic banks whereas oil price has been found positive and statistically significant to the performance of Islamic banks in the GCC region.

The present study seeks to fill a demanding gap in the literature by providing new empirical evidence on the factors that influence the profitability of the Islamic banking sector in GCC regions.

These findings have significant contribution to the literature by comprehensively clarifying and critically analyzing the current state of profitability among the Islamic banks in GCC regions.

Numerical simulations were carried out for two cooling schemes, a circular hole and a louver cooling scheme, at the leading edge of a rotor blade in a complete turbine stage.

Two holes were positioned at the leading edge of a rotating blade, one on the pressure side and the other on the suction side. The methodology was validated with a circular hole case. Numerical results of cooling effectiveness for three blowing ratios at three rotational speeds were successfully obtained. Both blowing ratio and rotating speed of the rotor affect the cooling effectiveness level.

It was shown that for the circular hole, the blowing ratio is the dominant factor at low blowing ratios and the rotational speed is the dominant factor at high blow ratios when jet is prone to lift off in determining the cooling effectiveness level. For the louver scheme, a higher rotational speed leads to a higher level of cooling effectiveness since jet liftoff is avoided.

There are only a few studies of film cooling on a rotational turbine blade and very few studies of film cooling at the leading edge of a rotating turbine blade in the open literature. The present work presents a challenging CFD case. The analysis of film cooling at the leading edge of an airfoil was presented, which sheds light on the physics of film cooling and should prove helpful to the cooling designs of turbine blades.

This study aims to investigate the impact of entrepreneurial education (EE), financial support (FS) and role models (RMs) on one’s attitude towards entrepreneurship (ATE) and on entrepreneurial intention (EI) based on the theory of planned behaviour.

In this study, quantitative research design, a deductive approach and purposive sampling have been used to collect data from 352 individuals from various Malaysian higher education institutions. The data were analysed using partial least squares structural equation modelling.

The findings have provided interesting insights into how EE, FS and RMs have a significant impact on one’s ATE and their EI. Surprisingly, RMs did not emerge as a significant predictor of EI. However, it is worth noting that mediating relationships were of significance, indicating that one’s ATE plays a substantial mediating role between EE, FS, RMs and EIs.

To the best of the authors’ knowledge, this study is among the few that investigate the relationships between RMs, FS and EE in relation to enhancing EIs through the mediating role of one’s ATE in Malaysia. Based on the findings of this study, stakeholders in Malaysia’s education sector are being urged to develop policy guidelines for the designing and teaching of entrepreneurship education as well as to develop FS mechanisms for business start-ups. They are also being encouraged to expose students to entrepreneurial RMs to improve their ATE and their EIs.

One of the most critical gas turbine engine components, the rotor blade tip and casing, is exposed to high thermal load. It becomes a significant design challenge to protect the turbine materials from this severe situation. The purpose of this paper is to study numerically the effect of turbine inlet temperature on the tip leakage flow structure and heat transfer.

In this paper, the effect of turbine inlet temperature on the tip leakage flow structure and heat transfer has been studied numerically. Uniform low (LTIT: 444 K) and high (HTIT: 800 K) turbine inlet temperature, as well as non‐uniform inlet temperature have been considered.

The results showed the higher turbine inlet temperature yields the higher velocity and temperature variations in the leakage flow aerodynamics and heat transfer. For a given turbine geometry and on‐design operating conditions, the turbine power output can be increased by 1.33 times, when the turbine inlet temperature increases 1.80 times. Whereas the averaged heat fluxes on the casing and the blade tip become 2.71 and 2.82 times larger, respectively. Therefore, about 2.8 times larger cooling capacity is required to keep the same turbine material temperature. Furthermore, the maximum heat flux on the blade tip of high turbine inlet temperature case reaches up to 3.348 times larger than that of LTIT case. The effect of the interaction of stator and rotor on heat transfer features is also explored using unsteady simulations. The non‐uniform turbine inlet temperature enhances the heat flux fluctuation on the blade tip and casing.

The increase of turbine inlet temperature is usually proposed to achieve the higher turbine efficiency and the higher turbine power output. However, it has not been reported how much the heat transfer into the blade tip and casing increases with the increased turbine inlet temperature. This paper investigates the heat transfer distributions on the rotor blade tip and casing, associated with the tip leakage flow under high and low turbine inlet temperatures, as well as non‐uniform temperature distribution.

To develop a reliable methodology and procedure of simulating the jet‐in‐crossflow using the current turbulence models and numerically investigate the cooling performance of a new scheme for the engines of next generation.

A new advanced film cooling scheme is proposed based on the literature survey and a systematic methodology developed to successfully predict the right level of heat transfer in the CFD simulation of film cooling.

