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Spark ignition (SI) engines are used in a wide area in the transportation industry, from road vehicles to piston-prop aircraft. On the other hand, the decrease in reserves of fossil fuels used in SI engines and the increase in greenhouse gas emissions makes the use of alternative fuels inevitable. In this paper, optimization of in-cylinder combustion and engine performance parameters by intake-charge conditions [i.e. intake-air temperature, injection timing and exhaust gas recirculation (EGR)] in a hydrogen (H₂)-fueled small SI engine is performed.

Experimental studies were performed at a 1,600 rpm engine speed of a single-cylinder, air-cooled engine having a stroke volume of 476.5 cm³, maximum output power of 13 HP and torque of 25 Nm. The hydrogen-fueled SI engine was operated by a lean air-fuel mixture (ϕ = 0.6) under wide-open throttle (WOT) conditions.

The findings of the paper show that improvements can be achieved in in-cylinder combustion, indicated engine performance, exhaust NO_x emissions with optimum intake-air temperature, the start of H₂ injection and the ERG rate.

It has been determined that a 32°C intake-air temperature, 395°C (bTDC) start of H₂ injection, and 5%–10% EGR rates are the most suitable values for the examined hydrogen fueled SI engine.

Hydrogen is a usable alternative fuel for SI engines used in a wide area from road vehicles to piston-prop aircraft engines. However, a number of problems remain that limit hydrogen fueled SI engines to some extent, such as backfire, a decrease of engine power, and high NO_x emissions. Therefore, it is appropriate to examine the effects of intake-charge conditions on in-cylinder combustion, engine performance, and NO_x emissions parameters in a hydrogen fuelled SI engine.

This study seeks the effect on static thrust, thrust specific energy consumption (TSEC) and exhaust emissions of euro diesel-hydrogen dual-fuel combustion in a small turbojet engine.

Experimental studies are performed in a JetCat P80-SE type small turbojet engine. Euro diesel and hydrogen is fed through two different inlets in a common rail distributing fuel to the nozzles. Euro diesel fuel is fed by a liquid fuel pump to the engine, while hydrogen is fed by a fuel-line with a pressure of 5 bars from a gas cylinder with a pressure of approximately 200 bars.

At different engine speeds, it is found that there is a decrease at the TSEC between a range of 1% and 4.8% by different hydrogen energy fractions (HEF).

The amount of hydrogen is adjusted corresponding to a range of 0–20% of the total heat energy of the euro diesel and hydrogen fuels. The small turbojet engine is operated between a range of 35,000 and 95,000 rpm engine speeds.

On the other hand, remarkable improvements in exhaust emissions (i.e. CO, CO₂, HC and NO_x) are observed with HEFs.

This is through providing improvements in performance and exhaust emissions using hydrogen as an alternative to conventional jet fuel in gas turbine engines.

The income structure of banks has undergone a notable change in recent decades; therefore, non-interest-based activities have gained much attention. This paper aims to examine the impact of income diversification on bank performance in Pakistan.

A balanced panel data set of 20 Pakistani commercial banks is used from 2007 to 2020. The random effect model is employed to test the relationship between income diversification and financial performance.

The empirical results indicate a significant positive impact of income diversification of banks on risk-adjusted returns on assets and equity. Moreover, while banks' risk-adjusted profit performance improves with the increase in bank size, equity ratio and loan ratio, it deteriorates with high credit risk and technology. However, geographical diversification does not explain financial performance in all the risk-adjusted return on equity models. Among the macroeconomic factors, the interest rate influences bank risk-adjusted returns positively, whereas gross domestic product and inflation rate have a negative effect on banks' financial performance.

To the best of the author's knowledge, this study is the first to empirically investigate the relationships between income diversification and the risk-adjusted profits of Pakistani-listed commercial banks. This study has implications for regulators and policymakers of commercial banks.

The purpose of this paper is to understand whether circumstantial factors in Turkey create a unique approach to human resource management (HRM) determining its place on the convergence and divergence continuum.

Turkish HRM literature, based on 39 journal articles published between the years 1998 and 2018, are analyzed through an institutional theory lens using content analysis.

The ambiguity of the convergence and divergence issue in Turkey may be argued as HRM is still not considered as a primary management function in Turkey. There appear to be only a small number of original studies that preserve cultural values as well as follow new trends within the discipline.

This study broadens the understanding of the developmental trajectories of HRM by examining the context, history and advancement of HRM in Turkey as an example of developing economies.

The flow and heat transfer of a hybrid nanofluid composed of kerosene and ZnO-Al2O3 nanoparticles (NPs) is investigated. The flow occurs over complex surfaces with stretching and shrinking features. The base fluid is electrically conducting, and an external magnetic field is added so that the nanofluid and the electric field are in equilibrium. Irrotational flow with viscous dissipation effects is considered.

The governing equations of the system are formulated, and a similarity transformation is used to convert the system of equations into ordinary differential equations, which are solved numerically. The friction coefficient of the flow and the Nusselt number are calculated for a wide range of parameters, and the results are presented in graphical form. In addition, dual solutions of the problem were noticed to occur for a certain range of the unsteadiness parameter. A stability analysis has been performed and presented to elucidate the behavior of these dual solutions.