The proposed cooling scheme gives considerable lower heat transfer coefficient at the centerline in the near hole region than the traditional cylindrical hole, especially at a high blowing ratio when traditional cylindrical hole undergoes liftoff.

The number of cooling holes in the computational domain is limited by the speed of the computers used.

The new methodology can be used to numerically test new cooling schemes in the design of turbine blades and to provide useful information/data under actual working conditions to design engineers.

This paper provides some useful information on the simulation of film cooling in terms of the performance of different turbulence models and wall treatments and also sends some valuable messages regarding the design of cooling scheme of turbine blades to the technical community.

Although much research has investigated the impact of social capital on objective career success, the process through which this relation is established remains under-explored. In addition, studies conducted in the Middle East and North Africa region are scarce. The purpose of this paper is to examine and potentially bridge these gaps.

Data were collected via survey from 348 Tunisian bankers. Path analysis using AMOS was used to explore the relationships between mentoring received, network resources training and development and objective career success. For testing the mediating hypotheses, the authors employed bootstrapping.

Results support the conjecture that social capital is useful for career success. The authors found that when the employees receive mentoring, they seem to develop more instrumental network resources, and consequently they have wider access to training and development, which, in turn, will be related to better promotion outcomes. However, expressive network resources were not related to objective career success, and training and development did not mediate the relationship between these network resources and career success.

To the authors’ knowledge, this is one of the first studies to explore the relationship between social capital and objective career success in the Tunisian context. This paper also reveals the mediating role of training and development in the above relationship. These findings add to the cross-cultural literature on careers.

The purpose of this paper is to comparatively examine the cost and the overlooked revenue efficiency of Islamic and commercial banks in the aftermath of the crisis, operating in nine MENA-based countries during the 2010-2017 financial period, where the established empirical work is relatively limited. The authors also update the research where they use recent data sets and they provide for a targeted, structured literature review pre- and post-crisis in the Gulf region.

The authors examine cost and revenue efficiency of 25 major Islamic banks (IBs) and 25 major conventional banks (CBs). They conduct tests on the determinants of such variables. In the first stage of the analysis, they measure efficiency by using the data envelopment analysis (DEA) technique. The analysis performs regressions where these also reveal that the bank efficiency index is influenced by various bank type-specific attributes. It also seems that tighter restrictions on bank activities are negatively associated with bank efficiency. Second stage analysis, which accounts for banking environment and bank-level characteristics, confirms these results.

Conventional banks are both more cost and revenue efficient than Islamic banks over the period under examination. The analysis also reveals that the bank efficiency index is influenced by bank-type attributes. Greater presence of fixed capital resources has positive effects on growth in both Islamic and conventional banking. The major constraints impeding Islamic banking growth include labour costs. The authors examine whether and how bank-type orientation affects the cost and revenue efficiency of conventional and Islamic banks. They find that post-crisis Islamic banks underperform their conventional counterparts on both accounts within a mixed banking system.

This study did not include comparative data before the 2008 financial crisis. There is also a great deal of heterogeneity among Islamic banks in the samples that have been examined here and by other researchers and the constructed efficiency scores should be interpreted cautiously as divergent Islamic banks are pooled in the same samples.

This study identified factors that may help bank managers to improve their financial outlook by controlling revenue and cost efficiency profitability. These factors could as well help to understand how some indicators affect both cost and revenue efficiency, particularly in Islamic banking. It also seems that tighter restrictions on Islamic bank activities are negatively associated with bank efficiency. Islamic banks that directly compete with their conventional counterparts in the aftermath of the crisis are less efficient on both the cost and revenue frontiers. They are potentially hindered by the differential regulations of supervising authorities in dual banking systems.

The authors provide recommendations regarding regulatory and other issues that are relevant to Islamic banking and further research is suggested. Findings are relevant to a variety of stakeholders (managers, policymakers and regulators). Islamic banking authorities could re-examine the benefits of partially moving to a more standardized/conventional system of banking by lifting some trading restrictions. In addition, developing and maintaining managerial skills is an indispensable instrument for the long-term endurance of any system. A related aspect is thus an effort to determine the holistic efficiency (including managerial) of Islamic banks as a guide for policymakers to improve managerial performance.

There is relatively limited empirical work that investigates the efficiency between Islamic and conventional banking in the aftermath of the crisis in the Gulf region despite the growing importance of this region on political and economic levels. The authors also examine the revenue efficiency measure often under-researched in the literature and particularly important for comparative studies. Overseas-owned banks have attained much higher infiltration levels in middle-eastern countries over the past decade. It has also been suggested that market penetration differences may also be related to bank efficiency concerns among countries and their financial systems as opposed to types of banks.