For the solution of the upper branch, the velocity and temperature profiles of the nanofluid are enhanced by increasing the magnetic field parameter M, but the same variables decrease in the solution of the lower branch. The same trend is detected for the velocity of the fluid with the suction parameter. The temperature of the nanofluid decreases in both branches of the solution by increasing the Prandtl number. Similarly, they decrease with the suction parameter. The temperature of the nanofluid slightly increases in both branches of the solution by increasing the Eckert number. With the stability analysis the authors performed, it was determined that the solution is stable in the upper branch, but unstable in the lower branch.

The kerosene nanofluid with hybrid Zinc/Aluminum-oxide is presented for the first time in the literature.

The purpose of this paper develops a conceptual model of social influence for Internet banking adoption (IBA) using social networking platforms (SNPs). It identifies the antecedents of social influence that can positively and negative influence the IBA among a targeted population of conventional and Islamic banks. Moreover, this paper contributes various factors to social influence theory with the purpose of enhancing its implication in the context of Internet banking uptake in developed and developing countries.

This study uses a social constructivism approach to understand customer experiences, thoughts, knowledge, awareness and perceptions in relation to IBA. For this study, data were collected from 30 respondents using semi-structured interviews and purposive sampling.

Social influence comprises customer recommendations, suggestions, ratings, reviews, experiences and thoughts regarding the IBA of Islamic and conventional banks. The findings reveal that social reviews, social experts, social consensus, social responsibility and social perceptions are the key antecedents of social influence that can enhance IBA of SNPs. The research finds that positive social reviews, expert support, consensus, social responsibility and social perceptions are significant in relation to conventional Internet banking. The respondents revealed serious concerns about the privacy of their personal and financial information especially in relation to Islamic banks.

The effective and well-organized use of SNPs can foster service reviews, word of mouth, higher levels of service awareness, interactive communication, social consensus and social trust to drive the adoption of Internet banking. This study proposes the conceptual model which has positive business implications and provides the banks direction to use the SNPs to their advantage to influxes their customers to adopt the use of Internet banking.

Most previous studies have used technology acceptance model, theory of planned behavior and unified theory of acceptance and the use of technology theories in the adoption of technology and IBA. These theories have not fully illuminated the role of social content as a way to enhance or decrease the number of customers in conventional and Islamic banks. This study develops social influence theory by exploring several dimensions (i.e. social reviews, awareness, consensus, cooperation and experts support) in the context of IBA for users of SNPs. Social influence can create more reviews and can lead to more prepurchase information. It can drive customer inquiries and engagement and can inform purchase decisions for IBA. On the other hand, it can motivate existing customers of Islamic banks to use conventional banking services due to effective word of mouth.

One of the existing and commonly used solar energy harvesting devices is the parabolic trough solar collector (PTSC). Because of their ability to operate in low and medium temperatures, parabolic trough concentrators are widely used in power generation plants and industrial process heating applications. Therefore, the investigation of how different operating conditions affect these devices’ overall efficiency has received a great deal of attention in the recent decade. This study aims to enhance the thermal performance of the PTSC and reduce the system cost.

In the novel configuration, a noncirculated nanofluid absorbs solar radiation through a glass wall. The base fluid was synthetic oil (5W30), and the nanoparticles used were copper oxide. The heat captured is immediately absorbed by the water circulating inside the copper tube immersed in the nanofluid. ANSYS FLUENT 15.0 was used for carrying out computational fluid dynamics simulations for two models of single and triple copper tubes. The experimental results obtained from a test rig constructed for this purpose were compared with the numerical outcomes of the single copper tube model.

The findings of the simulation demonstrated that performance was superior for the single copper tube model over the triple copper tube model. The numerical findings of the single copper tube model were compared with the experimental results. The numerical and experimental results differed from 3.17% to 5.6%. Investigations were carried out to study the effects of varying the volumetric flow rate of (20, 40, 60 and 80 L/h) and water inlet temperatures of (300, 315 and 330 K) on the effectiveness and performance of the newly developed model. Additionally, two nanofluid volume fractions of 0.05% and 0.075% were used for investigating their effect on the performance of the novel configuration. According to the findings, the highest thermal efficiency of 55.31% was recorded at 0.075% concentration and 80 L/h volume flow rate.

In this study, a novel direct absorption solar collector configuration using a noncirculated nanofluid was designed to enhance the thermal efficiency of PTSC. This new approach makes it possible to boost the thermal performance of the PTSC and lower the system’s cost.

In the current competitive world of business, it is important that every individual strives to be competitive to elevate his/her life status and creates a bright-looking future. The purpose of this study is to lay emphasis on the Jordanian hospitality industry in light of the investigation as to how organizational commitment, leadership style and organizational culture influence organizational citizen behavior (OCB) with the moderating role of job satisfaction in the relationship.

The study explores the determinants based on the responses obtained from the employees working in five-star hotels in Jordan. A small sample was exposed to SPSS software analysis for instrument validity, reliability and data normality.

The study validated the reliability of the instrument in conducting a preliminary study, obtaining reasonable normality and highly reliable coefficients of measures (0.753-0.938).

The study validated the effectiveness of the instrument that examined different specific antecedents of OCB.